• Publication Date:
  • Publication Type:
    Final Rule
  • Fed Register #:
    59:40964-41162
  • Standard Number:
  • Title:
    Occupational Exposure to Asbestos

DEPARTMENT OF LABOR

Occupational Safety and Health Administration

29 CFR Parts 1910, 1915, and 1926

RIN: 1218-AB25

Occupational Exposure to Asbestos

AGENCY: Occupational Safety and Health Administration, Department of Labor.

ACTION: Final rule.

SUMMARY: These final standards amend the Occupational Safety and Health Administration's (OSHA's) standards issued June 17, 1986 (51 FR 22612, 29 CFR 1910.1001, June 20, 1986) for occupational exposure to asbestos in general industry, and the construction industry, 29 CFR 1926.1101 (previously 1926.58). In addition, they include a separate standard covering occupational exposure to asbestos in the shipyard industry, (29 CFR 1915.1001). Major revisions in these standards include a reduced time-weighted-average permissible exposure limit (PEL) of 0.1 fiber per cubic centimeter (f/cc) for all asbestos work in all industries, a new classification scheme for asbestos construction and shipyard industry work which ties mandatory work practices to work classification, a presumptive asbestos identification requirement for "high hazard" asbestos containing building materials, limited notification requirements for employers who use unlisted compliance methods in high risk asbestos abatement work, and mandatory methods of control for brake and clutch repair.

Most of the revisions in these amended standards are the final response to an order of the Court of Appeals for the District of Columbia Circuit, Building and Construction Trades Department v. Brock, 838 F. 2d 1258, (D.C. Cir 1988), which had upheld the 1986 standards in major respects, but which had remanded certain issues for reconsideration. OSHA had made earlier changes in response to the court order on December 14, 1989 (54 FR 52024, December 20, 1989), and on February 5, 1990 (55 FR 3724).

OSHA believes that these final standards fully address all of the concerns of the participants in this rulemaking and are responsive to all issues remanded by the court for reconsideration.

DATES: The effective date of these amendments is October 11, 1994. Various start-up dates are specified in the standards.

FOR FURTHER INFORMATION CONTACT: Mr. James F. Foster, Director of Information and Consumer Affairs, Occupational Safety and Health Administration, U.S. Department of Labor, Room N3647, 200 Constitution Avenue, NW., Washington, DC 20210, telephone (202) 219-8151.

Supplementary Information:

Table of Contents

I. Regulatory History
II. Pertinent Legal Authority
III. Summary and Explanation of Revised Standards
a. General Issues
b. Regulatory Text Issues
IV. Final Regulatory Impact and Regulatory Flexibility Analysis
V. Clearance of Information Collection Requirements
VI. Authority and Signature
VII. Amended Standards

I. Regulatory History

OSHA has regulated asbestos several times as more information has become available. Asbestos rulemakings marked the early years of the Agency. A 12 f/cc permissible exposure limit (PEL) for asbestos was included in the initial promulgation on May 29, 1971 (36 FR 10466) of OSHA standards pursuant to Section 6(a) of the Act. In response to a petition by the Industrial Union Department of the AFL-CIO, OSHA issued an Emergency Temporary Standard (ETS) on asbestos on December 7, 1971, which established a PEL of 5 f/cc as an 8-hour time-weighted average (TWA) and a peak exposure level of 10 f/cc.

In June 1972, OSHA promulgated a new final standard that established an 8-hour TWA PEL of 5 f/cc and a ceiling limit of 10 f/cc. These limits were intended primarily to protect employees against asbestosis, and it was hoped that they would provide some incidental degree of protection against asbestos induced forms of cancer. Effective July 1976, OSHA's 8-hour TWA limit was reduced to 2 f/cc and this limit remained in effect up to the effective date of the revised 1986 standards.

In October 1975, OSHA published a notice of proposed rulemaking (40 FR 47652) to revise the asbestos standard because the Agency believed that "sufficient medical and scientific evidence has been accumulated to warrant the designation of asbestos as a human carcinogen" and that advances in monitoring and protective technology made re-examination of the standard "desirable." This proposal would have reduced the 8-hour TWA to 0.5 f/cc and imposed a ceiling limit of 5 f/cc for 15 minutes. The 1975 proposal would have applied to all industries except construction.

At that time no separate proposal applicable to the construction industry was developed by the Agency.

On May 24, 1983 OSHA consulted with the Advisory Committee for Construction Safety and Health ("ACCSH") concerning the applicability of any new asbestos standard to the construction industry. ACCSH endorsed OSHA's position that any new PEL adopted for general industry should also apply to the construction industry (Ex. 84-424).

On November 4, 1983 OSHA published an ETS for asbestos (48 FR 51096). The ETS marked a new regulatory initiative, related to, but not part of the 1975 proceeding. The ETS was held invalid by the U.S.Circuit Court of Appeals for the Fifth Circuit on March 7, 1984.

Subsequently, OSHA published a notice of proposed rulemaking (49 FR 1416, April 10, 1984) for a standard covering occupational exposure to asbestos in all work places subject to the Act. Pursuant to Section 6(c) of the Act, the ETS also served as a proposed rule. On June 17, 1986, OSHA issued two revised standards, one governing occupational exposure to asbestos in general industry workplaces, the other applicable to construction workplaces (51 FR 22612 et seq., June 20, 1986). Effective July 21, 1986, the revised standards amended OSHA's previous asbestos standard issued in 1972. The 1986 standards explicitly applied to occupational exposure to non-asbestiform tremolite, anthophyllite and actinolite. After a subsequent and separate rulemaking proceeding OSHA has deleted these minerals from the scope of the asbestos standards. (57 FR 24310, June 8, 1992).

The separate comprehensive asbestos standards for general industry and construction which were issued in 1986 shared the same permissible exposure limit (PEL) and most ancillary requirements. Both standards reduced the 8-hour time weighted average (TWA) PEL tenfold to 0.2 f/cc from the previous 2 f/cc limit. Specific provisions were added in the construction standard to cover unique hazards relating to asbestos abatement and demolition jobs.

Several major participants in the rulemaking proceeding including the AFL-CIO, the Building and Construction Trades Department (BCTD) of the AFL-CIO, and the Asbestos Information Association (AIA), challenged various provisions of the revised standards. On February 2, 1988, the U.S. Court of Appeals for the District of Columbia issued its decision upholding most major challenged provisions, but remanding certain issues to OSHA for reconsideration (BCTD, AFL-CIO v. Brock, 838 F.2d 1258). The Court determined that OSHA had not adequately explained why it was not adopting certain recommended provisions in light of evidence suggesting that those provisions would be feasible to implement and would provide more than a de minimis benefit for worker health. The Court also ordered OSHA to clarify the regulatory text for two provisions and found one provision, a ban of spraying asbestos-containing products, unsupported by the record. In addition, OSHA's failure to adopt a short-term exposure limit (STEL) was ordered to be reconsidered within 60 days of the Court's mandate. In partial response, OSHA issued a STEL of 1 f/cc measured over a 30-minute sampling period, on September 14, 1988 (53 FR 35610).

In response to additional petitions by BCTD and the AFL-CIO, the Court, in an October 30, 1989 order, divided the remand issues into three categories as follows. With respect to three issues, the Court ordered OSHA to take action by December 14, 1989. These issues were:

Issue 1. formally delete the ban on the spraying of asbestos-containing materials;

Issue 2. clarify that periodic monitoring in the construction industry must be resumed after conditions change; and

Issue 3. Clarify the exemption for "small-scale, short duration operations" from the negative-pressure enclosure requirements of the construction standard to limit the exemption to work operations where it is impractical to construct an enclosure because of the configuration of the work environment.

OSHA issued its response on these issues on December 14, 1989 (54 FR 52024, December 20, 1989). In that document OSHA (1) removed the ban on the spraying of asbestos-containing materials; (2) changed the regulatory text to clarify that construction employers must resume periodic monitoring whenever there has been a change in process, control equipment, personnel or work practices that may result in new or additional asbestos exposure; and (3) explained why OSHA was not amending the regulatory text to clarify the limited exemption for "small-scale, short-duration operations" in the construction industry standard, but instead would institute rulemaking on this issue.

With respect to the second group of issues, the Court ordered OSHA to complete its response on the existing record by January 28, 1990. These issues are:

Issue 4. The possibility of further regulations governing employee smoking controls;

Issue 5. The effectiveness levels of various respirators and OSHA's policy of requiring respirators to protect workers at only PEL level; and

Issue 6. The possibility of bi-lingual warnings and labels for employers with a significant number of non-English-speaking employees.

The Court stated that if OSHA determines that these issues could not be resolved on the existing record, OSHA may explain why and commence new rulemaking instead.

On January 28, 1990, OSHA issued its response on these issues (55 FR 3724, February 5, 1990). In that document, OSHA: (1) prohibited workplace smoking in areas where occupational exposure to asbestos takes place; expanded training requirements to include information about available smoking cessation programs; required the distribution of self-help smoking cessation material; and, required a written opinion by the physician stating that the employee has been advised of the combined dangers of smoking and working with asbestos; (2) explained how and why the 1986 respiratory protection standards will reduce employee risk below that remaining solely as a result of the PEL, and that the effectiveness levels of respirators are under review; and (3) required employers to ensure that employees working in or near regulated areas understand warning signs, and required training programs to specifically instruct employees as to the content and presence of signs and labels.

Finally, as to the third group of three remaining remand issues, the Court ordered OSHA to resolve these issues after rulemaking. These issues are:

Issue 7. The establishment of operation-specific permissible exposure limits;

Issue 8. The extension of reporting and information transfer requirements; and

Issue 9. The expansion of the competent person requirement to all employers engaged in any kind of construction work.

In addition, the Court granted OSHA's unopposed request to publish the Notice of Proposed Rulemaking on this group of issues on April 13, 1990, to allow sufficient time to consult with the Advisory Committee on Construction Safety and Health (ACCSH). Under the Construction Safety Act (40 USC 333) and regulations in 29 CFR 1911.10 and 29 CFR 1912.3, OSHA was required to consult with that committee in the formulation of regulatory proposals which would apply to employment in construction. OSHA presented the proposed regulatory text and pertinent explanatory materials to the ACCSH and consulted with them on March 14, 1990. The Committee submitted comments and suggestions which were discussed in the proposal. The Court, on May 2, 1990 granted OSHA's further motion and extended the time to issue the proposal until July 12, 1990, in order to allow coordination of the proposal with other regulatory agencies, in particular EPA.

The proposed revisions were published July 20, 1990 (55 FR 29712). The date for close of the public comment period in the NPRM was September 25, 1990 with the public hearing scheduled to commence October 23, 1990. However, several interested parties requested additional time for comment on the NPRM due to the breadth of issues it presented. OSHA felt the objective of developing a complete rulemaking record would be served and extended the period for submission of public comments and for notices to appear at the informal hearing until December 3, 1990. The Agency also rescheduled the informal hearing to begin January 23, 1991. In the notice extending the time periods, OSHA also explained more clearly that the ACCSH report referenced in the NPRM was submitted by the labor representatives on that committee and not by the committee as a whole (55 FR p. 38703, September 20, 1990).

The informal hearing was held for 13 days from January 23 to February 8, 1991. At the close of the hearing Administrative Law Judge Sheldon Lipson set April 12, 1991 as the close of the post-hearing comment period and June 12, 1991 as the close of the post-hearing briefing period. Subsequently on request, Judge Lipson extended these periods to April 26 and June 26 respectively. BCTD requested OSHA extend the post-hearing briefing period 4 weeks to allow additional time to fully address all issues of concern due to the extent and complexity of the records. OSHA granted this request and notified participants that the post-hearing briefing period was extended to July 24, 1991.

On November 3, 1992, by Federal Register notice, OSHA re-opened the comment period to allow supplementary public comment on options to protect workers from inadvertent exposure to asbestos in buildings (57 FR 49697). This issue, not part of the Court's remand order, was broached by the Agency in the preamble to the proposal, and had been the subject of litigation brought by Service Employees International Union (SEIU) against EPA. In 1988 the Service Employees International Union, AFL-CIO petitioned the Environmental Protection Agency for regulation of asbestos in public and commercial buildings and subsequently sued the Agency. This resulted in the convening of a series of "Policy Dialogue" meetings established by EPA in an attempt to reach agreement on issues concerning asbestos in public and commercial buildings. As discussed in the NPRM of July 20, 1990, OSHA and a variety of other interested parties participated in the meetings which took place between May 1989 and May 1990. These groups included realty interests, lenders and insurance interests, unions, asbestos manufacturers, public interest groups, asbestos consultants and contractors and states. The group failed to agree on all issues, but did generally agree that the presence of asbestos should be known to building service workers. The major area of disagreement in the group dealt with the characterization of risk to general building occupants and office workers. The group also did not agree on the need for specific federal asbestos inspection requirements.

SEIU and other unions also participated in this rulemaking and urged OSHA to issue a building inspection rule. After discussions with EPA and review of the record concerning how best to protect employees against unknowing exposure the Agency published a request for comment on a regulatory approach to protect building service workers. The approach would require certain high-risk materials in accessible building/facility areas be designated presumptive asbestos containing materials and thus be treated as if they contained asbestos, until or unless the presumption was rebutted through sampling or specific information in the owner's possession relation to construction specifications. The notice also asked for comments on the Health Effects Institute (HEI) report which had been submitted to the record after the close of the post-hearing briefing periods. The notice resulted in submission of an additional 60 sets of comments, and the comment period closed on January 4, 1993.

The record of this rulemaking consists of over 55,000 pages. OSHA has worked closely with EPA so that the regulations of both agencies are compatible to the extent OSHA's mandate allows.

II. Pertinent Legal Authority

Authority for issuance of this standard is found primarily in sections 6(b), 8(c), and 8(g)(2) of the Occupational Safety and Health Act of 1970 (the Act), 29 U.S.C. 655(b), 657(c), and 657(g)(2) and in the Construction Safety Act, 40 U.S.C. 333. Section 6(b)(5) governs the issuance of occupational safety and health standards dealing with toxic materials or harmful physical agents. Section 3(8) of the Act defines an occupational safety and health standard as:

* * * A standard which requires conditions, or the adoption or use of one or more practices, means, methods, operations, or processes, reasonably necessary or appropriate to provide safe or healthful employment and places of employment.

The Supreme Court has said that section 3(8) applies to all permanent standards promulgated under the Act and requires the Secretary, before issuing any standard, to determine that it is reasonably necessary and appropriate to remedy a significant risk of material health impairment. Industrial Union Department v. American Petroleum Institute, 448 U.S. 607 (1980).

The "significant risk" determination constitutes a finding that, absent the change in practices mandated by the standard, the workplaces in question would be "unsafe" in the sense that workers would be threatened with a significant risk of harm. Id. at 642. A significant risk finding, however, does not require mathematical precision or anything approaching scientific certainty if the "best available evidence" does not warrant that degree of proof. Id. at 655-656; 29 U.S. 655 (b)(5). Rather, the Agency may base its finding largely on policy considerations and has considerable leeway with the kinds of assumptions it applies in interpreting the data supporting it, Id. 655-656; 29 U.S. 655(b)(5). The Court's opinion indicates that risk assessments, which may involve mathematical estimates with some inherent uncertainties, are a means of demonstrating the existence of significant risk.

The court further stated:

It is the Agency's responsibility to determine in the first instance what it considers to be a "significant" risk. Some risks are plainly acceptable and others are plainly unacceptable. If, for example, the odds are one in a billion that a person will die from cancer by taking a drink of chlorinated water, the risk clearly could not be considered significant. On the other hand, if the odds are one in a thousand that regular inhalation of gasoline vapors that are 2% benzene will be fatal a reasonable person might well consider the risk significant and take the appropriate steps to decrease or eliminate it. (I.U.D. v A.P.I., 448 U.S. et 655).

OSHA has always considered that a working lifetime risk of death of over 1 per 1000 from occupational causes is significant. This has been consistently upheld by the courts. See the recent discussion in the cadmium preamble 57 FR 42102, 42204 and the earlier asbestos preambles.

OSHA believes that compliance with these final amendments to reduce the PEL to 0.1 f/cc as a time-weighted average measured over 8 hours will further reduce a significant health risk which existed after imposing a 0.2 f/cc PEL. OSHA's risk assessment accompanying the 1986 standard, showed that lowering the TWA PEL from 2 f/cc to 0.2 f/cc reduces the asbestos cancer mortality risk from lifetime exposure from 64 deaths per 1,000 workers to 7 deaths per 1,000 workers. OSHA estimated that the incidence of asbestosis would be 5 cases per 1,000 workers exposed for a working lifetime under the TWA PEL of 0.2 f/cc. Counterpart risk figures for 20 years of exposure are excess cancer risks of 4.5 per 1,000 workers and an estimated asbestosis incidence of 2 cases per 1,000 workers.

OSHA's risk assessment also showed that reducing exposures to 0.1 f/cc would reduce excess cancer risk to 3.4 per 1,000 workers and a 20 year exposure risk to 2.3 per 1,000 workers. OSHA concludes therefore that reducing the exposure limit to 0.1 f/cc will further reduce significant risk.

OSHA's current estimates of employee exposure in the various operations covered by these standards are referenced in the Regulatory Impact Analysis found later in this document. Additional exposure estimates, based on record evidence are referenced throughout this document in the relevant preamble discussion concerning each operation.

In the Court of Appeals litigation, AIA challenged OSHA's use of the PEL to calculate the residual risk remaining after the standard is implemented. AIA contended that workers would actually be exposed to average levels significantly below the PEL because employers would be required to engineer down to levels well below the PEL to assure that random fluctuations would not result in an OSHA compliance officer measuring an exposure level over the PEL during a routine inspection. Therefore, AIA contended, in calculating residual risk, OSHA should assume that employees will be exposed to average levels that are between one-half and one-quarter of the PEL. The Court implied that such an argument might have merit if factually supported and suggested that OSHA should make its own calculations of the relation between permissible exposure limit and the actual exposures such a limit would produce. (838 F.2d at 1266) Having carefully considered the issue, OSHA concludes it would be unrealistic to base its risk assessment on the assumption that employers will engineer to levels significantly below the PEL. First, as discussed below, the PEL of 0.1 f/cc is at the limit of feasibility for those workplaces in which asbestos levels are most difficult to control, and an assumption that average exposures will be substantially below the PEL will clearly be unrealistic for such workplaces. Second, OSHA found in issuing the 1986 standard that AIA's argument about uncontrollable fluctuations was exaggerated because such fluctuations could be minimized through proper inspection and maintenance of engineering controls and through proper training and supervision of employees whose work practices affected exposure levels. (51 FR at 22653). Third, OSHA's enforcement policy gives employers the opportunity to show that a compliance officer's measurement over the PEL is unrepresentatively high and does not justify a citation, thus alleviating any concern employers might have that they will be cited on the basis of a single measurement that results from uncontrollable fluctuations. Fourth, even if some employers are sufficiently risk-averse to engineer down to well below the PEL to avoid a slight risk of citation, OSHA cannot base a realistic risk assessment on the assumption that most employers will do so.

The 0.1 f/cc level leaves a remaining significant risk. However as discussed below, and in earlier documents, OSHA believes this is the practical lower limit of feasibility for measuring asbestos levels reliably. However the work practices and engineering controls specified below for specific operations and required respirator use will in OSHA's view further reduce the risk. As discussed below, OSHA has carefully reviewed all the public suggestions to further reduce significant risk and has adopted those which have merit.

After OSHA has determined that a significant risk exists and that such risk can be reduced or eliminated by the proposed standard, it must set the standard "which most adequately assures, to the extent feasible on the basis of the best available evidence, that no employee will suffer material impairment of health* * *," Section 6(b)(5) of the Act. The Supreme Court has interpreted this section to mean that OSHA must enact the most protective standard necessary to eliminate a significant risk of material health impairment, subject to the constraints of technological and economic feasibility. American Textile Manufacturers Institute, Inc. v. Donovan, 452 U.S. 490(1981). The Court held that "cost-benefit analysis is not required by the statute because feasibility analysis is." Id. at 509.

Authority to issue this standard is also found in section 8(c) of the Act. In general, this section gives the Secretary authority to require employers to make, keep, and preserve records regarding activities related to the Act. In particular, section 8(c)(3) gives the Secretary authority to require employers to "maintain accurate records of employee exposures to potentially toxic materials or harmful physical agents which are required to be monitored or measured under section 6." Provisions of OSHA standards which require the making and maintenance of records of medical examinations, exposure monitoring, and the like are issued pursuant to section 8(c) of the Act.

Because the revisions to the asbestos standards are reasonably related to these statutory goals, the Secretary finds that these standards are necessary and appropriate to carry out is responsibilities under the Act.

"Response to recommendations of public to further reduce risk": As noted above, this rulemaking proceeding is a response to a remand order of the Court of Appeals for the D.C. Circuit. The Court determined that in the earlier 1986 rulemaking, OSHA had not sufficiently explained its decisions not to adopt certain regulatory provisions recommended by participants in that rulemaking. In particular, the Court of Appeals held that it is OSHA's "duty to keep adding measures so long as they afford benefit and are feasible, up to the point where (it) no longer finds significant risk," and that it is OSHA's duty to consider the reasonableness of adopting them. 838 F.2d at 1269. The Court noted that OSHA need not justify its failure to adopt all suggested provisions: rather, the Agency must defend not adopting only those provisions demonstrated by their advocates, "to be feasible to implement and will provide more than a de minimis benefit for worker health." The Court further explained, "(n)aturally the force of the evidence and argument that OSHA must offer to defend its choice will vary with the force of the proponent's evidence and argument." Id at 1271.

In this final rule, based upon the record evidence, OSHA is adopting certain regulatory recommendations made in the earlier rulemaking, is rejecting other recommendations, and is issuing other provisions which are based on, but are altered versions of yet other recommendations in the earlier rulemaking. In addition, new, different and expanded provisions also have been urged for adoption by participants in this rulemaking. These participants represent labor, public interest and industry interests. The Agency is adopting, rejecting and changing these recommendations as well.

A large portion of this preamble is devoted to the Agency's explanations of these regulatory decisions. OSHA believes that its reasons when it has adopted or has not adopted recommended provisions are well supported by the evidence and that the reasons for its choices are stronger than the contrary arguments. In general, OSHA believes that the extent of its burden to refute claims of benefit for a recommended provision depends on the extent of the supporting data. If the data are valid and extensive, OSHA's burden is greater. If however, the claim of benefit is based on opinion, refutation by OSHA need not be grounded in data, but may be based on OSHA's well reasoned and expert contrary opinion.

In sum, OSHA's decision not to adopt recommended provisions to reduce asbestos related risk reflects the Agency's expert judgment, often where available data creates considerable uncertainty, that the provisions would not offer more than de minimis benefit in reducing a still significant risk. Many recommendations were unsupported by data showing benefit. For example, it was recommended to prohibit high speed burnishing of asbestos-containing floor tile. However, the data do not show a measurable reduction of airborne asbestos fiber levels, based on actual fiber counts using such practices. Other recommended provisions simply do not reduce a still significant risk. For example, requiring very low clearance samples (analyzed by transmission electron microscopy) to deregulate all "regulated areas" to assure that EPA/AHERA level of 0.01 f/cc is met does not appear to be necessary to reduce a significant risk to employees. There is an extremely low (although speculative) risk of asbestos related disease estimated at such clearance levels, and, there is evidence that immediate clearance sampling does not predict later concentration levels.

OSHA discusses the recommendations made by participants in the preamble sections which cover the recommended provisions. The following is a list of the major recommendations made by public which are discussed later:

1. Recommendations for a mandatory building inspection program:

Recommended by BCTD (Ex. 143, Att. A); Gobbell Hays Partners, Inc. (7- 149), Service Employees International Union (SEIU) (Ex. 144); American Federation of State, County and Municipal Employees, (AFSCME, Ex. 141); ORC, or assume it is asbestos (Ex. 145), SBA, limited to employers whose work duties involve contact with ACM shall assure that all ACM in workplace is identified, need not inspect building areas constructed since 1980.

2. Mandatory notification to OSHA by employers of all removal, renovation, and abatement work: Recommended by BCTD, (Ex. 143, Att. A at 3), The Courdith-Roberts Group, (L7-185); Gobbell Hays Partners, Inc. (7-149).

3. Mandatory use of negative pressure enclosures in regulated areas, except for small-scale, short-duration operations and other limited circumstances: Recommended by BCTD, (Ex. 143 Att A at 5).

4. Mandatory procedures for deregulating regulated areas including mandatory clearance sampling. Recommended by BCTD, (Ex. 143, Att. A at 6); AFSCME (Ex. 141).

5. OSHA accreditation of training and OSHA designated detailed training curricula. Recommended by BCTD (Ex. 143 Att. A at 8) 6. Reduction of PEL below 0.1 f/c. Recommended by Gobbell Hays Partners, Inc. (Ex. 7-149).

7. Require that required protective clothing be impervious. Recommended by Melco, Inc. (L7-187), J.Loften, Asbestos Workers Local Union #16 (Ex. 137).

8. Specific training for maintenance and custodial workers in buildings that contain asbestos-containing material. Recommended by SEIU. (Ex. 144 at 14).

9. Requirement that building owner respond to knowledge of asbestos in building by establishing O&M plan. Recommended by SEIU (Ex. 144 at 17); AFSCME, (Ex. 141).

10. Change in medical surveillance requirements for maintenance and custodial workers in ACM buildings -- they exceed the 30 day limit. Recommended by AFSCME, (Ex. 141).

11. Reduce action level to 0.05 f/cc. Recommended by BCTD. (Ex. 143).

12. Reduce STEL to 0.5 f/cc over 30 minutes. Recommended by BCTD. (Ex.143), also by SESAC and NIOSH (Ex. 7-77, 125).

13. Require most effective respirators feasible in all asbestos work. Recommended by BCTD. (Ex. 143).

14. Require more specific and protective brake repair procedures. Recommended by Clayton Associates, Inc. (Ex. 148).

15. Regulate activities involving "friable" asbestos-containing material differently from those involving "non-friable" asbestos. Recommended by Edison Electric Institute, (Ex. 7-145 , at e.g., 8 for quantity cut-offs for SSSD activities.) 16. A clearance fiber level of 0.04 f/cc was recommended by SESAC who stated that such a requirement was needed to "ensure that the asbestos work area is safe to enter by unprotected personnel after the asbestos work operation is completed." (Ex. 7-77).

Relationship to Indoor Air Quality Proposed Rule

On April 5, 1994 at 59 FR 15968, OSHA proposed a new standard for indoor air quality. The proposed regulation included a clause making brief reference to asbestos. See Paragraph (d)(8) at page 16036. That reference was unintended as OSHA, intends to cover all asbestos issues in the final asbestos rule where full consideration has been given to them. OSHA will not create new requirements in a final Indoor Air Quality Standard that are specifically designed to control asbestos exposures, and will announce that it is withdrawing the asbestos clause in paragraph (d)(8) at the commencement of the indoor air hearing. Accordingly there is no need for parties to submit asbestos-related materials into the Indoor Air record.

III. Summary and Explanation of Revised Standards

These final standards constitute OSHA's response to the remaining issues raised for the Agency's reconsideration by the United States Court of Appeals for the D.C. Circuit. The specific issues raised by the Court are: the establishment of operation-specific permissible exposure limits; the extension of reporting and information transfer requirements; the expansion of the competent person requirement to all employers engaged in any kind of construction work; and, the clarification of the small scale, short duration operation exemption from the requirement to establish a negative-pressure enclosure. For convenience OSHA is summarizing here its response to each of these issues. They are discussed in depth below. Also discussed below are the other changes OSHA has made which are not in direct response to the remand.

Issue 7. "Establishment of Operation Specific Exposure Limits": The court remand causes OSHA to consider establishing operation-specific permissible exposure limits to the extent feasible, as needed to eliminate significant risk of illnesses caused by asbestos exposure. OSHA proposed to decrease the PEL to a uniform 0.1 f/cc. OSHA believes that this limit is feasible for most industry sectors to reach most of the time (55 FR 29720). However, OSHA explained that PELs lower than 0.1 f/cc are difficult to reliably measure. However OSHA has followed a more effective approach to lowering exposures for those sections and operations where lower exposures can be achieved. This approach is triggering protective provisions based on the kind of operation undertaken, rather than measured exposure levels. This approach is consistent with some other health standards (e.g., lead, coke ovens).

A major reason for this approach for construction and shipyards is that measured levels of exposure often fail to define risk and are often not received before the work is completed. This was partly explained in the proposal. There OSHA noted that for removal jobs, highly variable amounts of asbestos are generated, "reducing the predictability of exposure levels from one monitoring event to the next. Moreover, measured asbestos levels often cannot be used to determine the need for (specific controls) . . . because of the time required by the laboratory to complete the test and report the results." (55 FR at 29715-16). Thus, it would be unproductive to leave employees unprotected while initial monitoring results are being analyzed; and in many cases, even prompt reporting of exposure levels during the setting up of the controls would not predict exposures during the actual removal.

A significant risk remains at the PEL of 0.1 f/cc, and it is feasible to attain lower levels for some workers exposed to asbestos. OSHA has therefore considered whether to establish different PELs for different operations based on the lowest exposure limits that can feasibly be achieved in those operations and that are needed to eliminate significant risk. OSHA has decided not to do so because the operation-specific work practices mandated in the standard will be a most cost-effective means of assuring that significant risk is eliminated to the extent feasible.

Asbestos has been the subject of extensive rulemaking by OSHA and other agencies, and the operations that expose employees to asbestos are well known and thoroughly studied. Moreover, given the shift away from asbestos products wherever substitutes are available, it appears unlikely that major new uses will be found for asbestos in the future. OSHA has therefore been able to focus its rulemaking effort on evaluating the work practices that will best reduce asbestos exposures in the specific operations that expose workers to asbestos. The result is a standard that relies heavily on mandated work practices that will, in most situations, result in employee exposure well below the PEL. In effect, the mandated work practices will assure that each asbestos worker is exposed to the lowest feasible level for the operation in which that worker is engaged. This approach was taken in the 1986 construction standard. There, OSHA "tiered" its construction standard "to apply increasingly stringent requirements to those work operations associated with the highest exposures." (51 FR at 23706). Rather than two classifications as in 1986 (small-scale and abatement work), OSHA now divides construction work into four classes and has made additional limited distinctions based on measurable variables such as amount of material disturbed.

Since OSHA's approach assures that each employee is exposed to the lowest feasible level of asbestos, no additional protection would be gained by establishing a series of different PELs for different operations. Such an approach would add cost and complexity to employers' compliance duties and to OSHA's enforcement duties without benefiting worker health. PELs lower than 0.1 f/cc would be particularly unsuitable as compliance criteria because it is difficult to reliably measure lower levels. Because such measurements are unreliable, if lower PELs were established, measurements taken by employers and by OSHA would provide an uncertain basis for determining whether employers have fulfilled their compliance duties. However, both employers and OSHA can easily determine whether the work practices prescribed in the standard are being followed. The mandated work practices thus assure that employees are better protected than a series of different PELs while reducing compliance burdens on employers and easing the agency's enforcement burden. Therefore, rather than set operation-specific permissible exposure limits, OSHA proposed to further reduce risk by requiring certain additional work practices. The operations for which mandatory work practices are required would otherwise result in employee exposure that is significant. OSHA believes that these controls are feasible, reasonable, and necessary.

OSHA also proposed, in the general industry standard, to link the dates when engineering controls would be required to reach the new lower PEL with the EPA Ban and Phase-out Rule. This linkage is no longer an option since the Fifth Circuit Court of Appeals recently vacated the ban and it is not yet clear which asbestos-containing products will no longer remain in commerce, and staged phase-outs of asbestos containing products are not required.

Issue 3. "Small Scale Short Duration Definition": The Court asked that OSHA clarify the exemption for "small scale, short duration operations" from the negative-pressure enclosure (NPE) requirements of the construction standard. The negative pressure enclosure requirements are a substantial set of requirements. They include creating a system of regulated areas with a sealed work area under negative pressure, decontamination facilities and procedures, clean room facilities and procedures and shower facilities, and other practices to reduce worker exposure and spread of contamination outside the work area. In that standard, NPEs were required for all removal, demolition and renovation work except for small scale short duration operations.

The Court suggested, based on its view of the Agency's earlier intent, that OSHA limit the exemption to work operations where it is impractical to construct an enclosure because of the configuration of the work environment. In an earlier response to the remand order, published in the Federal Register (54 FR 52024, December 20, 1989), OSHA declined to amend the regulatory text on the small-scale, short duration issue, without conducting supplemental notice and comment rulemaking. The Agency explained "that explicitly limiting the exemption to situations where negative pressure enclosures are impractical might not reduce employee risk from asbestos exposure." (54 FR at 52026). OSHA stated that in the supplemental rulemaking, it intended "to discuss the effectiveness and drawbacks of negative-pressure enclosure, glove bags, and alternative control systems; and to specify more clearly under what circumstances various control systems may be used." (54 FR at 5207). OSHA also noted that the small-scale, short duration issue is related to the scope of the "competent person" requirement, which the 1986 standard lifted for operations which conformed to the exception, and thus combined consideration of both issues would be appropriate.

Accordingly, in July 1990, OSHA proposed related changes in both provisions "small scale, short duration" operations would be redefined in terms of general criteria, as well as the 1986 approach of listing specific examples. However, the underlying premise remained the same as in the 1986 standard: i.e. exemptions to the negative-pressure enclosure requirement for removal, renovation and demolition projects and limited to jobs which conformed to specified criteria. "Competent" persons, according to the 1990 proposal, were to be required as supervisors on all asbestos-related construction worksites, instead of as in the 1986 standard, that required competent persons only for non "small-scale, short term jobs." Required training for competent persons, would vary, however, depending on the kind of asbestos-related job needing supervision.

The final provisions resolving these issues, are different from the proposal. Four classes of increasingly hazardous types of construction activity are matched with increasingly stringent control requirements. Class I asbestos work means activities involving the removal of asbestos containing material (ACM) and presumed asbestos containing material (PACM) which is "high risk." Class II asbestos work means activities involving the removal of ACM and PACM which is not "high risk." Class III asbestos work means activities involving repair and maintenance where ACM and PACM is disturbed. Class IV asbestos work means maintenance and custodial activities during which employees contact ACM and PACM and activities to clean up waste and debris containing ACM and PACM. Each class includes work with similar exposure levels and with similar exposure risks. Each has a prescribed set of controls and work practices. Basically only Class I work, high-risk activities, require negative-pressure enclosures. The standard allows other designated proven control systems in limited circumstances and provides for yet-to-be-developed systems if certain backstop provisions are met. As indicated in its earlier responses to the Court, and its public notices of proposed rulemaking, OSHA has evaluated available control technologies and has concluded that the use of negative- pressure control enclosures should be regulated in terms of when they are required rather than when they are not.

In a major departure from the language of both the 1986 standard and the proposal, OSHA is deleting the term "small scale, short duration" from the regulatory text. Instead, the agency is distinguishing high- from lower-risk operations through the use of the classification system described above. Work that was exempted from the negative pressure enclosure requirements in the existing standard because it was of "small-scale, short-duration" are considered to be Class II and Class III work in this amendment. The agency finds that the term "small-scale, short term" is too limiting, is confusing, and cannot be defined with sufficient precision to serve the purpose of distinguishing high risk asbestos-disturbing activity from activity of reduced risk.

The term is limiting because it focuses on a fraction of the circumstances and criteria which define lower risk work with asbestos- containing material. For example, removing asbestos-containing products like transite panels, likely will not result in significant exposure, even if conducted for more than one day, if there is use of a few simple controls. As much as the scope and duration of the job, the materials themselves, their condition and the work-practices used define hazard potential. OSHA had tried to include these concepts under the "small-term, short-duration" exception in the current standard, by reference to examples. However, the breadth of the examples led the court to observe that "the exception as now worded seems to erase the rule." (838 F. 2d at 1279).

In the 1990 proposal OSHA tried to identify the conditions and operations which separated higher risk work with ACM from lower risk work in its small-scale, short-term definition. Still anchoring the distinction however, was OSHA's belief that the time a job took, and the amount of material involved, primarily determined risk. Based on the record of this proceeding, OSHA now finds that these are relevant, but not exclusive, factors.

OSHA finds also that use of the term is confusing. In 1986, in its list of activities considered "small-scale, short-term," OSHA listed some which are neither small-scale or short-term, but were regarded as lower risk, such as roofing work. To cure this confusion, OSHA proposed, in 1990 to limit the "small-scale, short duration" exemption to a subset of renovation, removal and demolition operations which took less time, and/or involved small areas. Even for these activities a temporal or volume cutoff was difficult to define, and the proposed definition contained numerical criteria, which varied depending on which activity was defined. In addition, it proposed to exempt other activities, such as roofing, regardless of the size of the project, from the negative-pressure enclosure requirement. EPA uses the term "small-scale, short-duration" to describe cut-offs which are much higher than those proposed by OSHA for its reporting requirements for asbestos renovation, demolition and removal work under NESHAPS. And under EPA's worker protection rule which applied to state and local government workers in OSHA non-state plan states, reporting requirements for asbestos "abatement" projects, do not apply to projects involving "less than 3 linear feet or 3 square feet of friable asbestos material." (40 CFR 763.124).

Many objections to the proposed definition were received by the Agency. After reviewing this record, and in light of the variety of interpretations of the term "small-scale, short-duration," OSHA determined that it is inappropriate to use that term as the equivalent of lower risk activities. Once OSHA decided to include other control methods in the "preferred category" for high risk asbestos work, neither a "small-scale, short-duration" definition nor an exemption from negative-pressure enclosure requirement was central to OSHA's regulatory scheme. As explained more fully below, although OSHA no longer uses the term "small -- scale, short-term" to exempt activities from universal requirements, OSHA uses the related terms "small-scale" and "reduced exposure potential" as part of a larger classification scheme.

Issue 8. "The extension of reporting and information and transfer requirements":

A. Notification to OSHA

OSHA had proposed expanded notification and reporting provisions in response to the Court's remand order concerning two issues. The first is whether OSHA should require employers to give the Agency advance notification of asbestos-related jobs. BCTD, in the 1984 rulemaking had suggested that OSHA should require all construction industry employers to file reports concerning any building demolition, renovation or removal project involving asbestos prior to beginning such a project. Two health enhancing benefits of a notice requirement were advanced by BCTD. One, is the help such information would provide the Agency in targeting inspections. The other is a claimed reduction in risk because of the consciousness-raising and self-education provided by the notice process.

The Court noted that the BCTD proposal would "arguably generate better information for "selecting targets for inspection and that it was based on "uncontradicted (and unanalyzed) evidence of non-de minimis benefits." (relating to compliance enhancement). (838 F.2d at 1278). It remanded the issue to the Agency for further explanation or rebuttal.

OSHA responded in 1990, by proposing a new provision to require employers to notify OSHA in writing prior to engaging in demolition, renovation, and removal operations which are not small-scale, short-term operations. OSHA's proposed notice requirement shared many core elements with EPA's then current and proposed notification requirements under NESHAPS. OSHA noted that "(t)he proposed notification is modeled after the notification requirement concerning asbestos abatement projects that occur in conjunction with building demolition and renovation operations. OSHA noted further that "(e)mployers can satisfy the OSHA (proposed) notification requirement simply by forwarding a copy of the EPA form to the OSHA area office when complying with EPA's asbestos NESHAP." (55 FR at 29731). Both EPA's and OSHA's proposed, notification requirements would exempt less extensive operations. In OSHA's case, the exemption would have applied to small-scale, short-duration operations as otherwise defined in the standard. EPA's cutoffs are annual amounts: 260 linear feet on pipes and 160 square feet on other facility components. OSHA noted that many asbestos jobs would meet the notification requirements of both agencies, however there would be an indeterminate, yet significant number for which EPA notification would not be called for, but OSHA's proposed requirement would apply.

Most public comment opposed the requirement. The major objection was the burden on the employer from completing and mailing the notification form. Further, some commenters questioned the overall usefulness of the notification requirement in promoting compliance (See comments of Shipbuilder's Council of America Ex. 7-2.) BCTD continued to argue for extensive reporting requirements for the reasons stated above. A few other commenters supported its position. (Ex. 7-5, 7-6, 7-34, 7-64, 7-95, 7-118, 7-132, 7-149, 141, 144).

OSHA has carefully reviewed all the comments. Based on the review and subsequent developments, the final regulation scales down OSHA's proposed notice requirements. OSHA is now requiring advance notification of Class I (mainly large-scale removals) only when the employer intends to utilize controls other than a negative pressure enclosure which meets the requirements of paragraph (g) of this standard, and in some circumstances, where modifications of glove bag systems, glove box systems and other control systems described in paragraph (g) are made.

There are a number of reasons for OSHA's decisions. OSHA believes that the potential benefits in direct risk reduction from a separate OSHA reporting requirement are unlikely. There are already extensive EPA and state reporting requirements which OSHA requirements would partly duplicate. The EPA and state requirements already create any incentive to comply that such reports could create. Similar OSHA reports would not increase this benefit. Information which may be useful to OSHA in targeting inspections can be retrieved by information-sharing with the EPA while avoiding overlapping reports. OSHA notes that the Paperwork Reduction Act requires that federal agencies avoid clearly duplicative reporting requirements. Various comments challenge the value of duplicative requirements (e.g., Ex. 7-17, 7-20, 7-22, 7-28, 7-39, 7-46, 7-47, 7-50, 7-54, 7-72, 7-74, 7-76, 7-77, 7-78, 7-79, 7-81, 7-86, 7-87, 7-88, 7-89, 7-102, 7-103, 7-108, 7-112, 7-125, 7-133, 142, 147). Thus, although OSHA's and EPA's reporting requirements are only partially duplicative, these considerations have influenced OSHA's decision not to require extensive pre-job reporting. OSHA is concerned that in reviewing the volume of reports which may be spawned by a separate OSHA requirement which exceeded the EPA requirements would strain OSHA area offices enforcement resources and drain such resources from other enforcement efforts. However, OSHA finds that advance reporting is appropriate where information is related to new or modified control methods for Class I work. In such cases, heightened attention to the data supporting their use will result from the requirement to send them to OSHA.

BCTD's contrary view that compliance would be enhanced was based in part on its contractor's report, submitted after the 1984 hearing. The report estimated that an advance reporting requirement would reduce "the number of workers with TWA exposures over 0.1 f/cc" up to 30% in drywall removal and demolition, and lesser amounts in other construction work. These estimates were based on the opinions of a seven person "focus group" which included three representatives of member unions of BCTD. No methodology was presented for deriving these quantitative estimates, and no supporting data has been submitted in either rulemaking (see brief Ex. 143 at 198). The Court referred to the report in its decision as uncontradicted, but that was because it was submitted late in the rulemaking procedures.

The Agency believes based on its experience that these estimates of specific quantifiable benefits are speculative. But more importantly, the now-existing EPA and state reporting requirements and OSHA's use of that data for targeting inspections will achieve those benefits without duplicative reporting requirements. Further, OSHA made various changes to the final standard which will also achieve some of these benefits. These include the expanded provisions on hazard communication, which will alert employees in all asbestos renovation, removal and maintenance work that presumed asbestos containing material is present; that require competent persons to evaluate the work site before work is begun, by informing employers that OSHA is setting up information sharing systems with EPA to access employer notices sent to that Agency, and that require employers who use new and modified control systems to notify OSHA.

Help for OSHA in targeting inspections from the submission of advance reports is the other claimed benefit from a reporting requirement. Some participants claimed that because pre-job reporting was helpful to EPA in targeting its inspections for compliance with NESHAP requirements, an OSHA pre-job reporting would similarly benefit this Agency. EPA did not testify at the hearing, but available information shows that its reporting system provides useful information to that Agency's enforcement program. NESHAPS reporting is made mostly to 45 state agencies, delegated by EPA to implement the asbestos NESHAP. Reporting in EPA Region II, is directly to the Regional Office. These reports are the source of two data bases: the National Asbestos Registry System (NARS), which develops a historical record of asbestos contractors, updated quarterly: and the ACTS system, which is a local data base on the compliance history of each contractor. OSHA is informed that ACTS is a tool that delegated agencies may use for day-to-day tracking of asbestos activities. EPA's evaluation of the reports submitted to it and other information used in its NESHAP enforcement effort constitute a valuable resource for OSHA.

In 1991 both agencies signed a Memorandum of Understanding (MOU) to share information which will aid their enforcement efforts. Pursuant to that MOU, OSHA is developing with EPA an information sharing system based on the reports submitted both to EPA and to various states upon delegation from EPA to access that information to help OSHA target asbestos removal jobs. OSHA also believes that at this time some EPA delegated states, and OSHA state plan states have worked out ways to share notifications. OSHA believes that utilizing the EPA data to assist in targeting inspections will be more effective than duplicative reporting requirements.

The Agency believes, based on its own enforcement experience that a limited notification requirement may enhance compliance in specified circumstances. Employers who choose to use new or modified control technology to reduce exposures in Class I asbestos work, must notify OSHA in advance, using EPA's NESHAP reporting form. Such information about new and/or modified asbestos control technology submitted to OSHA by employers who wish to use it will provide accessible information for the Agency to use to evaluate such technologies. OSHA believes that requiring employers to routinely submit to the Agency their data in support of claims of the effectiveness of new technology will help OSHA, employers and employees and their representatives to evaluate its effectiveness promptly.

Shipyard Employment Standard

One area of the proposed standard to which SESAC raised objection was the requirement that OSHA be notified 10 days prior to initiating work on large scale asbestos operations. In addition to reiterating many of the objections to the provision raised by others, they pointed out that often they must immediately work on ships which enter their shipyards and turn them around quickly and that the delay caused by the notification would be overly burdensome. As OSHA explained above, notification of OSHA is required only when Class I operations are undertaken and alternate methods of control, other than the negative-pressure enclosure methodology, is to be employed. This provision applies both in the construction and shipyard employment standards.

B. Notification of Other Employers and Subsequent Owners

The Court remanded the issue of whether OSHA should, as recommended by BCTD, require employers contracting asbestos-related work to establish, maintain and transfer to building owners written records of the presence and locations of asbestos or asbestos products, in order to facilitate identification and prevention of asbestos hazards. As noted in the 1990 remand proposal, the Court remanded this issue so that the Agency may reach "its own judgment on the issue" of whether it was legally empowered to adopt such a requirement (See BCTD v. Brock, supra at 1278). OSHA concludes that BCTD has made a persuasive case for the need to expand the notification provisions to other employer and building owners and from them to subsequent employers with exposed employees. This is a necessary way to informing subsequent employers that their employees are at risk of asbestos exposure and of the need to take appropriate precautions. Requiring building owners to maintain and provide this information is by far the most effective way of notifying employers of exposed employees who are doing work many years after the asbestos was identified.

OSHA has developed an information transfer scheme concerning the presence of asbestos in buildings and structures which may present a hazard to employees which is more comprehensive than the recommendation of BCTD. The approach places the primary compliance burden on the building and/or facility owner, even though the employees at risk may not be the owner's direct employees. Thus, this final standard confirms OSHA's tentative view in the proposal, that it has authority to require building owners who are statutory employers to take necessary and appropriate remedial action such as notifying other employers, to protect employees other than their own (see 55 FR at 29729).

The proposed hazard communication provision limited the building owner's communication obligations to "available" information concerning the presence and location of asbestos. Now, in the final standard, the building owner must communicate his knowledge of the presence and location of ACM, based on "available" information, and, new to the final standard, of the presence and location of certain high risk materials, which are presumed to contain asbestos (PACM), unless the building was constructed or renovated after 1979 or is rebutted using laboratory analysis. Further details of this provision are spelled out later in this preamble.

Issue 9. "Competent Person". The Court remanded to OSHA to determine whether employers engaged in any kind of asbestos related construction work should be required to designate "competent persons" to oversee safety measures, or whether, as in the 1986 standard, employers should only be required to designate trained "competent persons" for asbestos removal, demolition, and renovations operations that are not small-scale, short duration. The court requested that OSHA either expand the "competent person" requirement or provide a more persuasive explanation of its refusal to do so.

OSHA proposed in 1990 to expand the requirement. Under the proposal, supervision of all asbestos construction worksites by a "competent person" would be required; the training of a competent person would be keyed to the kind of asbestos operation. However, the proposal left undecided whether onsite, continuous supervision of all asbestos-related work would be required for all asbestos work. The final standard resolves these issues. A "competent" person, as defined in the general construction standards, must supervise all work under the asbestos construction standard. That person must be "capable of identifying existing asbestos * * * hazards in the workplace, and has the authority to take prompt corrective measures to eliminate them * * *" 29 CFR 1926.58[b].

OSHA reiterates its statement in the proposal that "all construction site employees would benefit from the presence of a competent person to oversee asbestos-related work" (55 FR at 29726). However, the need for on-site supervision varies with the hazard potential of the work undertaken. All workers performing Class I construction work must have continuous access to an on-site supervisor, who meets the training requirements for designation as a "competent person" under this standard. Supervision for Class II and III work does not always require a continuous on-site "competent person," therefore the standard requires inspections at "sufficient" intervals and at employee request. Supervision of installation of asbestos containing construction materials and Class IV work must also be accomplished by complying with the "generic" requirement for "frequent and regular" inspection [Paragraph (0)(2)].

Training for "competent persons" can be accomplished in a number of ways and meet the standard's performance requirements. For Class I, II and III work, the "competent person" must take a course such as a course under the EPA Model Accreditation Plan for accredited contractor/supervisor, project designer or management planner course, or their equivalent in content, duration, and criteria for success. Class IV work may be part of larger construction projects, in which case the competent person trained to supervise the project should supervise the on-site cleanup activities which constitute the Class IV work.

Explanation of Provisions of the Final Standards

The following is a provision-by-provision discussion of the revised asbestos standards. Thus all the provisions in all three standards: general industry, construction and shipyard employment, relating to a topic will be discussed under the heading for that topic. For example, under the scope heading, the scope of the general industry standard will be first discussed, then the scope of the construction standard, and finally the scope of the shipyard employment standard. Similarly, under the methods of compliance heading, the provisions in each standard relating to that topic will be discussed. Where a discussion applies to all three or to two of the separate standards it will be so noted and will not be repeated for each standard. OSHA believes that this format will help the public understand where and why the various standards contain different provisions relating to the same subject matter. Further, it will avoid repetition in explanations where a common policy rationale applies to more than one asbestos standard.

(1) Scope and Application

Paragraph (a). General Industry Standard. 29 CFR 1910.1001. The general industry standard covers all activities (except agriculture), covered by the Act which are not otherwise covered by the construction asbestos standard, 29 CFR 1926.1101, and the new shipyard employment standard, 29 CFR 1915.1001. Consequently, marine terminals and longshoring would be covered by the general industry standard if asbestos were being loaded, unloaded or stored. The asbestos construction standard, in existence since 1986, lists activities which it covers. This includes construction activities though they may take place at a factory or agricultural premises. The new shipyard employment standard, likewise lists its covered activities.

Formerly, the general industry standard had been considered the generic asbestos standard. However, because of dramatic changes in the market for asbestos containing products, the standard now covers only four industry segments, three of which are distinct from each other, and all are diminishing in volume and employee population. Brake and clutch repair is the activity engaged in by the largest group of asbestos exposed workers, although most of them are exposed sporadically and at low levels. Next largest is custodial workers who do not perform their duties as part of construction activities, but clean surfaces, sweep, buff and vacuum floors and wash walls and windows in manufacturing plants and a wide variety of public and commercial buildings. Although in the preamble to the proposal and throughout this proceeding OSHA and most commenters had treated these workers as part of the construction work force, OSHA concludes that pure custodial work is not a construction activity, and should be regulated under the general industry standard. However, to avoid misinterpretation or for purposes of clarity of duties to affected parties, OSHA also is including provisions protecting custodial workers who may unknowingly contact asbestos-containing material in the construction and shipyard employment standards. In this way, there will be no advantage to interpreting coverage under any one of the asbestos standards, rather than another.

The primary and secondary manufacture of asbestos containing products, completes the roster of identifiable general industry sectors. Once, along with installers of asbestos-containing products, the core of the asbestos-exposed work force, asbestos-containing product manufacturing employees are rapidly dwindling in number. OSHA expands on this theme its on economic analysis later in this document. At the time of the proposal, EPA had prohibited, at three stated intervals from August 1990 to August 1996, the future manufacture, importation, processing and distribution in commerce of asbestos in almost all products (54 FR at 29460, July 12, 1989). Subsequently the ban was overturned by the United States Court of Appeals for the Fifth Circuit. EPA has interpreted the decision as invalidating only those portions of the ban for products that were manufactured or imported at the time of the decision. Despite the remaining legitimacy of manufacture and use of asbestos-containing products, the industries which make and maintain them and the employees who are employed in those industries are declining rapidly and dramatically.

Paragraph (a) Construction Standard. 29 CFR 1926.1101. The construction standard covers (but is not limited to) the following activities involving asbestos: demolition, removal, alteration, repair, maintenance, installation, clean-up, transportation, disposal, and storage. It has been redesignated 29 CFR 1926.1101 to reflect the reorganization of health standards covering construction made June 30, 1993 (58 FR 35076). The scope and application remain generally unchanged from the proposal and earlier standard. However, 3 issues arose. First, new language, proposed in 1990 is retained in the final. "* * * coverage under this standard shall be based on the nature of the work operation involving asbestos exposure, not on the primary activity of the employer." This point was made clearly in the preamble to the 1986 standards; however, it was not specifically stated in the regulatory text and subsequently some confusion arose among the regulated community. Therefore, it is included as a clarification of the intended application of the standards. Asbestos work which involves removal, repair, maintenance or demolition is therefore explicitly regulated by the construction standard even if such work is performed within a facility otherwise regulated under the general industry standard.

Certain commenters stated that maintenance and custodial work should not be regulated by the construction standard, because they are not construction operations. OSHA notes that it has made a distinction between maintenance and custodial work, that maintenance work is covered in the construction and shipyard employment standards, and that custodial work is covered in all three standards, when it is incidental to work otherwise covered by a standard.

"Naturally Occurring Asbestos in Soil": Prior to the publication of the 1990 asbestos proposal, OSHA received submissions describing asbestos deposits which occur as natural formations in the U.S. and that when disturbed, for example during earthmoving projects or during mining operations, drilling, blasting or sawing operations, the asbestos in the deposit can become airborne and expose workers to significant levels of asbestos fibers (Ex. 3-10, 3-11). The Agency proposed to clarify that such activities were covered under its asbestos construction standard and that methods of control were to be employed to avoid worker exposure during disturbances of naturally occurring asbestos deposits. OSHA sought additional information regarding any additional provisions it would adopt to protect workers engaged in these activities. In the proposal, the Agency also requested any information on appropriate methods to use to determine the presence of asbestos in soils, the effectiveness of wet and/or other methods to control worker exposures and information on effective decontamination methods for exposed workers.

There were relatively few comments received on this issue. Some felt that asbestos in soil resulted in negligible exposures and that wetting to prevent fugitive emissions during earth moving would be sufficient control (e.g., Ex. 7-6). Another participant said there was a lack of control technology and called for further study to determine the extent and location of problems (Ex. 7-63). The industrial hygienists who had raised the issue of worker exposure to naturally occurring asbestos, described the occurrence of asbestos in the soil of Fairfax County, Virginia (Ex. 7-143). They reported that water misting during disturbance of asbestos-containing soils was effective in controlling exposures. They recommended the use of negative pressure air purifying respirators, protective clothing and showers to control exposures.

OSHA finds that the record indicates that certain construction sites in mostly well-defined areas contain deposits of naturally occurring asbestos. In such areas, airborne asbestos during earthmoving activities may result in significant exposures. In such cases, wetting of the excavation site, often required by local authorities, should be sufficient to suppress measurable airborne asbestos concentrations. Information regarding the presence of asbestos in the vicinity of construction sites may be available from state environmental agencies, the United States Geological Survey, and the Bureau of Mines.

In the absence of information which is readily available showing asbestos contamination of soil in the immediate vicinity of a construction site, the employer is not required to take any action under this standard.

Paragraph (a) Shipyard Employment Asbestos Standard. 29 CFR 1915.1001.:

Workers engaged in shipyard industry activities, i.e. shipbuilding, ship repair, and other work in shipyards, who are exposed to asbestos have been protected by inclusion in 1986 general industry and construction standards published in 1986. Like in other non-construction industries, OSHA intended employees working in shipyards to be protected by the general industry standard, except for those operations which were specifically listed as covered by the construction standard, i.e. renovation, removal, demolition and repair.

In 1988, OSHA convened the Shipyard Employment Standards Advisory Committee (SESAC), comprised of members from labor, private industry, state and federal government, and professional and trade associations. The Committee's charter directed it "to develop a single set of comprehensive health and safety standards for Shipyards."

In the 1990 NPRM, OSHA sought information and comment on how best to provide equivalent protection to workers engaged in shipyard activities. The Agency noted that although it had considered these operations to be regulated under the general industry standard in the 1986 rulemaking, subsequent considerations led OSHA to observe that many shipyard industry activities are construction-like in nature.

In response, SESAC drafted alternative regulatory text which it submitted to this rulemaking docket with the recommendation that it be adopted as a vertical asbestos standard for shipyards (29 CFR 1915, Ex. 7-77). The Committee stated: "Maritime is neither general industry nor construction -- it is maritime. "This committee was formed by the Secretary of Labor with the objective in its charter to "recommend * * * one comprehensive set of standards* * *for the shipbuilding, ship repair and shipbreaking industries* * *" (Advisory Committee Charter).

Additional comment and testimony on this issue was submitted during the rulemaking. For example, Charles Sledge, Jr. of the Norfolk Naval Shipyard in his testimony stated that he did not feel that shipyard industry work meets the definition of construction work defined in 29 CFR 1910.12 (Ex. 28). Although he preferred keeping shipyard industry operations under the general industry asbestos standard, he recommended that OSHA apply the SESAC-recommended standard to shipyard activities rather than the construction asbestos standard. He pointed out that most asbestos work in shipyards takes place in fixed locations and does not have the transient nature of true construction work. Mr. Sledge also felt that shipyards have developed ways to stay below the PEL and that any change would result in requiring expensive alterations of facilities, and a need for additional training.

Several commentors including F. Losey of the Shipbuilders Council of America (Ex. 7-2), D. Knecht of Litton Ingalls Shipbuilding (Ex. 7-22), and C. Klein of Newport News Shipbuilding (Ex. 7-71) encouraged OSHA to adopt the SESAC-recommended regulatory text for shipyards (Ex. 7-2).

J. Collins of Naval Operations objected to OSHA's proposal to apply the construction asbestos standard to shipyard industry because he considered some of the provisions infeasible on vessels (Ex. 7-52). In his opinion the construction standard requires showers be located at the entrance to the regulated area and that this was not reasonable on small ships like submarines. Other comments, (apparently by others) in this submission expressed the view that shipyard industry activities should be regulated under the construction standard since they are often identical to construction work. To the same effect see Ex. 7-52.

BCTD stated in its testimony that:

* * * [It] agrees with OSHA that, because the manner in which maritime employees work with and are exposed to asbestos is similar to the experience of construction employees, the provisions of the construction standard should apply in that industry. In particular, whenever the likelihood exists that asbestos-containing materials will be disturbed in ship repair and renovation, that activity should be conducted under a negative air apparatus. [Ex. 34, p.2]

The rulemaking process revealed that there was confusion in the shipyard industry sector as to which of the standards applied to the various activities within the shipyard. In his testimony, the Chairman of the Shipyard Employment Standards Committee said: "In the case of asbestos, both 1910 and 1926 are both applied in various shipyard operations. This is confusing to the shipyard work force who are required to follow one set of rules one day and another set the next day." (Tr. 337) In the current revision of the asbestos standards, OSHA has determined that a separate vertical standard for shipyards is appropriate. OSHA understands that many spokespeople for the shipyard industry believe that compliance with OSHA's asbestos standards will be facilitated in shipyards if only one standard applies to those workplaces. Because OSHA wishes to promote compliance, and because the Agency acknowledges that some shipyard conditions are unique, OSHA is issuing a standard that will apply only to shipyard industries. It is neither less nor more rigorous than the general industry and construction standards. How it differs from the two other asbestos standards will be discussed under the topic heading for each substantive provision, in the preamble text which follows. The recommendations will be discussed more fully, following a summary of the relatively small number of comments received by the Agency.

Most provisions in the final shipyard standard include some relevant provisions similar to the revised construction standard. In addition OSHA has incorporated some of the specific recommendations made by the Shipyards Employment Standards Advisory Committee discussed below.

Relatedly, the Great Lakes Carriers Associates, representing fleets on the Great Lakes, wanted assurance that asbestos exposures of seamen aboard vessels will continue to be regulated by the Coast Guard under an existing Memorandum of Understanding between the Coast Guard and OSHA (Ex. 7-8). OSHA does not intend to alter the agreement it has with the Coast Guard. Rather, the maritime standard under discussion concerns shipbuilding, ship repair and ship-breaking activities (29 CFR part 1915, Shipyards).

(2) Definitions

Paragraph (b) General Industry, Construction and Shipyard Employment. OSHA has deleted some definitions which appear in the 1986 standards, and has added others. Alphabetically, the changes are as follows:

The 1986 standards contained an "action level" of 0.1 f/cc, one half the PEL of 0.2 f/cc. The action level provides a "trigger" for certain duties, such as monitoring, medical surveillance and training. The Court of Appeals for the District of Columbia Circuit instructed OSHA to consider reducing the action level to 0.05 f/cc should the PEL be reduced to 0.1 f/cc. In most single-substance air contaminant standards it has issued, OSHA has set an action level equal to half the PEL. The action level triggers duties of monitoring, medical surveillance, and training, and assures that workers who are not exposed at or above the PEL but who may nevertheless be exposed to levels that present a risk to their health receive a degree of protection. The action level thus helps to reduce residual risk that may remain at the PEL.

In these standards, OSHA has taken a different approach to protecting workers exposed to levels of asbestos below the PEL. Instead of a numerical action level, employer duties involving training and medical surveillance are triggered by exposure to ACM or PACM or by the type of work being done. Additionally, work practices also are required regardless of measured exposure levels. OSHA considers this approach to better protect employees than an action level, which triggers training and medical surveillance duties based on monitoring results. OSHA's approach is particularly appropriate for asbestos because in many cases, asbestos levels below the PEL cannot be reliably measured, and duties tied to an action level might therefore be triggered by measurements of dubious accuracy.

In the 1990 proposal, OSHA did not propose an action level based on its tentative conclusion that workplace asbestos concentrations below the PEL could not be reliably and reproducibily measured (55 FR 29722). The Agency asked for comment on the advisability of setting an action level of 0.05 f/cc, and specifically asked whether the methodology for measuring airborne asbestos levels had advanced sufficiently to allow reliable and reproducible measurements at that level. Evidence subsequently submitted to the rulemaking record indicated that levels as low as 0.05 f/cc could not be consistently measured reliably. The rulemaking reinforces OSHA's tentative conclusion that workplace asbestos levels of 0.05 f/cc cannot be measured reliably (see NIOSH Tr. 215, SESAC Tr. 345). Because employers cannot obtain reliable and reproducible measurements of airborne asbestos levels at concentrations of 0.05 f/cc, it would be infeasible to base training and medical surveillance requirements on worker exposure to asbestos at such a level. OSHA therefore declines to establish an action level of 0.05 f/ cc. OSHA recognizes in some circumstances the general advantages of an action level, and if future monitoring technology is developed which would allow reliable, consistent determinations at lower fiber levels, OSHA will reconsider whether an action level would be appropriate for the asbestos standard and whether action under section (6)(b)(7) of the Occupational Safety and Health Act which directs OSHA to "make appropriate modification in the * * * requirements relating to * * * monitoring or measuring * * * as may be warranted by experience, information, or medical or technological developments acquired subsequent to the promulgation of the relevant standard" is appropriate.

The agency has, however, included provisions that require training and medical surveillance of employees exposed below the PEL. Thus, like standards that contain an action level, these standards use training and medical surveillance to reduce the residual significant risk that remains at the PEL. The general industry standard requires that all employees who work in areas where ACM or PACM is present be given a prescribed level of awareness training. The construction and shipyard standards require training of all workers who install asbestos-containing products and all workers who perform Class I, Class II, Class III, and Class IV work. These training requirements assure that all employees who are potentially exposed to more than de minimis concentrations of asbestos can recognize conditions and activities that can lead to asbestos exposure, know of the hazards associated with asbestos exposure, and are trained to utilize the means prescribed by the standard to minimize their exposure.

With respect to medical surveillance, the construction and shipyard standards require medical surveillance of all workers who, for a combined total of 30 days per year or more, engage in Class I, II, or III work, or who are exposed above the PEL or excursion limit. Additionally employees who wear negative pressure respirators are provided with medical surveillance. The general industry standard requires medical surveillance of all workers exposed above the PEL or excursion level, with no 30-day per year limitation. In crafting these provisions, OSHA has attempted to assure that those workers for whom medical surveillance will provide relevant information and benefit are entitled to it. In construction and shipyard work, employees who do not engage in Class I, II, or III work are unlikely to be exposed above 0.05 f/cc (the potential "action level") because the work practices mandated in the standard should result in negligible asbestos exposure to workers who do not specifically engage in asbestos-related work. Employees who engage in only Class IV work also should not be exposed above 0.05 f/cc because of the lower asbestos exposures associated with such work. OSHA therefore believes that the construction and shipyard provisions target medical surveillance where it is needed.

In general industry, the vast majority of workers who are exposed below the PEL will also be exposed below 0.05 f/cc. The work practices mandated for brake and clutch repair, by far the largest general industry segment subject to the standard, should result in virtually all such workers being exposed below 0.05 f/cc. Another large general industry segment, custodial workers, will also be generally exposed below 0.05 f/cc. While some small number of workers in both categories as well as in the manufacturing of asbestos products may be exposed between 0.05 f/cc and 0.10 f/cc on some days, the difficulty of obtaining reliable and reproducible measurements at those levels makes it difficult to identify those workers accurately. Therefore, if medical surveillance were triggered by exposure above 0.05 f/cc, the employees subject to such surveillance would likely be chosen on the basis of the vagaries of the monitoring process rather than on any realistic assessment of the risk that they face. OSHA therefore concludes that it would be infeasible, and would not reduce significant risk, to require medical surveillance for workers in general industry exposed below the PEL or excursion limit.

David Kirby of the Oak Ridge National Laboratory stated his belief that:

I'm not sure if the analytical methodology will be able to support this due to the level of accuracy that's normally associated with trying to take samples under the normal procedures at that level." (Tr. 105)

NIOSH too testified that "[i]n NIOSH's judgment, the establishment of a PEL or an action level below 0.1 fiber per cc for most industrial or construction work sites would be difficult at this period of time" (Tr. 215). Additional doubt was voiced by the chairman of the Shipyard Employment Standards Advisory Committee, "* * * an action level, that is 0.05 fibers per cc, is not appropriate or reasonable due to inconsistencies and non-reproducibility with the sampling and analytical methodology" and noted concern that shipyard environments were especially likely to have high levels of background dust which could overload sampling devices, making determinations at that level more difficult (Tr. 345). Other commenters supported the proposed deletion of an action level (Ex. 7-2, 7-39, 7-99,7-104, 7-120, 7-146).

Asbestos

In 1992 OSHA amended the definition of "asbestos" from the 1986 standards. The non-asbestiform varieties of the minerals actinolite, tremolite and anthophyllite are no longer included in the definition of asbestos. In 1986 OSHA determined that although tremolite, actinolite and anthophyllite exist in different forms, all forms of these minerals would continue to be regulated. Following promulgation of the rule, several parties requested an administrative stay of the standard claiming that OSHA improperly included non-asbestiform minerals. A temporary stay insofar as the standards apply to the non-asbestos forms of tremolite, actinolite and anthophyllite was granted and the Agency initiated rulemaking, proposing to remove these forms from the scope of the asbestos standards. Following a public comment period and public hearing, OSHA issued its final decision to delete non-asbestiform tremolite, anthophyllite and actinolite from the scope of the asbestos standards (57 FR 24310, June 8, 1992). The Agency, in evaluating the record, found that "evidence is lacking to conclude that non-asbestiform tremolite, anthophyllite and actinolite present the same type or magnitude of health effect as asbestos," and that the failure to regulate them as asbestos does not present a significant risk to employees.

Classification of Asbestos Work (Classes I-IV)

In the Construction and Shipyard Employment Standards, OSHA is adding definitions for four classes of activities which trigger different provisions in the standard. Those activities presenting the greatest risk are designated Class I work, with decreasing risk potential attaching to each successive class. The Construction and Shipyard Employment Standards regulate Class I, II and III work; all three standards regulate Class IV work.

"Class I" work is defined as activities involving the removal of thermal system insulation and sprayed-on or troweled-on or otherwise applied surfacing ACM (asbestos-containing material) and PACM (presumed asbestos-containing material); "Class II asbestos work" is defined as removal of ACM or PACM which is not TSI or surfacing ACM or PACM; "Class III asbestos work" is defined as repair and maintenance operations which are likely to disturb ACM, or PACM; Class IV operations are custodial and housekeeping operations where minimal contact with ACM and/or PACM may occur.

Class I asbestos work involves removal of surfacing materials sprayed or troweled or otherwise applied to surfaces, and removal of thermal system insulation. Surfacing materials include, for example, decorative plaster on ceilings or acoustical ACM on decking or fireproofing on structural members. Thermal system insulation includes, for example, ACM applied to pipes, boilers, tanks and ducts. Based on the record, OSHA has determined that the prevalence of these materials and their likelihood of significant fiber release when disturbed, requires rigorous control methods which OSHA has set out in the standards.

Class II asbestos work involves removal of any other asbestos-

containing material -- which is not TSI or surfacing ACM. Examples of Class II work are removal of floor or ceiling tiles, siding, roofing, transite panels. EPA refers to these materials as "miscellaneous ACM" in the "Green Book." (Ex. 1-183) Work practices and other control measures to be employed in removing these materials are discussed later in this preamble under the methods of compliance section.

Class III asbestos work are defined as repair and maintenance activities involving intentional disturbance of ACM/PACM. Class III is limited to incidental cutting away of small amounts (less than a single standard waste bag) of ACM/PACM, for example, to access an electrical box for repair.

The first three classes of asbestos work are intended to cover the kinds of asbestos work which under the 1986 construction standard were designated "asbestos removal, demolition, and renovation operations," including "small-scale, short-duration operations, such as pipe repair, valve replacement, installing electrical conduits, installing or removing drywall, roofing, and other general building maintenance or renovation."

The classes are exclusive. For example, the stripping of 50 linear feet of thermal system insulation, which has not been positively identified as non-asbestos containing material is Class I, for it is the removal of PACM. Repair of a valve covered by ACM is Class III, since "removal" is not taking place. Removal of roofing material containing ACM is Class II, since roofing material is not high-risk ACM. OSHA believes dividing activities by "Classes" will be clearer than the prior system in the 1986 standard which prescribed different precautions for "small scale, short duration work," which it then defined by example. As noted in several places in this document this was confusing to employers, to the Court and to OSHA itself. A more extensive discussion of the "Class" system of designating work with asbestos-containing materials is contained in the discussion on "Methods of Compliance" provisions later in this preamble.

Class IV work is defined as maintenance and custodial activities during which employees contact ACM and PACM and activities to clean up waste and debris containing ACM and PACM. This includes dusting surfaces, vacuuming carpets, mopping floors, cleaning up ACM or PACM materials from thermal system insulation or surfacing ACM/PACM. Workers may contact ACM or PACM when performing a wide variety of routine jobs that result in incidental disturbance, such as changing a battery in a smoke detector attached to a ceiling containing ACM or PACM, polishing floors containing asbestos, and changing a light bulb in a fixture attached to an asbestos containing ceiling.

For custodial work, the Class IV characterization applies to situations where there is an indication that surfaces are contaminated with ACM or PACM. One indication would be identification of the ACM or PACM sources of the debris or dust; such as visibly damaged, or degraded, ACM or PACM in the vicinity. Visibly damaged, degraded, or friable ACM or PACM are indications that surface dust could contain asbestos, and Class IV protection applies. OSHA requires in (g)(9) that such dust or debris be assumed to be ACM or PACM. Another indication could be an analytical test to determine whether the surface dust itself contains asbestos. Since dust of carpets may not be visible, visible dust on other surfaces along with the presence of ACM/PACM nearby would indicate that cleaning the carpet is Class IV work.

The general industry standard also includes requirements for maintenance and custodial operations which mirror Class IV requirements in the construction standard. These would apply to activities which are not traditionally viewed as construction activities, and which, as contended by certain participants in this proceeding, may not be covered by the Construction Safety Act (40 U.S.C. 333). As further discussed in the preamble discussion relating to paragraph (a), Scope and Application, examples of these activities are clean-up in areas where asbestos-containing dust or debris is present and removing light fixtures located near "high risk" surfacing material.

Some Class IV work was covered by the earlier standards, yet the coverage was incomplete. The general industry standard regulated housekeeping activities, and housekeeping activities were also included in the construction standard to be covered if they were part of a construction job. Precautionary maintenance guidelines to avoid disturbing ACM were addressed in Appendix G of the construction standard. OSHA believes that the switch from the regulated "housekeeping" activities to the Class IV definition is clearer and reduces loopholes. The custodial activities covered in either event can clearly create asbestos dust and expose custodial employees to that dust. Data in the record show that custodial activities can produce not insignificant asbestos exposure levels. Therefore, the work practices required to reduce that dust are clearly necessary to reduce significant risk to custodial workers.

By establishing a Class IV, OSHA is rejecting various recommendations that some activities, potentially involving asbestos disturbance, would result in de minimis risk, and as such should not be regulated (See further discussion concerning Methods of Compliance). The new definition of Class IV work, the removal of the non-mandatory appendix, and coverage of these activities both under general industry standard and the construction standard and shipyard employment standards clarify the standards' application to such work.

OSHA requested comments on setting a cut-off for asbestos-containing material with minimal asbestos content. There was overwhelming support for a 1% cutoff for ACM which would be consistent with EPA rules. The Hazard Communication Standard labeling and training provisions require labeling of materials which contain more than 0.1% asbestos. EPA defines asbestos containing material as: "Any material containing more than one percent asbestos." (NESHAP and Green Book p. 30). OSHA has no information to indicate what proportion of building materials fall into the category of containing more than 0.1% and less than 1.0% asbestos. EPA has listed building materials by their asbestos content and among those included on the list, only surfacing ACM ranged down to 1% (and up to 95%) (EPA "Purple Book," Ex. 1-282). Some participants, including NIOSH have expressed concern that even 1% may be below the accuracy level for optical microscopic methods. (Ex. 7-145, 162-39). Among those who dealt with the issue, most supported the 1.0% cutoff, most citing its consistency with EPA (Ex. 7-5, 7-6, 7-21, 7-43, 7-51, 7-74, 7-76, 7-99, 7-106, 7-111, 7-120, 7-137, 151, 162-59, 162-29). OSHA agrees that a cutoff of 1.0% asbestos is appropriate for asbestos containing building materials and has included this value in its definitions of ACM.

Closely Resemble

Included in the construction and shipyard employment standards is a definition for the term "closely resemble," which is the term used in the regulatory text to limit the use of historic exposure data to predict exposures. It is defined as circumstances where "the major workplace conditions which have contributed to the levels of historic asbestos exposure are no more protective than in the current workplace." OSHA's intent is to allow data reflecting past exposures to be used to predict current exposures only when the conditions of the earlier job were not more protective, i.e., employees were not better trained, work practices were not used more consistently, and no more supervision was present.

Competent Person

OSHA has amended the definition of "competent person" in the construction standard and included it in the Shipyard Employment Standard as a "qualified person." The definition is based on the definition of "competent person" in the general construction standard, 29 CFR 1926.32(f), i.e. "one who is capable of identifying existing asbestos hazards in the workplace and who has the authority to take prompt corrective measures to eliminate them," but adds a specific training qualification. The training provisions require a competent person take a course which meets the requirements of EPA's Model Accreditation Plan (40 CFR 763, Subpart E). OSHA believes that specific training is needed so a "competent person" will have adequate knowledge to perform the competent person's responsibilities for Class I and II work. A Class II and Class IV "competent person" must undergo "Operations and Maintenance" (O&M) training as developed by EPA. Further discussion of these issues is found later in this document.

The revised definition deletes from the definition a list of duties to be performed by the competent person. Duties are more appropriately set out in other regulatory paragraphs which are prescriptive, rather than in the "definition" section. In response to the court's remand, OSHA has also expanded the scope of the competent persons's duties so that a competent person must supervise all asbestos activities under the construction standard. As noted, these requirements are set forth in other regulatory paragraphs which govern conditions of work in covered activities.

The shipyard employment standard does not use the term "competent person," because that term has a unique definition under Part 1915. OSHA has accepted SECSAC's recommendation that the term "qualified person" should be used to designate a person with the same duties under the shipyard employment standard.

Critical Barriers

OSHA is adding a definition for the term "critical barriers" whose use is required in certain asbestos operations. These are defined as plastic sheeting or equivalent material placed over openings to the work area. These barriers are effective when they seal all openings into a work area. Critical barriers can be other physical barriers sufficient to prevent airborne asbestos in a work area from migrating to an adjacent area.

Disturbance

OSHA has added a definition for "disturbance" to all three standards to distinguish it from removal. In this definition disturbance means any contact with ACM/PACM which releases fibers or which alters its position or arrangement. It also includes operations which disrupt the matrix or render it friable or which generate visible debris from it. A quantitative cutoff of disturbance is given -- the amount of ACM/PACM so disturbed may not exceed the amount that can be contained within one standard sized glove bag or waste bag. OSHA believes that certain jobs, e.g., repairing leaking valves, often require asbestos to be cut away to gain access to a component. If the amount of asbestos so "disturbed" is contained in one bag, Class I precautions are not necessary.

Glove Bag

The term "glove bag" is also defined in the standards as a plastic bag-like enclosure affixed around ACM with glove-like appendages through which material and tools may be handled.

Homogeneous Area

The presumption that a material contains asbestos may be rebutted by sampling a "homogeneous" area of the presumed ACM to determine its asbestos content. OSHA has defined "homogeneous area" in much the same way it is defined by EPA as an area of surfacing material or thermal system insulation that is uniform in color and texture.

Industrial Hygienist

A definition for "Industrial Hygienist" is included in the standards as a professional person qualified by education, training, and experience to anticipate, recognize, evaluate and develop controls for occupational health hazards.

Initial Exposure Assessment

"Initial Exposure Assessment," including "Negative Initial Exposure Assessment" are terms used in the construction and in the shipyard standards. It means a required assessment by a "competent person" concerning the exposure potential of a specific asbestos job, or series of similar asbestos jobs. A "Negative Initial Exposure Assessment" is such an assessment in which it is concluded that employee exposures during the job are likely to be consistently below the PELs. Assessments must be based on information and data which are allowed pursuant to criteria in paragraph (f). The results of "Initial monitoring," no longer required for each job, should be considered, but do not necessarily constitute an adequate "assessment" if they would not represent all worst-case employee exposures during the entire job.

Modification

Alternatives or modifications to listed control methods are allowed when the employer demonstrates that such a "modification" still provides equivalent worker protection. OSHA does not intend that changes in a control method which decrease the safety margin of a material or omitting a procedure be permitted by calling it a "modification." A "modification" means a changed or altered procedure, material which replaces a procedure, material or component of a required system. For example, a new test proven successful in detecting leaks might be substituted for required "smoke tests." Omission of a procedure or component, or a reduction in the stringency or strength of a material or component is not considered a "modification" under this section.

Presumed Asbestos-Containing Material (PACM)

In all three standards, "presumed asbestos containing material," "PACM"

means thermal system insulation and sprayed on and/or troweled or otherwise applied surfacing material in buildings constructed no later than 1980. OSHA has found that these materials are "high risk" if asbestos-containing. OSHA bases this on the record, including the HEI Report which states that "thermal system insulation and surface treatments (fireproofing, acoustical and decorative finishes) stand out in importance for their potential for fiber release and subsequent exposure to [building] occupants" (Ex. 1-344, p. 4-5). Although these materials may have been installed in small quantities after 1980, OSHA finds that their installation is unlikely after that date.

Project Designer

OSHA has adopted a definition like that of EPA for a "Project Designer"

-- a person who has successfully completed the training requirements for an abatement project designer established by 40 USC 763.90(g).

Removal

"Removal" means all operations where ACM and/or PACM is removed from a building component, regardless of the reason for the removal. It includes those maintenance, repair, renovation and demolition activities where ACM and/or PACM removal is incidental to the primary reason for the project, as well as where removal of ACM and/or PACM is the primary reason for the project. Removal should be distinguished from "disturbance" which includes "cutting away" a small amount of ACM or PACM.

Regulated Area

"Regulated area" is included in all three standards. All three, like the 1986 standards, require the establishment of such an area where the employer believes that the PEL will be exceeded. Now, the construction and shipyard employment standards add that such area must be established also where Class I, II and III activities will take place, regardless of exposure levels. Also, the specific actions required of the employer to demarcate a regulated area are deleted from the definition, and are placed in the appropriate prescriptive paragraph, in this case paragraph (e)(6).

(3) Permissible Exposure Limits

Paragraph (c) General Industry, Construction and Shipyard Standards. In all three standards, the eight hour time-weighted average permissible exposure limit is changed from an eight hour time weighted average (TWA) of 0.2 f/cc to a TWA of 0.1 f/cc in the revised final rules. As noted in the 1990 proposal and in the preamble discussion above, OSHA's decision to reduce the PEL across the board responds to the Court's directive to consider whether to establish operation-specific exposure limits, since the Court noted that on the record of the 1986 standards, it appeared feasible to reduce the PEL to 0.1 f/cc limit in many industry sectors. OSHA has rejected "operation-specific" PELs for the wide variety of operations that expose employees to asbestos. OSHA proposed and these final standards adopt required operation-specific work practices, in addition to an across-the-board PEL reduction to 0.1 f/cc. OSHA expects that the risk reduction accomplished by this two-pronged approach will be at least as great as would operation-specific PELs. First, the required controls are found to be capable of achieving maximum exposure reduction on an operation-by-operation basis. Second, since OSHA has found that specific work practices are feasible, the Agency expects a higher compliance rate and thus, greater risk reduction than if practices were not specified. Third, in operations where particular controls are specified, the PEL is a backstop; alerting employers where additional controls are needed or closer surveillance is required; in all operations the PEL is a measurable and comparable value, which cannot be exceeded without further action by the employer to reduce exposures.

At the time of the proposal in 1990, the question of whether the proposed PEL reduction would reduce a still significant risk had already been given a tentative answer by the Court. The D.C. Circuit Court of Appeals, in remanding the issue of lowering the PEL to the Agency, noted that based on the 1984 risk assessment, the excess risk stemming from average exposures of 0.1 f/cc "could well be found significant." BCTD v. Brock, 838 F.2nd at 1266." (55 FR at 29714).

In the proposal, OSHA stated that it believes "that compliance with proposed amendments to reduce the PEL to 0.1 f/cc as a time-weighted average measured over 8 hours would further reduce a significant health risk which exists after imposing a 0.2 f/cc PEL" (55 FR 29714, July 20, 1990). OSHA's 1984 risk assessment showed that lowering the TWA PEL from 2 f/cc to 0.2 f/cc reduced the asbestos cancer mortality risk from lifetime exposure from 64 to 6.7 deaths per 1,000 workers. OSHA estimated that the incidence of asbestosis would be 5 cases per 1,000 workers exposed for a working lifetime under the TWA PEL of 0.2 f/cc. Counterpart risk figures for 20 years of exposure are excess cancer risks of 4.5 per 1,000 workers and an estimated asbestosis incidence of 2 cases per 1,000 workers.

OSHA's risk assessment also showed that reducing exposure to 0.1 f/ cc would further reduce, but not eliminate, significant risk. The excess cancer risk at that level would be reduced to a lifetime risk of 3.4 per 1,000 workers and a 20 year exposure risk of 2.3 per 1,000 workers. Consequently significant risk would be reduced substantially. However, OSHA concluded therefore that continued exposure to asbestos at the TWA permitted level and action level would still present residual risks to employees which are significant.

The Court did not ask and OSHA did not undertake to review its earlier risk assessment in the proposal. At the hearing in January, 1991, Mr. Martonik, spokesperson for OSHA was asked by Mr. Hardy, representing the Safe Building Alliance (SBA), if OSHA was planning to update the earlier risk assessment as part of this proceeding. Mr. Hardy stated that "a number of parties have suggested to OSHA that its risk assessment from 1984, as relied on in the 1986 final rule, is outdated" (Tr. 30). Mr. Martonik responded that "we will have to consider all information we receive and determine relevance in this rulemaking after the record is closed. (Ibid).

Other parties questioned OSHA's continuing reliance on the 1984 risk assessment. The Asbestos Information Association (AIANA) testified that "OSHA's 1984 risk assessment fails to take into account the scientific community's consensus that chrysotile exposures hold lower risk than the Agency estimates * * * we do not believe that the risk assessment that is six years old relies on the best available evidence." AIANA requested OSHA to convene experts, as part of this hearing process "to revise its asbestos risk assessment." (Tr. 530), this was the major objection to OSHA's earlier risk assessment. Some participants voiced similar objections. (Ex. 7-88, 7-110, 7-104, 7-120, Ex. 145, 151), while others were of the opinion that chrysotile had the same potency as other forms of asbestos (see Ex. 119 C, 1-136, 125, Att. 6, 143 Att C, 143 Att. D.).

Although as noted above, the issue of the continuing validity of OSHA's earlier risk assessment was not remanded to the Agency for reconsideration, implicit in OSHA's proposal to lower the PEL to 0.1 f/ cc is OSHA's determination based on the 1984 risk assessment, that the lower exposure limit is necessary to reduce a still significant occupational risk.

After a comprehensive review of the evidence submitted concerning the validity of the 1984 risk assessment, OSHA has determined that it will continue to rely on the earlier analysis. The Agency believes that the studies used to derive risk estimates remain valid and reliable, and that OSHA's decision to not separate fiber types for purposes of risk analysis is neither scientifically nor regulatorily incorrect.

There are at least three reasons for OSHA's decision not to separate fiber types. First, OSHA believes that the evidence in the record supports similar potency for chrysotile and amphiboles with regard to lung cancer and asbestosis. The evidence submitted in support of the claim that chrysotile asbestos is less toxic than other asbestos fiber types is related primarily to mesothelioma. This evidence is unpersuasive, and it provides an insufficient basis upon which to regulate that fiber type less stringently.

As OSHA explained in the preamble to the 1986 standards,

* * * to summarize the data on risk differential by asbestos fiber type, human epidemiological studies have suggested that occupational exposure to amphiboles is associated with a greater risk of mesothelioma than is exposure to chrysotile * * * No clear risk differential for lung cancer or other asbestos-related disease has been demonstrated by epidemiological studies. Animal experiments, however, have indicated that chrysotile is a more potent carcinogen than amphiboles when administered by inhalation or intrapleural injection * * * (51 FR at 22628).

OSHA agreed with the testimony of Dr. Davis, who stated that "the evidence cannot answer * * * with certainty * * * if "one fiber * * * of amphibole (is) more dangerous than one fiber * * * of chrysotile." (Ibid).

Second, as stated in the 1986 asbestos standard, even if OSHA were to accept the premise (which it does not), that chrysotile may present a lower cancer risk than other asbestos fiber types, occupational exposure to chrysotile asbestos still presents a significant risk of disease at the revised PEL (See 51 FR 22649, 22652). In particular, asbestosis, the disabling and often fatal fibrosis of the deep portions of the lung, is caused by exposure to all types of asbestos. The evidence on this is strong and no new information has been presented to contradict this. As stated above, OSHA estimated asbestosis risks at 0.2 f/cc exposures as an unacceptably high 5 cases per 1000 workers. Thus, asbestosis risks alone justify the regulation for chrysotile.

Lung cancer risks associated with chrysotile exposures are also high -- 6.7 lung cancer deaths per 1000 workers exposed to 0.2 f/cc for a full working lifetime. OSHA notes that SBA's witness, Dr. K. Crump acknowledged that "(t)here's not a clear difference, * * * even in humans, for lung cancer * * * in terms of distinguishing the potency of amphiboles vs. chrysotile." (Tr. 4220).

Third, the record shows that employees are likely to be exposed to mixed fiber types at most construction and shipyard industry worksites most of the time. Assigning a higher PEL to chrysotile would present the Agency and employers with analytical difficulties in separately monitoring exposures to different fiber types. Thus, regulating different fiber types at differing levels, would require more monitoring all the time and would produce limited benefits (51 FR 22682).

Consequently, OSHA believes that its conclusion to treat all asbestos fibers as having a similar potency in the occupational setting remains valid. Most of the evidence submitted to the remand rulemaking duplicated evidence submitted to the 1986 standards' record, or was cumulative to the earlier body of evidence. For example AIANA appended its 1988 submission to the EPA, consisting of numerous studies and reports. Some of these documents were considered by OSHA in the prior rulemaking. There, OSHA had stated that the 1983 Berry and Newhouse study of friction materials manufacturing workers which found nonsignificant increases in lung cancer mortality, was inconsistent with other studies showing that low level asbestos exposure resulted in excess lung cancer mortality, because of the relatively short follow up period used (51 FR 22618).

Other studies involved lung burden analyses of mesothelioma victims, apparently showing that the pulmonary content of chrysotile was within the range of the general population, whereas amphibole content was significantly elevated compared to the general population (see e.g. Churg, Malignant Mesothelioma in British Columbia in 1982, Cancer, 2/85, 672). OSHA noted in the preamble to the 1986 rule, that there is a difference in tissue retention which would account for the autopsy results and cited a study by Glyseth et al. (Doc. 33-C, Ex. 312) which supported that explanation. OSHA also noted that "the differential lung retention of various fiber types has been demonstrated in animals," citing a study by Wagner which found that animals exposed to chrysotile fibers developed lung cancer even though a smaller amount of chrysotile was retained in the lung compared to similar tests with amphiboles.

Dr. Weill believed that "these differences in tissue persistence may wholly or partially explain the observations [that exposure to amphiboles are associated with a higher prevalence of mesothelioma] in human * * * population * * *. Non-confirmation of fiber type differences in animal experiments may be related to the much shorter life span * * * [of experimental animals, which would not allow] the effects of varying tissue-persistence to be expressed" (Doc. 33-C, Ex. 99, p.18; 51 FR 22628). Therefore OSHA had reviewed and evaluated in the earlier rulemaking a portion of the evidence submitted by proponents of differential regulation of fiber types, and had rejected the claim that chrysotile should be regulated less stringently.

Some new evidence on the issue of differential risks of asbestos fiber types was submitted by both supporters and detractors of that theory.

In support of the position that chrysotile asbestos exposure is equivalent in risk to amphibole asbestos exposure, BCTD submitted studies which indicated excess mesothelioma cases in workers exposed solely to chrysotile asbestos (see Ex. 119 C, 1-136, 125, Att.6, 143 Att C, 143 Att. D). In support of the opposing claim that chrysotile has reduced carcinogenic potential, AIANA and SBA submitted additional evidence. For example, AIANA submitted the World Health Organization's 1989 working report which recommended that the exposure limit for chrysotile should be reduced to 1 f/cc or below (8 hour TWA), where it was recommended that exposure to crocidolite and amosite asbestos be prohibited (Ex. 21 A, p. 9). In particular, two papers by Mossman, et. al, are cited as the basis for the claim that a scientific "consensus" believes that chrysotile carries a reduced carcinogenic risk (Ex. 1-153, 151). Thus AIANA states that "since OSHA issued its 1984 asbestos risk assessment, the scientific consensus that chrysotile asbestos poses lesser risks has solidified" (Ex. 142 at 3).

However, OSHA notes that various participants in this rulemaking, including NIOSH and Dr. Nicholson, disputed the existence of such a consensus. Dr. Nicholson and others including Dr. Landrigan, in a letter to Science, (Ex. 1-155), dispute various interpretations of data in Mossman et al.'s paper, and challenge the conclusion that chrysotile asbestos carries little cancer risk. Nicholson et al, point out that human studies show excess lung cancer risk that is proportionate to exposure across all fiber types, and that animal tests confirm these relationships. OSHA believes that the scientific community has not achieved "consensus" on these issues.

Among the studies submitted in support of the lowered risk of chrysotile asbestos, are those of Churg, and others showing that the lung burden of mesothelioma victims is predominantly amphibole, even though high chrysotile exposure levels were reported. As noted above, this line of argument was presented in the earlier asbestos rulemaking, and OSHA had concluded that lung burden studies are inconclusive. Additional response to this argument is provided by Dement who notes that "(t)he biological significance of post-mortem lung fiber burden data has yet to be established. These data are not useful as a predictor of disease for several reasons. Chrysotile is known to split longitudinally and partially dissolve in the lung whereas amphiboles remain in the lungs for years without significant dissolution * * *. Measurements of tissue fiber burdens many years after first exposure may bear no relationship to the carcinogenic events which likely have taken place many years before clinical manifestation of cancer." (Ex. 1-273) BCTD pointed out in its post-hearing brief, that "Dr. Landrigan testified, while the observation that chrysotile does not last as long in the lungs as other forms of asbestos is not new knowledge (Tr. 1074), there is recent evidence that chrysotile is "the most effective of the three major fiber types at migrating to the pleura, that it is present in substantial amounts in pleural plaques and mesotheliomas, even in circumstances where it is not present or minimally present in the lungs themselves" (Tr. 1074).

The Agency also notes that the HEI report, in summing up its discussion of its literature search of studies examining the issue of the relative potency of chrysotile in inducing mesothelioma, stated: "(t)he evidence that chrysotile rarely causes pleural mesothelioma is not conclusive "* * * and concluded that the absence of mesothelioma in one of the "two cohorts of heavily exposed asbestos workers who worked only with chrysotile * * * seems likely to be due at least in part to chance" (Ex. 1-344 p. 6-23).

HEI concluded that "the mesothelioma risk for chrysotile was an issue of disagreement; some members of the Literature Review Panel held the view that a lower estimate should be recommended, as it would be more consistent with available data. The crucial issues, neither of which can be resolved unequivocally, are (1) what proportion of the mesotheliomas observed in groups such as the U.K. textile workers and the U.S. insulation workers were caused by their exposure to crocidolite or amosite; and (2) whether the best general estimate of the ratio of mesothelioma to excess lung cancer caused by chrysotile is provided by the Quebec miners and millers (about 1:4 or 1:5), or by the South Carolina textile workers handling Quebec fiber (zero)" (Ex. 1-344 p. 6-32).

Thus, although there is some evidence linking chrysotile to a lower mesothelioma rate than some amphibole fiber types, OSHA believes that there is insufficient evidence to show that chrysotile does not present a significant mesothelioma risk to exposed employees. Furthermore, the major disease linked to asbestos exposure, lung cancer, occurs at the same frequency among employees exposed to equivalent doses of chrysotile or to amphibole asbestos fiber types. Indeed, evaluation of all of the evidence indicates that chrysotile asbestos presents a similar significant risk of lung cancer and asbestosis as other forms of asbestos. Since these adverse health effects constitute the majority of diseases related to asbestos exposure, OSHA is still of the opinion that chrysotile exposure should be treated the same as other forms of asbestos.

In addition to contentions that OSHA's risk assessment had overstated asbestos risks because it treated the risks from all asbestos fiber types equally, other contentions were made that the earlier risk assessment may have understated the risks from asbestos, because it ignored evidence of the incidence of pleural plaques, and other asbestos disease which occurred in workers exposed at low levels, primarily as building custodians. The earlier risk assessment in 1984 focused on whether there was a significant risk of cancer and asbestosis at various levels of cumulative exposure. During this hearing, various labor groups stated their position that the presence of pleural plaques in asbestos exposed employees is not only a marker of asbestos exposure, but also an independent "material impairment" because they are associated with a greater risk of lung function impairment and pleuritic pain. Pleural plaques are focal areas of fibrous thickening of the pleura, the membrane lining the lung. Further, suggestions were made that OSHA should reduce its PELS to correspond to these increased risks of "material impairment" which occurred at lower exposure levels (see e.g., Ex. 143 at 35-37).

Evidence submitted during the rulemaking consisted of testimony and studies which in the view of some participants showed lung function decrement and resulting excess disease among workers exposed at low levels. For example BCTD witness Dr. Christine Oliver described various studies and concluded:

Pleural plaques * * * were a predictor for increased mortality from lung cancer and malignant mesothelioma in subsequent years * * * pleural plaques have also been shown to be associated with decrement in lung function * * * At the very least, pleural plaques are a marker for exposure, sufficient to increase risk for lung cancer and for malignant mesothelioma, and they have also been associated with loss of lung function (Tr. 1035-6).

Dr. Oliver recommended medical surveillance of those exposed to asbestos in their capacity as custodians in buildings.

The studies considered by Dr. Oliver consisted of one involving 120 Boston public school custodians (Tr. 1026) which she conducted and found pleural plaques in 33% (N = 40) of the group. Further she noted that in 21% (of the 40, or 12 individuals) there was no known exposure to asbestos outside work as school custodian. In 18% of the group and 17 % of those with no outside exposure to asbestos, she observed a restrictive pulmonary defect, significantly associated with duration of employment as school custodian. Other studies described by Dr. Oliver, in the docket include: a study of 666 New York school custodians, reporting only x-ray data (Ex. 47). For all groups of workers, the lung abnormality seen on x-ray was associated with duration of work as custodian: a study of 1,117 insulation workers (likely to have had extensive asbestos exposure) by Dr. Irving Selikoff, in which workers were followed for up to 27 years prospectively, in which pleural plaques were found and which were concluded to be predictive of lung cancer mortality (Tr. 1036 and Ex. 124A): a study, by Balmes (Ex. 124 DD, Tr. 1036, Ex. 1-374) of approximately 900 school district employees in California were determined as likely to have been exposed to asbestos. The authors concluded, "More than 11 percent of workers known to have sustained exposure to ACM in school building, without history of exposure to asbestos prior to school district employment, and with at least 10 years of employment with the district had radiographic evidence of parenchymal asbestosis and/or asbestos-related pleural thickening" (Ex. 1-374, p. 547). After adjusting for smoking and age, the relative risk was 1.3 times greater for those with 10 years or more employment compared with those who had just begun working for the school district.

In addition to the occurrence of pleural plaques which are viewed as presenting an independent material impairment of health due to low level asbestos exposures, Dr. Oliver cited other studies which correlated low level asbestos exposure with mesothelioma. Thus, a study by Dr. H. Anderson (Tr. 1032 and Ex. 124 EE, Ex. 1-374 using information on mesothelioma cases from a Wisconsin Cancer Registry, analyzed 359 deaths from 1959 to 1989. Using death certificate occupational information, the researchers hypothesized 41 as likely to have been exposed to asbestos in buildings. For 10 (34%), no other likely source of asbestos exposure was identified. The paper concluded that "individuals occupationally exposed to in-place ACBM are at risk for the subsequent development of mesothelioma" (Ex. 1-374, p. 570).

SBA submitted a critique of these studies which they commissioned by Drs. H. Weill and J. Hughes (Ex. 122). They suggested potential biases in these studies, that Dr. Oliver's study subjects were volunteers, the study had a low participation rate, they had used a non-standard classification system, and did not adequately account for age in relating restriction to lung function. These reviewers concluded that spirometric functional measurements were not related to the presence of plaques and that reduced lung volume could result from other factors. Drs. Weill and Hughes also examined the other studies, and argued that Dr. Selikoff's were "fatally flawed" due to the potential for development of unmeasured changes during the 27 year period of follow-up, and that both the Anderson and Balmes studies failed to adequately adjust for age, smoking and other direct asbestos exposures. Other reports cited by BCTD were dismissed because of potential sources of bias.

Dr. Oliver rebutted these arguments (Ex 143, Attachment F). She argued that she had adequate controls, adequately accounted for age and demonstrated that pleural plaques were significantly associated with both latency and duration of work as custodian in the total group and in the group with no known other exposure, that lung restriction was significantly associated with duration of work as a custodian, and that pleural plaques mark increased risk for lung cancer mortality.

Dr. Levin also responded to the reviewer's criticism of his studies with Dr. Selikoff (Ex. 143, Attachment G). He pointed out that all x-rays had been read by a single reader, Dr. Selikoff, and that there is no evidence that smoking without asbestos exposure increases appearance of the small irregular opacities in the lung seen on the x-rays in their study. He further noted that in his study only actively working custodians were included and were therefore a "survivor" group and would therefore not be expected to report pulmonary dysfunction frequently. He claimed that relatively unexposed subject groups would not be expected to have more than an upper limit of 3% pleural plaques.

Dr. Anderson also responded to the Weill/Hughes comments (Ex. 143, Attachment H). He asserted that the review fails to explain how biases would significantly increase odds ratios in the study, that misclassification often is random and biases toward not detecting a difference between the study and control groups. He also questioned existence of evidence that smoking without asbestos exposure causes pleural thickening or irregular opacities.

The review of available literature, including the studies mentioned above by the Health Effects Institute, resulted in its the estimation that the prevalence of pleural plaques in the general population to be about 5% (Ex. 1-344, p. A2-9). Although HEI advised caution in interpreting the existing studies due to lack of specificity and sensitivity of methods used and couched its conclusions in cautious terms, they concluded: "* * * there is now persuasive evidence implicating asbestos-related pleural disease as an independent cause or indicator of functional impairment and possibly even disability * * * On the individual level, pleural disease may be the only indication of asbestos exposure, may explain symptoms and function impairment, and may predict future deterioration in lung function" (Ex. 1-344 p. A2-12).

OSHA agrees that health effects such as lung function impairment and pleuritic pain would be considered "material impairment," if substantial evidence supports the link to pleural plaques. OSHA concludes that the scientific data indicate that pleural plaques are primarily associated with asbestos exposure, and that they have occurred and still may at relatively low exposure levels.

However, OSHA does not believe that the data are available to permit OSHA to do a separate risk assessment for these effects which would in a major way add to the present assessment. The risk assessment on which OSHA has based its significant risk determinations for the 1986 and newly revised standards, calculated the incidence of mesothelioma, lung and other cancers and asbestosis, diseases based on a substantial amount of both mortality and exposure data. The data concerning lung function decrement and pleural plaques lack exposure information and would make quantitative risk estimates for these health effects less precise than the data for other forms of asbestos-related disease upon which OSHA is relying.

A separate risk assessment is also unnecessary. OSHA believes that the revised regulations are already regulating at the margin of what is feasible, in terms of levels to be achieved, and controls which are required. OSHA has imposed necessary, feasible and well supported work practices for custodial work, which should reduce custodial exposures well below the historic levels (indeterminate) which may have been experienced by the workers studied in the above reports.

More generally, there would be remaining significant risk at this new 0.1 f/cc exposure limit if there were not other provisions to these standards. However, the exposure limit is accompanied by mandated work practice controls and requirements for hazard communication, training and other provisions. Together these will very substantially reduce that remaining significant risk, although the exact amount of that reduction cannot be quantified. In addition, it would be difficult to measure accurately in the industrial setting levels lower than those in these standards. OSHA believes its approach of setting a PEL which is reliably measurable, yet, imposing work practices and ancillary provisions for operations regardless of measured fiber levels will result in risk reduction well below that expected from just enforcing the 0.1 f/cc PEL. Thus, a lower PEL would not produce significant worker benefit.

(4) Multi-Employer Worksites

Paragraph (d) Construction and Shipyard Employment Standards. OSHA is retitling paragraph (d) "multi-employer worksites." The first provision, the same regulatory text as in the 1986 construction standard, requires that an employer whose work requires the establishment of a regulated area must inform other on-site employers of the asbestos work, and how other employees will be protected from hazards stemming from that work. In addition, new provisions follow which set out the compliance responsibilities of employers on multi-employer worksites.

In 1990, OSHA had proposed more comprehensive provisions governing communication of asbestos hazards among all employers, building and facility owners and employees, in a revised paragraph (d). These final standards expand communication provisions but repositions them in paragraph (k), "communication of hazards." A discussion of those provisions is found below in this preamble under that heading.

Paragraphs (d)(2) and (3) set out the compliance responsibilities of employers on multi-employer worksites. They acknowledge that on asbestos work sites, like other construction sites, employees exposed to a hazard are not always the employees of the employer who created the hazard.

Paragraph (d)(2) incorporates the rules now applied in enforcement actions governing multi-employer construction sites generally, to assure that all employees on such a site receive the protection intended by the standards.(See Gelco Builders, Inc. 6 BNA 1104). The standard explicitly requires asbestos hazards to be abated "by the contractor who created or controls the source of asbestos contamination."

In addition, paragraph (d)(3) sets forth the duties of the employer of employees who are exposed to asbestos hazards, but who did not create the source of contamination. One, such employer may request the contractor with control of the hazard to take corrective action. For example, if there is a breach of an enclosure within which asbestos work is being performed, the employer of employees working outside that enclosure should request the asbestos contractor who erected the enclosure to repair the breach immediately, as required by paragraph (d)(2). If the repair is not made, and if employees working outside the enclosure are exposed to asbestos in more than de minimis amounts, the employer of those employees should either remove them from the worksite pending repairs, or consider his employees to be working within a regulated area and comply with the provisions of paragraph (e) governing exposure assessments and monitoring of employees who work within such areas. If the employer of employees exposed to asbestos because of the failure of controls installed by another contractor, is the general contractor of the construction project, as such he has supervisory control over the entire worksite including the regulated area, and is responsible for violations which could be abated or prevented by the exercise of such supervisory capacity.

Paragraph (d)(3) of the construction standard states the enforcement rule that regardless of who created a hazard, the employer of exposed employees is required to comply with applicable protective provisions to protect his employees. An example recited in the regulatory text presents the situation of employees working immediately adjacent to a Class I regulated area. If there is a breach of the enclosure or the critical barriers surrounding the asbestos work, employees working immediately adjacent to the work may be exposed to asbestos. The employer responsible for erecting the enclosure is required to insure its integrity. However, in the event that such repair is delayed or not made, the employer of the exposed "bystander employees" must designate a "competent person" to evaluate the exposure potential, conduct initial monitoring or an "exposure assessment," and supervise other required protective actions. The evaluation may include the amount of time and frequency adjacent workers are exposed. For example, although passing through a contaminated area on the way to perform non-asbestos related activities is technically work which exposes employees to asbestos, the competent person's evaluation properly may conclude that no appreciable exposure is possible because of the brevity of the "work" in the area.

(5) Regulated Areas

Paragraph (e) General Industry, Construction and Shipyard Employment Standards. Regulated areas are a traditional component of OSHA health standards. They segregate both the work and the worker so as to better regulate the work, and to protect uninvolved employees from exposure. The 1986 standards required regulated areas for work above the PELs and in construction, for demolition, renovation and removal activities. The final standards require that regulated areas be established where the PELS are likely to be exceeded, and under the construction and shipyard employment standards, where Class I, II and III asbestos work is performed. These requirements are substantively similar to those proposed in 1990.

The basic requirements of the regulated areas are the same for all three standards, They are changed from the current standard to more coherently reflect the rest of the standard's provisions. For example, paragraph (e)(2) which requires the regulated area to be "demarcated to minimize the number of persons within the area, and to protect persons outside the area from exposure to airborne concentrations of asbestos" has been changed in two ways. The phrase "in any manner," has been deleted. Since, paragraph (g) requires critical barriers for Class I and II work, and paragraph (k) requires warning signs outside regulated areas, demarcation must incorporate barriers and signs where otherwise required.

OSHA has also deleted the phrase "in excess of the TWA and/or excursion limit" in the construction and shipyard employment standards to describe the level of protection intended to be offered persons outside the regulated area. Since OSHA has determined that a still significant risk remains below the PELS, intended protection should not be limited to protecting down to these levels. OSHA noted in its 1990 proposal that in the construction standard, "the regulated area controls are proposed to apply even when exposures may be less than the newly proposed PEL of 0.1 f/cc" (55 FR at 29716), however, no change was proposed for the "demarcation" provision. Paragraph (e)(3) is unchanged and continues to limit access to regulated areas to "authorized persons."

The final regulated area requirements for construction and shipyard industry delete former and proposed (e)(6), which dictated when negative pressure enclosures (NPEs) must be erected, and various duties required of the "competent persons" to ensure integrity of the regulated area and enclosure. Under OSHA's former approach, negative pressure enclosures were, in many cases, how construction employers should have demarcated their regulated areas. OSHA focused on the role of such enclosures in providing "bystander protection." In these final standards, OSHA is repositioning the NPE provisions to paragraph (g), "methods of compliance." There, these systems are required to reduce exposures of the employees who are disturbing the asbestos who are inside the enclosures, as well as employees outside the enclosure.

(6) Exposure Assessment and Monitoring

Paragraph (d) General Industry. There are no changes to the exposure monitoring provisions of the General Industry Standard.

Paragraph (f) Construction and Shipyard Employment Standard. To conform with the newly revised approach to categorization of asbestos work, and to reflect the difficulties of reliably estimating asbestos exposures based on limited past or current exposure monitoring, the requirements for exposure monitoring in the 1986 standard have been changed. First, there is a general requirement that all employers who have a workplace covered by this standard conduct an "initial exposure assessment" at the beginning of each asbestos job [(paragraph (f)(2)]. Exceptions to this requirement exist only for most Class IV work. The "assessment" must be conducted by the "competent person." The purposes of these "assessments" are to predict whether exposure levels during the planned asbestos work can be expected to exceed the PELs, and thus whether additional monitoring, and other precautions are required.

"Initial assessments" are different from "initial monitoring" required in the 1986 standards. "Initial monitoring" as used for processes in general industry, was rationally relied on to estimate future exposures for that purpose. Historic monitoring data were considered second-best data. The new requirement for "initial exposure assessments" acknowledges that initial exposure monitoring in many cases cannot adequately predict all future exposures on construction jobs. Even if monitoring results were instantaneously available, the value of early exposure monitoring in predicting later exposures over a multi-day asbestos job is limited. First-day exposures are likely to be lower than later exposures, because they reflect early set-up rather than removal activities, conducted in relatively clean areas before disturbance may contaminate the regulated area.

One purpose of the initial exposure assessment is to identify which asbestos jobs are likely to exceed the PEL in time for employers to install and implement the extra controls required to reduce such exposures. Such additional controls may consist of ventilation which redirects the air away from the over-exposed employees, and mandatory protective clothing and hygiene facilities associated with donning and removing such gear. Even employers who are planning to install full negative pressure enclosures with air flushing technology must conduct initial exposure assessments. This will insure that the "competent person" has reviewed the success of controls in past projects, in order to evaluate the planned controls for the current project. Testimony and comment to the record emphasized that the evaluation of industrial hygienists or other properly trained personnel was essential to decision making on how best to protect workers. For example, David Kirby of Oak Ridge National Laboratory, agreed with the statement that before there is any operation involving asbestos containing material, the industrial hygiene staff makes a determination as to whether that's likely to be a high risk, relatively high risk or a low risk operation (Tr. 197). Other participants endorsed requiring advance assessment of asbestos-disturbing jobs (see e.g., ORC, Ex. 145, p. 6).

The former "initial monitoring" provisions allowed use of historic data. OSHA now requires the evaluation of data from earlier asbestos jobs to estimate exposures on new jobs. However, the "data" reviewed are more than air monitoring results. This record has convinced the Agency that consideration of factors in successfully controlling asbestos exposures needs to be a part of the assessment. In addition to measurement results, the assessment must review relevant controls and conditions, factors that influence the degree of exposure. These include, but are not limited to, the degree and quality of supervision and of employee training, techniques used for wetting the ACM in the various circumstances encountered, placing and repositioning the ventilation equipment, and impacts due to weather conditions. The assessment therefore must be based on the competent person's review of all aspects of the employer's performance doing similar jobs. Only if similar controls are used and the work supervised by the same or similarly trained personnel, may past data be relied on. In addition, the results of initial monitoring required if feasible, must inform the competent person's assessment. Judgment of the "competent person" is required when reviewing records of past work. For example, even where an employer's earlier glove bag removals produced some exposures above the PEL, if more recent glove bag removals by the same crew show no exceedances, the "competent person" may be warranted in predicting that the current job performed by the same crew will be well controlled and exposures will not exceed the PELs.

The other basis allowed for an initial exposure assessment is "objective data" to show that it is, in effect, impossible for a job to result in excessive exposures. The 1986 standard, 1926.58, paragraph (f)(2)(ii), allowed such data to demonstrate that the "product or material containing asbestos cannot release * * * (excessive) concentrations * * *." Since the record of this proceeding shows that almost all asbestos products may in time become hazardous, if for example, their matrix becomes disturbed, the activity, as well as the material, is the exposure-limiting factor. OSHA therefore now allows a showing that a specific activity involving a product is incapable of producing exceedances. The "objective data" must demonstrate that under "the work conditions having the greatest potential for releasing asbestos," an activity coupled with a specific material, simply cannot result in excessive concentrations.

OSHA cannot predict all the combinations of activity and product which will meet this test. OSHA believes instead that construction employers should be given the responsibility for making these determinations for their particular work. However, on the record of this proceeding, they would appear to be limited to Class IV activities, or certain Class III activities such as limited removal of intact asbestos containing gaskets using wet methods and containment methods. OSHA notes that under no conditions can a Class I removal qualify for this exemption; based on the record of this rulemaking, every removal activity involving TSI and surfacing ACM is capable of releasing fibers above the PEL.

There are separate provisions regarding a "negative initial exposure assessment" which is a demonstration that the activity involving the asbestos material is unlikely under all foreseeable conditions to result in concentrations above the PELs.

The competent person must exercise judgment in performing these exposure assessments. For example, if initial monitoring is evaluated the first day's measurements which reflect set-up activities may not adequately predict later exposures on a removal job. The competent person should examine both the first day's exposures and comparable full job exposure data from other comparable jobs, before a conclusion is reached that exposures on that job will not exceed the PELs.

In large measure, the required bases for making a "negative exposure assessment" in the revised construction standard are the same criteria which would, under the 1986 standard, have allowed an employer to claim an exemption from initial monitoring based on "historic data." The standard makes it more difficult to base an initial exposure assessment on historic data than did the previous provision for initial determination. Now, the assessment must consider, the experience and training of the crews. Therefore, the standard now requires that a negative exposure assessment must compare crews with comparable experience and training, an employer cannot compare untrained and inexperienced crews. And no "negative exposure assessment" can be made if the crews which disturb asbestos in the current job are untrained. OSHA believes that a major factor in the effectiveness of all control systems for removing asbestos-containing materials is the experience and training of the contractor and employees. Evidence in the record shows dramatic reductions in exposure levels as untrained employees learned proper glove bag techniques (see e.g., the NIOSH study, Ex. 125).

The lack of a "negative exposure determination" usually indicates that workers are not experienced/trained or that a job is complex. In such situations, additional protections, less dependent on experience of the workers, or the complexity of the job, should be required. Thus, critical barriers are required in all Class I and II work, and for Class III work, plastic barriers are required, where negative exposure assessments are not produced. If the employer cannot assure that levels will be minimized, protection against migration of asbestos dust must be provided. Similarly, if excessive levels are possible, employees in all classes must be protected by respirator use and the standard so requires.

OSHA believes its approach balances the concern that asbestos exposure levels vary from job to job and may be non-predictive of future levels with the Agency's knowledge gained from long-term enforcement of the asbestos standard, that different employers have different "track records." The negative initial exposure assessment provisions require consideration of factors which have been identified as influencing the variability of results. In fact, one commenter stated that "* * * it is invalid to predict that any particular operation is always below the PEL," identified critical contributing variables as "the materials, work practices and experience of the crew" (Ex. 7-52). OSHA is requiring the "negative exposure assessment" to be based on these, among other, factors. OSHA emphasizes that a "negative exposure assessment" does not predict exposure levels beyond a particular job. A new assessment must be produced each time another job is undertaken. Employers may evaluate repetitive operations with highly similar characteristics, as one job, such as cable pulling in the same building, so long as the historic data used also reflect repetitive operations of the same duration and frequency.

In sum, OSHA believes data specific to the building, contractor and employees is helpful in predicting exposures when the same variables apply. The lack of such data should require additional precautions. Additionally, unless there is a "negative exposure assessment," the employer must continue to conduct periodic monitoring. Periodic monitoring, in a change from the 1986 construction standard, now is required within the regulated areas of Class I and Class II asbestos jobs and for Class III asbestos work where the initial assessment projects that the PEL is reasonably likely to be exceeded. In these operations the employer is to perform daily monitoring representative of the exposure of each workers performing these tasks. The provisions allowing discontinuance of monitoring, additional monitoring, observation of monitoring are unchanged.

Although not a remanded issue, several participants discussed the subject of a clearance fiber level to determine when a regulated area could be reoccupied following asbestos operations. Some supported use of a clearance level with aggressive sampling and analysis in accredited laboratories (Ex. 141, 143). Most who supported a clearance level stated support for the AHERA level of 0.01 f/cc or background fiber level (40 CFR 736.90). A representative of the US Navy felt that measurement of the quality of abatement -- a clearance level -- was needed, but that it should not be considered to be a "health standard" (Ex. 7-52). In a similar vein, the Resilient Floor Covering Institute (Ex. 147, Tr. 279) and a representative of the American Paper Institute pointed out that a permissible exposure limit and a clearance level are not the same and should not be confused; the former is health-based and the latter a measure of cleanliness (Ex. 7-74). Mr. Churchill an asbestos consultant, supported a clearance requirement and felt that the person performing this measurement should be an independent entity (Ex. 7-95). As mentioned earlier, the Shipyard Employment Standards Advisory Committee recommended adoption of a clearance level of 0.04 f/ cc measured non-aggressively (Ex. 7-77). The submission of the Monsanto Company expressed their desire that OSHA not adopt a clearance requirement (Ex. 7-125).

OSHA has not included a provision for a specific "clearance level" in these revised standards. In reviewing the record, there is no clear evidence of a linkage between such a requirement and subsequent lessening of worker exposure. Clearly, regulated areas must be cleaned following asbestos work. However, designation of a specific fiber level which must be attained before an area can be reoccupied does not appear to be necessary for worker health when all other provisions of the standard are complied with. Meeting the requirements of the standards will protect workers and bystander employees and will prevent the migration of fibers from the work area. The docket contains some data indicating that attainment of a clearance level (either background or 0.01 f/cc) does not conclusively predict fiber levels which will occur in formerly regulated areas (Ex. 1-23, 162-19). Therefore, OSHA has not included a quantitative cutoff to determine whether a work area has been adequately cleaned to allow re-entry, rather the standards now require that the information regarding the final monitoring of the prior work be provided to those reoccupying the area. However, OSHA recognizes the need for adequate cleaning of the worksite following disturbance/removal of asbestos.

(7) Methods of Compliance

Paragraph (f) General Industry. OSHA proposed several changes to the methods of compliance provisions.

One was to require specific work practice and engineering controls for brake and clutch repair; another was to regulate the maintenance of asbestos-containing flooring by prohibiting certain kinds of work practices and requiring others; the third was to require that engineering and work practice controls to achieve the newly reduced PEL of 0.1 f/cc be phased-in to coincide with the imposition of the EPA ban for various industrial sectors which manufacture asbestos containing material (see 55 FR 29721-29726). The final general industry standard retains the conceptual outline of these proposed changes; however the details differ.

Brake and Clutch Repair

OSHA is adding a mandatory appendix to its asbestos standard for general industry and to the shipyard employment standard. This appendix specifies the engineering controls and work practices to be followed during brake and clutch work. Two methods of control are "preferred," the enclosure/HEPA vacuum method and the low pressure/recycle method. In operations in which such work is infrequent (i.e., establishments performing fewer than 5 brake jobs per week), simple wet methods are included among the "preferred" controls. Also, use of "equivalent" methods of control is permitted.

In the July 20, 1990 proposed revision of the general industry asbestos standard, OSHA proposed that the employer comply with the standard by implementing one of three specified methods of engineering controls and work practices to control asbestos exposure during automotive brake and clutch repair and assembly operations. These methods were the enclosed cylinder/HEPA vacuum system, the spray can/ solvent system, and the wet brush-recycle method. Detailed requirements for these three methods were set out in proposed Appendix F. Once having properly used one of these methods, the employer would have been exempt from other requirements of the standard. OSHA preliminarily found that the use of these methods would routinely result in exposure levels below the PEL. The proposal also would have allowed the employer to comply with the standard by using an "equivalent" method, which follows written procedures, which the employer demonstrates can achieve results equivalent to Method A, [the enclosed cylinder/HEPA vacuum system, Proposed 1910.1001 (f)(x)]. This proposed revision differed from the 1986 standard in two ways. The earlier standard set out two methods of reducing exposure in a non-mandatory appendix. Secondly, the controls themselves are somewhat different; one method, the wet brush-recycle method, was added; the enclosed cylinder/HEPA vacuum system was revised, and the spray can/solvent system is retained. OSHA endorsed these three methods based primarily on the results of a NIOSH study completed after the 1986 standard which found that all three methods effectively reduced exposure levels during brake drum servicing operations to below the proposed PEL of 0.1 f/cc (Ex. 1-112).

In the final standard OSHA lists two "preferred methods," the wet-brush recycle methods and the enclosure/HEPA vacuum system. OSHA is deleting the solvent/spray method from the list of preferred methods. OSHA still is listing the above two methods as "preferred," but the description of these methods is more generic than in the proposal, so as not to preclude use of methods which differ from those described in the proposal in minor ways which are unlikely to affect their efficiency. In addition, specific training provisions are added to ensure that work practices are effectively followed.

Like the proposal, "equivalent" methods are allowed so long as required training is held. The employer must show that the "equivalent" method can reliably achieve exposures below the PEL in the workplace conditions where the method is sought to be used. In addition employers using such "equivalent" methods must demonstrate by exposure data from their workplaces using the equivalent method, or by reference to exposure data representing conditions similar to their workplace that the anticipated exposure reduction in fact, has been achieved. OSHA believes that these changes will allow employers to choose among various proven approaches and encourage the development of new devices and practices which effectively reduce exposures in brake and clutch repair facilities.

Considerable comment and testimony were submitted to the record by the public concerning OSHA's proposed revisions on protection for automotive repair workers. Information concerning additional methods to achieve asbestos control during brake repair was submitted. These additional methods include HEPA vacuum systems without an enclosed cylinder (Ex. 7-104), using water spray instead of solvent spray (Ex. 7-104, 7-04), enclosures shaped other than cylindrically (Ex. 7-127), and collecting the drips of sprays from the solvent spray method (Ex. 1-84).

Some commenters claimed that OSHA should not require any specific method of reducing airborne asbestos exposure to brake and clutch repair workers, but merely require that the PEL be achieved (Ex. 7-31, 7-43, 7-79, 7-104, 7-146). Other commenters pointed out that most brake service operations are performed by small businesses that lack resources to evaluate control devices (Ex. 1-112). Evidence submitted concerning the airborne asbestos fiber levels produced by the use of most of the suggested methods showed exposures consistently below the proposed PEL of 0.1 f/cc.

Various comments concerned the "wet brush-recycle method." A developer of an enclosure method for brake/clutch repair asbestos control, recommended that the term be broadened to allow "more latitude in design preference for the manufacturer" (Ex. 162-41). He suggested that the name be changed to "low pressure/wet cleaning" method. He also asked that OSHA use a more general term to describe the preferred enclosure method, objecting to specification of its shape as cylindrical. OSHA agrees that the shape of the enclosure need not be specified and that the term suggested, "negative pressure enclosure/ HEPA vacuum system," was appropriate.

Similarly, R. Wagner of BP of America felt that it was not necessary that the wet brush/recycle method actually include a brush and presented monitoring results indicating effective fiber control when spraying on the solution without brushing (Ex. 7-24). OSHA agrees that, although a brush is useful in cleaning the components, the preferred method will be designated low pressure/wet cleaning and will not specify the use of a brush.

A manufacturer of a low pressure/wet cleaning apparatus, objected to OSHA requiring use of an aqueous solution in the machine (Ex. 162-1). OSHA understands that the organic solution in the apparatus is a degreaser used as a parts cleaner. Mr. Swartz in testimony explained that solvents are used as degreasers, but that most brake work does not require degreasing -- he estimated that only once per 200 to 300 brake jobs would such a solvent be needed (Tr. 1843). OSHA has determined that it will maintain the requirement that aqueous solutions be used in this procedure to control asbestos fiber levels. OSHA further warns of the potential danger of solvent use in these operations and that use of solvents, which are often flammable and may be carcinogenic, must be undertaken with great care. OSHA also stresses the need for low pressure application of the solution to the surfaces during this operation to avoid asbestos fiber release and the necessity that the asbestos-contaminated solution not be allowed to dry on surfaces.

A manufacturer of a wet brush-recycle type brake cleaner, Hilgren of Kleer Flo, offered the following advice to users of this method regarding disposal of waste: "Our recommended method of disposal is to simply add adsorbent material such as "floor-dry" to the waste bag. Then direct the flow through brush into the bag containing the absorbent material. Allow the machine to pump the solution from the reservoir" (Ex. 7-117).

Most relevant comments supported the effectiveness of two of the three proposed "preferred" methods: the enclosure/HEPA vacuum method and the wet wash/recycle system. However, substantial opposition was directed at OSHA's preference for the solvent spray system. For example, George Swartz, Director of Safety for Midas International Corporation testified that "the utilization of an aerosol system is ludicrous" (Tr. 1840). One, some of the solvents used in commercial preparations are suspect carcinogens. Two, use of a spray can does not reliably control exposures due to asbestos dust in the brake assembly, because of the difficulties of removing the drum, and that after removal asbestos containing dust in the assembly cannot easily be reached by a aerosolized spray. Three, certain solvent sprays, according to Mr. Swartz, can damage friction material and the rubber parts of the cups which force the brake shoe out to the drum (Tr.1840-46). Another witness, James E. Clayton, testified that "you can't take a can of compressed solution like this (Gunk brake cleaner) and just spray it on dry dust without it getting into the air." (id at 1914-15).

The National Automobile Dealers Association (NADA) agreed in its post-hearing comment that the use of spray can with certain solvents is potentially dangerous, and suggested that nonhazardous sprays or aerosols be allowed (Ex. 150). Another participant described an occasion in which the spray can was accidentally dropped, punctured, and released solvent into the work area (Ex. 7-24). The safety director at Fruehauf Trailer Operations, asked "why is it necessary to use a solvent as opposed to water? * * * why couldn't it be used in place of a solvent in the performance of brake and clutch work?" (Ex. 7-4). Mr. Swartz agreed that "simple water and detergent can be as effective" (Ex. 1-176) However, he insisted that it be a gentle mist of water and that resulting drips be caught and proper disposal carried out (Tr. 1852).

OSHA agrees with these comments and witnesses. The Agency notes that some of the solvents contained in the spray cans used to spray brake assemblies present significant health risks. As a matter of public health policy, it is better not to list as preferred, a compliance method which introduces another hazardous substance into the breathing zone of the worker.

Further, the effectiveness of the solvent/spray method is compromised by the reported need to use additional force to remove asbestos deposited in the brake assembly, which the spray cannot reach. Additionally, comment and testimony indicate that the force of the aerosol spray by itself can make airborne the asbestos-containing dust. OSHA noted in the proposal, that the spray/solvent can method produced the highest airborne concentrations of the methods tested by NIOSH (55 FR at 29724). OSHA notes that although it based its endorsement of the solvent/spray method on the NIOSH study, as Mr. Swartz pointed out, "the issue of the residual dust left in a drum, I don't think, was properly addressed in that study * * * (In) the real world, * * * the mechanic will either dump it on the ground or he'll dump it in a garbage can. At the end of the day he's going to sweep the floor, and he's sweeping the dust up" (Id at 1845).

Thus, in this final standard the spray/solvent can method is no longer a "preferred method," the use of which will exempt employers from other provisions of the standard. Although the standard does not prohibit the use of solvent sprays in brake and clutch repair to control asbestos exposure, employers will have to comply with other provisions in the asbestos and other standards when using the method. Initial monitoring must be undertaken to assure that exposures are likely to remain under the PEL, provisions of the hazard communication standard relating to communicating the hazard potential of the solvent used, and training employees in avoiding exposure to such solvent must be complied with. Employees must be specifically informed that the solvent/spray method is not preferred, and OSHA's reasons for that decision must be explained to them, as part of that training. Employers must provide for the prompt cleanup of all asbestos containing liquid or debris which is produced by any brake cleaning method, including a solvent/spray. Thus, solvent-wetted asbestos containing material must be HEPA vacuumed when it reaches the ground, because waiting will result in dried and airborne dust.

Among the methods tested by NIOSH was the use of a HEPA vacuum alone, without enclosure. The National Automobile Dealers Association representative, D. Greenhaus, encouraged OSHA to include this in its list of preferred methods of asbestos control in brake work stating that this was the method already in use in many places (Ex. 7-104). The Sheehy (NIOSH) study noted that" * * * the drums must be removed before the vacuum cleaner can be used, thus there is a potential for asbestos release during drum removal" (Ex. 1-112), and P. Carpenter of Nilfisk stated "[t]he greatest potential for exposure occurs when the brake drum is first removed" (Ex. 7-140). OSHA agrees that the potential for exposure during drum removal before the HEPA vacuum can be used precludes listing including this as a preferred method. Moreover, NIOSH found that HEPA systems alone do not clean the brake components as effectively as the other methods (Ex. 1-112). Mr. Greenhaus also recommended that OSHA prohibit three activities during brake operations: dry brushing, air hose cleaning and use of non-HEPA vacuums. NIOSH agreed that such prohibitions are necessary and OSHA concurs.

One related issue is whether to require respirator use for employees when changing filters or bags from vacuums. OSHA proposed that they not be required when changing HEPA filters, noting that filter changes occurred infrequently, recorded fiber levels during changes were not excessive, and other requirements triggered by respirator use, such as medical examinations and fit testing procedures, did not appear to confer any significant benefit to employees. One participant, Mr. Clayton, who initially disagreed with OSHA's proposal not to require respirators for filter changes, clarified that the ancillary requirements for a respirator program, "would scare everybody away from wanting to do it * * * and would be a rather heavy burden for most employers" (Tr. 1931). Mr. Clayton pointed out that exposure potential existed not only during filter changes, but during vacuum bag changes as well. He further pointed out that although HEPA filter changes were infrequent, bags "could be changed as often as every three to five weeks by a shop" (Id at 1929). Mr. Clayton described two systems of ensuring that bag changing does not expose employees to asbestos containing dust. Under one system the bag is collected under negative pressure; under the other the bag is made from non-woven material and is "virtually undestructible." OSHA has concluded that so long as filters and vacuum bags are changed using work practices to minimize rupture and spillage, exposure from that activity will be de minimis, and respirator use is not required to protect employees. Accordingly, additional work practices relating to filter changes, when a vacuum is used, are included in the standard.

OSHA is allowing another method to be used in shops in which brake work comprises only a minor portion of the workload, and thus where employee exposure is infrequent and minimal. For those shops in which brake work is infrequent, OSHA has determined to allow the use of a wet method of control as a "preferred" method. Therefore, in facilities in which no more than 5 pairs of brakes or 5 clutches, or some combination totaling 5, are repaired each week, the mechanic/technician may control potential asbestos exposure through the use of a pump sprayer (bottle) containing water or amended water to wet down the drum or clutch housing before it is removed and to control fiber release during subsequent activities. The mechanic may use other implements to deliver the water such as a garden hose; however, the resulting waste water generated must be caught and properly disposed of without allowing it to dry on any surfaces. OSHA anticipates that the use of a spray bottle will be adequate to control the dust without generating a large volume of waste water, however any waste water generated must be disposed of properly. OSHA applied a qualitative analysis using its risk management expertise in making the decision that allows less effective controls for facilities that do 5 or fewer brake and 5 or fewer clutch repair jobs per week. Relevant factors were the magnitude of the risk of asbestos caused disease estimated in the 1986 risk assessment at levels of exposure in vehicle repair facilities, the duration of exposure, and the practicality of using controls in the industry.

In describing the usual work practices of mechanics performing brake jobs, Mr. Swartz of Midas Corporation reported that it was occasionally necessary for the mechanic/technician to dislodge a "frozen" brake drum; this was usually performed by striking it with a hammer (Ex. 1-176). When performed within an enclosure under negative pressure, this operation would be unlikely to expose the worker to asbestos fibers; however, when using the other methods it is essential that the exterior of the drum, especially around the seams, be thoroughly wetted to minimize fiber release. OSHA concurs and thus will require that before attempts are made to dislodge a "frozen" brake drum, the drum must be thoroughly wetted.

Other comments were received which dealt with minor alterations in wording which would render the requirements clearer and more specific and some of these have been incorporated into the language of Appendix F (Appendix L in the shipyard employment standard). Several participants noted that additional activities, such as inspection and disassembly of brakes could also result in exposure and should be included. Mr. Swartz explained that brakes are frequently checked to determine whether they are defective and this involves removal of the drums and results in potential exposure to asbestos-containing dust (Tr. 1843). OSHA agrees that these activities should be covered by the rule and has included them in the language of the final rule. Therefore the following activities will be listed and will require implementation of the provisions of the mandatory appendix F (appendix L in the shipyard employment standard): clutch and brake inspection, disassembly, repair and assembly.

Mr. Swartz also testified that brake shoes are recycled and new friction material is placed on re-used metal frames (Tr. 1871). A letter forwarded to OSHA by EPA Brian Putnam, whose work experience included 4 years of delivering auto parts to garages and service stations, stated:

* * * it is my observation that auto parts employees face significant exposure to asbestos from brake shoe cores, brake drums, and clutches. Not only do they store cores for exchange with the manufacturers, most also turn brake drums which come in with a * * * coating of dust on them (Ex. 1-133).

The asbestos standard 1910.1001(k)(1) states that "all surfaces shall be maintained as free as practicable of accumulations of dusts and waste containing asbestos," and subsequently in (k)(6) specifically states that items consigned for disposal which are contaminated shall be sealed in impermeable bags or other closed impermeable containers. In order to include materials which are contaminated and scheduled for recycling, not disposal, the phrase "or recycling" is added to this provision (k)(6), which now is as follows: Waste, scrap, debris, bags, containers, equipment and clothing contaminating with asbestos consigned for disposal or recycling, shall be collected and disposed of in sealed impermeable bags, or other closed, impermeable containers.

Engineering controls and good work practices should be implemented at all times during brake servicing. Because of the health hazards associated with asbestos exposure, these actions must be considered even when the worker believes that the brake shoes do not contain asbestos.

OSHA received several comments pointing out a need for training requirements for brake and clutch mechanics. For example J. Clayton of Clayton Associates, Inc supported a training requirement for brake and clutch repair workers citing as examples that New Jersey required one day training for mechanics and that Maryland requires training for those covered under its asbestos program. He estimated the cost of training at $150 and noted that certified instructors were required in both these states (Ex. 7-127). OSHA agrees that workers exposed to asbestos must be trained in appropriate ways to avoid exposure to airborne asbestos fibers. Therefore, OSHA has provided a mandatory appendix outlining the work practices to be used in performing these operations, and has included a requirement that brake and clutch repair workers receive training in the appropriate use of these work practices.

Floor Maintenance

Paragraph (k)(7) General Industry Standard. The 1986 standard contained no provisions specifically covering work practices on asbestos containing flooring materials. In 1990, OSHA proposed in paragraph (f)(xi) several limitations on buffing and sanding asbestos containing flooring. In the housekeeping section of the final OSHA is prohibiting or limiting three work practices relating to floor maintenance for asbestos-containing flooring materials and those assumed to contain asbestos. They are: (i) sanding of asbestos-containing floor material is prohibited; (ii) stripping of finishes shall be conducted using low abrasion pads at speed lower than 300 rpm and wet methods; and, (iii) burnishing or dry buffing may be performed only on asbestos-containing flooring which has sufficient finish so that the pad cannot contact the asbestos-containing material.

OSHA had proposed to allow asbestos containing floor tile to be buffed only with "low abrasion pads at speeds of 190 rpm or less" (See 55 FR at 22752). However, after a review of the record OSHA believes that restricting sanding of floor materials, limiting the speed and abrasiveness of the pads and specifying use of wet methods for stripping floors, and allowing buffing only on finished floors will protect floor care workers from exposure to airborne asbestos fibers while performing the maintenance and will minimize future exposures due to deteriorating flooring caused by inadequate maintenance.

Paragraph (g) Construction and Shipyard Employment Standards:

The "methods of compliance" provisions are the core of the revised standards. They set generic, operation-specific and exposure triggered requirements for conducting asbestos work. In the 1986 construction standard, provisions dictating engineering controls and work practices for most construction jobs were contained in paragraph (e), governing the "regulated area." OSHA believes that paragraph (g), the methods of compliance section, is a more logical home for these provisions.

Most of the requirements in paragraph (g) are instructions to use specified work practices. The work practice approach to controlling asbestos exposure in construction activities is widely endorsed. It is the model for NESHAP regulation under EPA (see 40 CFR 60.143), most state regulations and voluntary consensus guidelines. OSHA has tried to formulate work practice requirements as simple, flexible instructions, embodying the basic control strategies for asbestos dust suppression. These are to wet it down, contain the disturbance, and isolate the operation. The work practice-engineering controls which are listed and described in the regulation are the ones which the rulemaking record confirms are used, understood, and effective.

OSHA expects that modifications and innovations in asbestos control technology will be developed. The standards provide for this by setting up general criteria for alternative controls, and an easily met procedure to allow the use of effective alternatives. Paragraph (g)(6) governs alternatives for Class I control methods, and paragraph (g)(7)(vi) for Class II methods. For both classes, detailed written demonstrations of the effectiveness of the alternative/modification are required and evaluations by designated persons are required. Alternatives for Class I work require a more rigorous demonstration of effectiveness, and advance notice to OSHA of their use. OSHA intends these requirements to be capable of being met by well-designed and tested alternative control methods. They are meant to exclude short-cut methods which hope to evade the other provisions in the standard. By their inclusion, OSHA is stating its policy view that industry has demonstrated its responsible innovative capability in the past, and will continue to do so.

The first provision in the construction methods of compliance paragraph, (g)(1)(i), requires that three basic and simple controls be utilized in all operations covered by the construction standard, regardless of exposure levels in those operations. These provisions apply to, for example, employers who install asbestos-containing material (no Class designation), clean up asbestos-containing debris at a construction site (Class IV), repair a boiler covered with asbestos-containing TSI (Class I or III), and remove asbestos-containing surfacing material (Class I).

The controls required are: use of HEPA filtered vacuums to collect debris and visible dust; use of wet methods to control asbestos fiber dispersion; and prompt disposal of asbestos contaminated waste materials.

OSHA has imposed these controls to reduce airborne contamination by asbestos fibers disturbed during construction activities. However fibers are released, contamination can be reduced by suppressing asbestos containing dusts, and/or collecting them before they dry and are able to migrate.

OSHA believes that most employers will be able to use wet methods, in handling asbestos-containing materials to reduce the airborne migration of fibers. The use of wet methods to control airborne asbestos was not explicitly required in the 1986 construction standard. It was mentioned among the control measures which could be used to keep down fiber levels during "maintenance and renovation projects in environments that do not lend themselves to the construction of negative-pressure enclosures" (51 FR 22711). In the Method of Compliance section, OSHA presented use of wet methods among a list of engineering and work practice controls from which an employer could choose when seeking to comply with the PEL. The 1972 asbestos standard had required the use of wet methods to the extent practicable to reduce the release of asbestos fibers unless the usefulness of the product would be diminished by the use of such methods. On reconsideration, OSHA now finds the use of wet methods to be an inexpensive, generally feasible, and highly effective way to control release of asbestos fibers and returns to the earlier requirement for its use in all feasible situations.

There is overwhelming record support for the use of wet methods (e.g., Exs. 7-1, 7-34, 7-37, 7-51, 7-52, 7-74, 7-86, 7-89, 7-99, 7-132, 119P, 143, Tr. 223, 722 and 756). Representatives of most sectors, expressed support for a requirement for wet methods.(e.g., transite panel removal, Ex.7-74; removal of asbestos packing, Ex. 7-99; floor tile maintenance, Ex 7-132; custodial or maintenance work, Ex. 162-4, 162-25; floor tile and sheet removal, Ex 7-132; sheet gasket removal, Ex 119; cutting of transite pipe, Ex.117, Tab 6 at 5, Tab 7 at 1). B. Kynock of the AIR Coalition endorsed the use of wet methods, stating: "wetting of material is still considered a state of the art engineering control -- using wet methods -- because it is the one definitive way we can keep fiber levels to a minimum" (Tr. 3574). Evidence submitted into the record concerning a variety of asbestos jobs showed significant decreases in exposure levels when wet methods were used, compared to when the work was done dry [see e.g., re: sheet gasket removal (Ex.119-P)]. In the study by Paik et al, 1982 (Ex. 84-204) sprayed-on asbestos containing material was removed from eleven buildings, in one dry methods were employed due to electrical considerations while wet methods were employed in the other buildings. The dry method resulted in a geometric mean fiber level of 16.4 f/cc, while during the use of wet methods the geometric mean was 0.5 f/cc. OSHA notes that the OSHA PEL at the time the samples were taken was 2.0 f/cc.

Exxon (EUSA) submitted extensive sampling data indicating low fiber counts during outdoor removals in which wet methods were used (Ex. 38). Exxon also submitted sampling data from the outdoor removal of pipeline wrap from underground lines in which wetting was the primary means of control and in which 30 personal samples had an average fiber level less than 0.03 f/cc (Ex. 127). It is noted that Exxon also submitted specific additional work practices used in conjunction with wet methods to control fiber levels.

Requiring wet methods is consistent with EPA's regulatory scheme. Wet methods are required by EPA for removal and demolition jobs falling within the jurisdictional limits of NESHAP, and are recommended by that Agency as part of a basic "O&M" program for building custodians and maintenance workers. (EPA, Managing Asbestos In Place, Ex. 1-183, p. 18-19).

EPA/NESHAP, which requires facility owners and/or operators to control asbestos fiber emissions by wetting prior, to during, and after demolition/removal, has provided guidance in a pamphlet entitled "Asbestos/NESHAP Adequately Wet Guidance" (EPA 340/1-90-019, December 1990, Ex. 1-300). In this booklet two exceptions to wetting are described: when temperature at the point of wetting if below freezing, and, when use of water would unavoidably damage equipment or present a safety hazard. In the latter case, local exhaust ventilation and collection systems to capture fibers must be used.

Others voiced reservation regarding a universal requirement for use of wet methods. E. Downey of US West, Inc. felt that in the case of telecommunications industry and computer systems, use of wet methods would not be practical, particularly in roofing operations (Ex. 7-79). J. Collins of the US Navy Office of Operations and others recommended ground fault circuit use for avoiding the electrical hazards presented by use of wet methods (Ex. 7-52).

OSHA will allow employers to claim infeasibility if they cannot use wet methods due to conditions such as electrical hazards, hot surfaces, and the presence of technical equipment which cannot tolerate moisture.

The use of wet methods for roofing was a major issue in this proceeding. Steven Phillips, counsel to the National Roofing Contractors Association testified:

We have submitted for the record a report performed by SRI * * * their recommendation was that there is no improvement on asbestos emissions and there are safety hazards involved in putting workers on roofs when wet methods are utilized * * * (Tr. 2456).

The National Roofing Contractor's Association (NRCA) cited four reasons not to require wetting on roofs: "the introduction of water on the roof creates safety hazards, such as slipping; water on the roof can enter the building and cause damage and electrical hazards; the introduction of water on the roof can damage the roof system (e.g., by soaking insulation boards); the SRI International study reveals that roofing work involving wetting does not appear to produce either higher or lower concentrations than work performed dry. We believe this is because of the nature of roof systems. They are applied and in place to repel water. Thus, water (amended or unamended) does not penetrate the material -- it just rolls off of it" (Ex. 7-112, p. 21).

Some participants suggested that using wet methods on roofs should be recommended, but not required, because of safety concerns. For instance, the asbestos administrator for Florida, noted that using wet methods on a sloped roof may be more of a hazard to the workers, than the benefits gained (Ex. 7-6).

In contrast, NIOSH recommended that before an operation (tear-off of asbestos-containing roofing material), the roof should be wetted with water or other wetting agent (Ex. 44). BCTD noted in its post-hearing brief that "the majority of the jobs reported in the SRI Study, submitted by NRCA, employed wet methods" (Ex. 143, citing Ex. 9-31A). Various submissions noted that power cutting of built-up roofing is the standard method used to remove roofing material. Use of this method generates dust which may contain asbestos (Ex. 1-357, 7-95, 7-96, 7-115). The Paik study and other evidence demonstrate that wetting does substantially reduce exposure. OSHA believes that continuous misting of the cutting blade during the cutting operation, whether performed by hand or by machine will help to control dust. Field observations of such procedures have shown that little water is pooled as a result of the misting process (Ex. 1-313), and that in most circumstances, evaporation will quickly occur. Therefore, OSHA does not believe that the requirement to mist the cutting blade will create a slipping hazard on roofs under most circumstances. If, however, a competent person determines that the specific conditions of a roofing job (e.g. a steeply sloping roof, or below freezing temperatures) combined with the water resulting from any misting, would create a slipping hazard, misting may be omitted, if other precautions are followed, such as equipping the power tool with a HEPA vacuum system, or using hand methods.

The National Roofing Contractors Association said that currently there is no HEPA vacuum attached roofing cutter (Ex. 146). However, a wide variety of power tools have been fitted with local exhaust systems that work very well, including those used on tools for asbestos work. The 1972 asbestos standard required the use of local exhaust ventilation on all hand-operated or powered tools which may produce or release asbestos fibers in excess of the permissible exposure limit (37 FR 11320). The 1986 standard affirmed the requirement for ventilation for tools (51 FR 22715). We again reaffirm it here. To the extent feasible, tools used for working with ACM must be equipped with local exhaust ventilation. Some development work may be needed, but HEPA vacuum systems have been designed for many similar uses.

Other Basic Controls

The other basic controls in (g)(1), required for all operations under the standard are intended to reduce exposure caused by resuspension of asbestos fibers which have settled. The first is the requirement in (g)(1)(i) to use vacuum cleaners equipped with HEPA filters or other methods to collect debris and visible dust containing ACM or PACM before the material dries, which prevents the resuspension of fibers. This requirement complements the prohibition in (g)(2)(iii), which prohibits dry clean-up, including sweeping and shoveling, of dust and debris containing ACM or PACM. Although "wet" sweeping is not prohibited, it is not preferred, and may not be used to "collect" visible dust and debris. Nor may dry ACM or PACM-containing dust or debris be collected by means other than vacuuming with a HEPA filtered vacuum.

There was substantial record support for these requirements. As noted above these procedures apply to all asbestos operations. In removal operations, the requirement to use wet methods in the removal [(g)(1)(ii)] will help assure that resulting debris and dust can be collected before they dry out or are vacuumed up using vacuums equipped with HEPA filters (g)(1)(i). Even if operations are conducted within negative pressure enclosures, debris and dust should not remain uncollected for the entire work shift, because the resuspension of asbestos fibers from these sources creates additional new exposures for employees. If the work is performed within glove bags, leaks in the bags may create dust and debris. Fallen debris can be spread to parts of the building and thereby create widespread contamination. If the collection bags or devices required by other provisions fail or fall short, prompt collection of the dust and debris will limit the exposure to workers from such failure. If the negative pressure within the enclosure lapses, prompt collection of dust and debris will protect employees outside the enclosure from resuspended fibers. For these reasons, OSHA believes that careful treatment of asbestos waste and visible dust must be followed in all construction and shipyard industry operations which expose employees to asbestos.

OSHA notes that for demolition and renovation work which is covered under NESHAP (40 CFR 61 Subpart M), all ACM must be kept wet until sealed in a leak-tight container which includes an appropriate label. OSHA is extending this requirement to all jobs under the standard, and now requires that all asbestos-contaminated waste be promptly disposed of in leak tight containers [(g)(1)(iii)].

Requirements for Operations Which May Exceed the PELs

Paragraph (g)(2) applies to situations where it is expected that exposures may exceed the PEL, and thus additional controls are required to keep exposures at or below the PEL. Paragraph (g)(2) requires that local exhaust ventilation equipped with HEPA filter dust collection systems be installed for fixed processes involving asbestos handling and for power tools used in installing, or otherwise handling asbestos containing materials. In addition, enclosure or isolation of the asbestos releasing process must take place. These controls were listed as optional in the 1986 standard. They are now required, because of their proven ability to reduce dust levels in virtually all occupational environments. These controls, in particular, apply to construction activities involving the installation of new asbestos-containing construction materials, and in some cases the removal of previously installed material.

R.J. Pigg, President of the Asbestos Information Assn. of North America, testified that "the tools that we use, (for cutting asbestos-cement pipe as recommended work practices) are those that can be fitted with vacuum attachments. We have studies that relate to those recommended work practices that * * * support, when they're being followed, that you're well below the PEL" (Tr. 558-9).

In addition, paragraph (g)(2) requires that where the exposures are expected to be above the PEL, ventilation to move contaminated air away from exposed employees in the regulated areas toward a HEPA filtration or collection device is required. This requirement is adapted from the current standard which lists "general ventilation systems" as one of the control methods to be used to achieve the PEL. However, OSHA believes that the term "air sweeping away from exposed employees toward a HEPA filtered exhaust device" is more appropriate and effective. Further, it removes the interpretative possibility that using a general building ventilation system to vent asbestos-contaminated air, would be acceptable under the standard. A similar requirement is also aimed at Class I jobs which cannot produce a negative initial exposure assessment [see (g)(4)(F)].

Prohibitions

Paragraph (g)(3) sets out four prohibitions for all work under the standard. One prohibition, relating to high-speed abrasive disc saws, is made more specific; one, prohibiting dry sweeping and dry clean-up of ACM and PACM is added; and, one prohibiting employee rotation is expanded to apply to all attempts to reduce exposure, not, as in the 1986 standard, to reach the PEL. OSHA finds these changes will help reduce employee exposures and are consistent with the revisions to the standards.

Controls for Asbestos Jobs According to Their Classification

The next set of requirements in the "Methods of Compliance" beginning at paragraph-(g)(4), are keyed to the four classes of construction activities, Class I through IV, relating to previously installed ACM and PACM, defined in paragraph (b). The scheme is risk-based with Class I as the most hazardous, and Class IV the least so.

Class I asbestos work consists of the "removal" of asbestos-containing TSI and surfacing material and of PACM, including demolition operations involving these materials. Class II work consists of the "removal" of all other asbestos-containing materials, including resilient flooring presumed to contain asbestos. Class III work consists of the "disturbance" of all previously installed asbestos-containing building materials and PACM. Class IV work consists of housekeeping and custodial work in contact with previously installed ACM and PACM, and the clean-up of debris on construction sites.

All asbestos work under the construction and shipbuilding standards is not in the "class system." The installation of new asbestos-containing products does not carry a class designation, and thus the class-specific requirements do not apply to that activity. Work covered by the general industry standard is not included in the "class system" as well.

OSHA also notes that the differences in controls required among classes is not great. Further, the Agency believes that the risk overlap between adjoining classes is neither frequent nor large, and that the standard allows the employer flexibility in most such cases. The regulation requires job-by-job evaluation of regulated projects, and gives the competent person some leeway in easing some requirements when it appears that the project can be done especially safely.

The following examples illustrate how operations involving potential asbestos disturbance are to be classified. If an insulated pipe is leaking, and less than one standard glove bag's worth of TSI is "disturbed" (see definition in paragraph B) in order to repair the leak, it is a Category III job. If the TSI is stripped from a section of piping to inspect all the piping in an area for leaks, it is a Class I job. If the section of piping required to be stripped is less than 25 feet, it is still a Class I job, but critical barriers may not be required if the initial exposure assessment is "negative" [see (g)(4)(i)(B)]. If it is not clear which category the work belongs, the employer should assume the higher, more restrictive, category applies, and should comply with the listed work practices and controls for that category. OSHA believes that most asbestos work will fit easily into the categories which are defined.

OSHA found that the term "small-scale, short-duration," insufficient to distinguish lower risk asbestos operations which allow exemptions from generally required controls.

A historical perspective is useful to clarify this issue. In 1986, OSHA required that all removal, renovation, and demolition operations, except for "small-scale, short duration" operations, be conducted within negative pressure enclosures [29 CFR 1926.58(e)(6)(1986)]. The scope of both the requirement and the exemption was unclear. The requirement did not explicitly apply to "maintenance or repair" operations, though most of the examples given were in that category. The examples cited in the exemption included pipe repair, valve replacement, installing electrical conduits, installing or removing drywall, roofing, and other general building maintenance operations. In addition, OSHA maintained that it was not possible to specify with precision the exact size of a "small-scale" maintenance job or to pinpoint the time involved in a "short-duration" task.

The Court of Appeals stated that OSHA had not drawn the parameters of the exemption with enough specificity and that "the exception as now worded seems to erase the rule." As noted above the Court remanded the issue to OSHA to "clarify the exemption for "small scale, short duration operations" from the negative-pressure enclosure requirements. Further the Court suggested that OSHA limit the exemption to "work operations where it is impractical to construct an enclosure because of the configuration of the work environment," stated by OSHA in the preamble to the 1986 rule, as the intended scope of the exemption (51 FR at 22,711,2).

However, the consequences of qualifying for the exemption were less clear when the regulatory text was consulted. Section (e)(6) of the 1986 standard allowed "small-scale, short-duration operations" to be exempt from the negative pressure enclosure requirement for removal, demolition, and renovations operations. However, some contractors successfully argued in enforcement actions, that a NPE was a particularized kind of a "regulated area" which the overriding general provision required only in "work areas where airborne concentrations of asbestos exceed or can reasonably be expected to exceed the TWA and/or excursion limit" (Section (e)(1)). To impart certainty to the requirement OSHA issued a compliance directive which triggered the requirement at the PEL, and attempted to clarify the kind of operations which would qualify for the exemption, in a job where exceedances of the PEL were expected.

In its July 20, 1990 proposal, OSHA would have required NPEs based on the type of work to be done; and sought to clarify the definition of small-scale, short duration operations by proposing specific cutoffs for "small" and "short." In addition, general criteria were proposed which were intended to amplify the exemptive criteria: operations must be "non-repetitive, affect small surfaces or volumes of material containing asbestos * * * not expected to expose bystanders to significant amounts of asbestos * * * completed within one work day." Cutoffs for specific operations were: repair or removal of asbestos on pipes: 21 linear feet; repair or removal of asbestos panel; 9 square feet: pipe valves containing asbestos gaskets or electrical work that disturbs asbestos: one worker, four hours, removal of drywall: one workday, endcapping of pipes and tile removal: four hours, and installation of conduits: eight-hour work shift.

Many participants agreed that using only the duration, and size of a job did not adequately characterize risk. Some argued that all asbestos jobs were risky, indeed there should be little regulatory distinction made. For example, NIOSH spokesperson, Richard Lemen, expressed the view that "even with short duration, small-term jobs we still feel that there is a risk to the worker, not only from the one time exposures, but from the potential of that worker doing multiple jobs over periods of time * * * which increase the exposure each time and the lung burden of asbestos to each of those exposures * * * we still feel that * * * [these jobs] should be treated as protectively as the other type of jobs." (Tr. 244), [See to the same effect the testimony of Mr. Cook, an abatement contractor who testified for the BCTD and Lynn McDonald, representing the Sheet-Metal Workers Union, (Tr. 829ff)].

The proposed definition of small-scale, short duration operations included specification of the number of square and linear feet of asbestos-containing material. There were numerous objections raised to the proposed values.

Several participants suggested that the NESHAP cutoff of 260 square or 160 linear feet, used by EPA for notification, be used as the cutoff for small-scale work (Ex. 7-9, 7-21, 7-39, 7-52, 7-113, 103, 1-53, 1-55). Others such as Edward Palagyi, a Florida State Asbestos Coordinator, felt that this cutoff was too high for OSHA to use in its definition (Ex. 7-6).

Several alternate amounts of material were suggested. Christopher Corrado of the Long Island Lighting Company (Ex. 7-29), James Foley of the New York Power Authority (Ex. 7-31) and Robert Brothers of Eastman Kodak (Ex. 7-81) recommended that OSHA adopt the amounts used by New York in its small-scale definition -- 25 linear and 10 square feet. William Dundulis of the Rhode Island Department of Health felt that to avoid confusion, OSHA should adopt the same cutoff that EPA used in its Worker Protection Rule -- 3 linear and 3 square feet (7-124). Others suggested that the amount of material be defined by the amount of asbestos-containing waste generated by the activity. For example, Preston Quirk of Gobbell Hays suggested cutoff maximum of 55 gallon drum or 1 cubic yard of ACM waste material (Ex. 7-34), while OSHA witness David Kirby suggested 3 glove bags worth of waste material or 10 linear feet as the cutoff of a small-scale job (Ex. 7-111). BCTD suggested "the lesser of (a) a yield of no more than 1-1/3 cubic feet (10 gallons) of asbestos-containing waste material, or (b) a maximum length of 2 feet or a maximum area of no more than 8 square feet of material containing asbestos." Noting that the amount of material covering a pipe varies with its diameter, (and the thickness of the material) BCTD calculated that removal of 1 inch of insulation from common pipe dimensions can vary from 1.37 to 5.04 cubic feet of waste. (Ex 143 at 131).

Although OSHA believes that the amount of waste material generated by a job may be a valid index of its exposure potential, the Agency agrees with participants who pointed out the difficulties of estimating the amount of waste material in advance of the job. [e.g., testimony of Chip D'Angelo, an asbestos consultant, (Tr. 3086), Paul Fiduccia, representing a number of real estate and building owner interests, (Tr. 791); Paul Heffernan of Kaselaan and D'Angelo Associates, (Ex. 7-36)].

Various other quantitative limits were suggested which were tied to specific materials; (e.g. transite panels, 32 square feet (Ex. 7-94), 48 square feet (7-96). Mr. Churchill, representing the California Association of Asbestos Professionals, suggested 9 square and 9 linear feet as cutoffs for small-scale jobs (Ex. 7-95 and Tr. 3468).

Charles Kelly of Edison Electric Institute asked whether complete removal of a pipe which might exceed 21 feet in length, but which involved removal of less than 2 feet of insulation at either end to enable cutting the pipe length for removal would be considered a small-scale job (Ex. 156).

Many additional commentators and hearing participants discussed these issues during this rulemaking proceeding. Some commented that the duration cutoffs were not realistic or protective. Other participants asked for clarification on whether duration of the job included preparation and cleanup. Also, Captain John Collins of the US Navy felt that employers would abuse the exemption by assigning many employees to a job in order to complete it in a short time period (Ex. 7-52), and suggested that instead of specifying the number of persons and the number of hours, OSHA should set the limit in terms of man-hours [see also Churchill at Tr. 3468, ORC at Tr. 3181, Kynock of AIR Coalition (Tr. 3539)].

Daniel Bart of GTE Service Corporation expressed concern that by having a time limitation for small-scale, short duration operations in the definition, the installation of telephone cables in buildings might no longer be considered short duration (Ex. 7-87). Dr. Michael Crane of Consolidated Edison, New York objected to the requirement that an operation be non-repetitive in order to qualify as small-scale, short duration (Ex. 7-76). He said, "(t)here are jobs * * * not part of an overall asbestos removal but are performed many times in the course of day during routine maintenance that must be done in generation stations and other utility facilities" [see also the suggestion of Paul Heffernan of Kaselaan&D'Angelo to adopt the concept of "functional space" as designated under AHERA, and defining a non-repetitive operation as occurring once within such a functional space (Ex. 7-36)]. Some also asked if OSHA intended preparation time and clean-up time be included in the duration limits for SSSD (Ex. 7-108).

Several participants noted that most asbestos work would not be assigned to a single worker, and SSSD should include only jobs completed by 2 employees in one work shift (Ex. 7-31): Preston Quirk of Gobbell Hays Partners, Inc. suggested that a maximum of 3 workers be allowed (Ex. 7-34). Organization Resources Counselors, Inc. (ORC) maintained that the specification of the number of workers was not necessary, as long as the employer had a comprehensive safety and health plan. (Ex. 7-99).

The views on these defining variables has influenced the Agency's decision to broaden and realign its job classification system based on relative risk. Based on this record and the agency's experience in enforcing the 1986 standard's provisions on small-scale, short duration work, OSHA is dropping the term "small-scale, short term" work from the regulatory text. The agency finds that the term "small-scale, short term" is too limiting, has been shown to be confusing, and cannot be defined with sufficient precision to serve the purpose of distinguishing high risk asbestos-disturbing activity from activity of reduced risk.

The term is limiting because it focuses on a fraction of the circumstances and criteria which define lower risk work with asbestos- containing material. OSHA has found that thermal system insulation (TSI) and surfacing material are the asbestos-containing building materials likely to produce significant employee exposure. On the other hand, removing asbestos-containing products like transite panels, likely will not result in significant exposure, even if conducted for more than one day, under minimum controls. As much as the scope and duration of the job, the materials themselves, their condition and the work-practices used define hazard potential.

OSHA's organization of asbestos jobs into categories is based on the more objective criteria, such as the type of material to be disturbed and the type of activity. Factors which are more subjective, such as condition, and crew experience are part of the required pre-job assessment by a "competent person." Not concentrating on the amount of asbestos material or the time the job takes, avoids serious objections raised by rulemaking participants to the time- or volume-based definition in the proposal. For example, a frequent complaint was that the duration of the operation should not be specified in the definition of small-scale activities because this might create incentives to perform the work more hurriedly and in a more hazardous manner when the worker must meet defined time schedules (Ex. 7-18, 7-35, 7-37, 7-43, 7-50, 7-52, 7-54, 7-63, 7-74, 7-76, 7-81, 7-87, 7-89, 7-95, 7-99, 7-106, 7-112, 7-124, 7-128, 7-135, 7-139, 7-146, 7-151, 143, Tr. 417). (In a few regulatory provisions, however, OSHA still relies on the amount of material to be removed to indicate risk, and thus, the protections required. These are the exemption from critical barriers from low-exposure Class I jobs [see paragraph (g)(4) and in defining "disturbance"]).

This classification system is OSHA's response to the Court's remand issue of how to clarify the term "small-scale, short duration." (see also preceding discussion of classes of asbestos work under "Definitions.")

Class I Work

Class I work, i.e., the "removal" of TSI or surfacing ACM or PACM, must be performed using procedures in paragraph (g)(4) and using a control method which is listed in paragraph (g)(5) of the standard. If another control method is used, or if a listed control method is "modified," the standard in paragraph (g)(6) requires that a certified industrial hygienist (CIH), or licensed professional engineer who is a "project designer," certify the control method using the criteria set out in the regulatory text. The requirements of (g)(4) are: for Class I jobs, preparation must be supervised by a competent person, dropcloths must be used and HVAC systems must be isolated. The area must be set up using "critical barriers' either as part of a negative pressure enclosure system, or as a supplemental barrier to another listed system which isolates the asbestos disturbance in a different way. Other barriers or isolation methods may be used to prevent asbestos migration. The effectiveness of such methods must be proven by visual inspection and clearance or perimeter monitoring (see e.g., Ex. 9-34 cc). As noted below, OSHA believes that the size of the removal job alone does not predict the risk to workers. However, if a job is smaller, the chances are reduced that isolation barriers provided by glove bags or boxes will fail.

OSHA was reluctant to limit glove bag removals without critical barriers only to maintenance projects, where as NIOSH noted, it is more likely that crews will be untrained (Ex. 125). Rather, OSHA has followed the lead of some states, which allow removals involving less than 25 linear feet of TSI, and 10 square feet of other material to be handled without critical barriers, unless the glove bags or enclosure loses its integrity (see e.g., 12 NYCRR 56) or where a negative exposure assessment has not been produced. Such projects are class I removals, and workers required to perform them must be trained in an EPA-accredited training course or equivalent; OSHA believes that the work force performing these relatively minor removals is the same work force performing major removals, thus the jobs will be well-conducted and critical barriers will be unnecessary.

In addition, where the employer cannot demonstrate that a Class I job is likely not to overexpose employees, the employer must ventilate the regulated area to move contaminated air away from employee breathing zones.

Paragraph (g)(5) sets out five listed control methods which OSHA has evaluated during this rulemaking. The Agency finds that using these methods pursuant to the limitations and specifications in the paragraph is likely to effectively control employee exposures when performing Class I work. The first control system listed for Class I work is the Negative Pressure Enclosure System (or NPE). The extent to which OSHA should require these systems for major asbestos work was a remanded issue. As discussed in detail below, OSHA has found that NPEs, when constructed and used according to the criteria in this standard, can be effective in protecting employees within and outside the enclosure.

Other listed systems also may be used for Class I work under stated limitations. Paragraph (g)(5) sets out these limitations. These systems are: glove bag systems, negative-pressure glove bag systems, negative pressure glove box systems, the water spray process system, and a mini- enclosure system. OSHA emphasizes the use of the term "system." Each method consists of tangible materials and devices; and of procedures and practices. All the listed elements must be complied with before OSHA's finding of effectiveness are relevant. Other, unspecified control methods, "alternative control methods," may be used if additional notification is given OSHA, and if a specially trained "project designer" or a certified industrial hygienist certifies that the controls will be protective.

Participants in this rulemaking requested that OSHA's revisions allow alternative systems. OSHA agrees that asbestos removal technology is evolving. If another control method is used, or if a listed control method is "modified," the standard requires that a certified industrial hygienist or licensed professional engineer who is also qualified as a project designer certify the control method using the criteria set out in the regulatory text. Additional discussion of these issues is found later in this document.

Specific Issues Relating to Methods of Compliance

1. A major issue in this proceeding is when NPEs should be required. In the 1990 proposal OSHA would have required the erection of negative pressure enclosures for all asbestos removal jobs, except for "small scale short duration work." This proposal responded to the Court's order for OSHA to clarify the conditions under which negative pressure enclosures were required in the 1986 standard (see discussion on Issue #3).

The major rationale in the 1986 standard for requiring negative pressure enclosures was to ensure that contamination from large-scale asbestos projects did not spread beyond the work area. OSHA there stated that "general contamination of the workplace has resulted from failure to confine asbestos using strict regulated area procedures, and asbestos-related diseases have been found in workers of a different trade exposed to asbestos contamination from the activities of asbestos workers." (55 FR at 29716). The effectiveness of NPEs in protecting employees working within the enclosure was not the explicit basis for their adoption in the 1986 rule.

In the 1990 proposal, OSHA primarily based the requirement for universal NPEs for major asbestos work on limited data relating to contamination of workspaces adjacent to asbestos work, and reports of historic disease experienced by employers in trades other than asbestos work who worked alongside asbestos workers. OSHA stated however, that the Agency "has not been able to estimate the risk to bystander employees * * *" and asked for comment and data on their exposure (55 FR 29716). OSHA also asked for information about alternatives to work in full containment, such as glove bag and box systems and "new technologies" (55 FR 29717). Although OSHA proposed more tightly drawn exemptions to the required use of negative pressure enclosures, the Agency also raised the possibility that data to be submitted about alternative control systems might result in a limitation, rather than an expansion of the walk-in enclosure requirements (55 FR 29720).

Further the 1990 proposal specifically focused on whether work within walk-in enclosures was the optimum method to protect asbestos workers. It is widely accepted that employees who disturb asbestos, and who contact deteriorated asbestos during their work are most at risk (see e.g., Ex. 1-344, p. 1-12). In its earlier response to the Court's remand, OSHA noted that the "record of the 1986 standard contains no data concerning whether employees working within the negative pressure enclosures also benefit from reduced exposure, whether working inside enclosures may introduce other potential work hazards such as heat stress. Further rulemaking is necessary to develop this information." (54 FR 52026, Dec. 20, 1989). In the proposal, OSHA reiterated this statement and again raised this issue (55 FR 29715).

The rulemaking record reflected this two-part inquiry. Data and comment were submitted concerning the effectiveness of NPEs in protecting employees within the enclosure, and their effectiveness in protecting "bystander" employees and adjacent areas from asbestos contamination. The record presents a mixed case on both issues. First, very limited data were submitted showing that employees working within the enclosures experienced reduced asbestos levels because of the enclosures themselves, or the ventilation provided by negative air machines, in spite of claims that the enclosures and ventilation produce such results. In fact claims were made that in comparing work within enclosures to work without enclosures, "enclosures consistently came out higher in terms of what the person inside the enclosure is exposed to" (Exxon, Tr. 2678). However, the record contains some data which show that properly designed and installed NPEs may limit the spread of asbestos contamination to adjacent areas and employees. However, the record also demonstrates that other systems, properly installed and performed by trained employees will also limit the spread of asbestos contamination. These are discussed in depth below.

Based on this record and on the Agency's experience and expertise, OSHA has concluded that although negative pressure enclosure systems are effective in many circumstances in protecting workers both within and outside the enclosure, other systems are equally effective in designated circumstances. Additionally, the demonstration in this rulemaking that other systems can be effective, supports regulatory provisions which do not stifle continued development and refinement of control strategies for asbestos work.

2. Effectiveness of NPEs in Protecting Employees Working Within the Enclosure

As noted above, little data were submitted showing that employees working within the enclosure have reduced exposures because of the enclosure itself, or other components of the NPE system. Although much data was alluded to during the hearing, e.g., "* * * 10 years of real, real projects with rooms full of data, * * * we have some nice summaries that I can give you * * *."(Tr. 3133). However, none of these data was submitted to the record. Also, NIOSH testified during the rulemaking hearing, "we are not aware of any studies evaluating their (negative pressure enclosures) effectiveness or delineating important parameters such as minimum pressure differential, minimum air flow, or maximum volumes feasible for various barrier materials." (Tr. 228). BCTD noted a study in which "two MIT researchers estimated "that total exposures using the HEPA negative pressure system might be about four-fold less than they would be without the system" (Ex. 143 at 90). OSHA notes that this estimate was derived from "assumptions" of the study team, and was unsupported by exposure data. Further, the baseline exposure model was based on a much earlier study of activities cleaning up contamination in a building. During this rulemaking hearing, the author of that study described it as "extremely unique, * * * not representative of buildings in the United States" (Tr. 2157). OSHA therefore regards the MIT exposure reduction estimate as unsupported and too speculative to serve as a basis for regulatory decision making.

Exposure data submitted to this rulemaking record which reflected personal samples within negative pressure enclosures do not support the view that working within such enclosures by itself will ensure reduced employee exposure. In fact, data were submitted which showed that employees working within negative pressure enclosures under some circumstances were exposed to excessive levels of asbestos (see below). OSHA recognizes that a showing of elevated levels from any one project or series of projects does not indict the control method as the cause of such elevations. However, numerous submissions from various sources which show elevated exposure levels with no indication of improper system installation indicates that in operation, the use of negative pressure enclosure systems does not assure effective exposure reduction to the employees performing the work.

Thus, Union Carbide submitted 1,000 exposure measurements "generally obtained from jobs where insulation was removed from piping of 1" -14" diameter and from other miscellaneous jobs removing asbestos from vessels" (Ex. 7-108). More than one half of the samples were over the proposed PEL of 0.1 f/cc, and most of those were over the previous PEL of 0.2 f/cc. Additional data showing high exposures within negative pressure enclosures compared to relatively low exposure levels for glove bag use were submitted by Arco Products, Inc. (Ex. 7-139) and Grayling (7-144). The Arco submission contained monitoring results from 9 personal samples taken within the enclosure. These ranged from 0.01 to 0.44 f/cc with a mean on 0.28 f/cc. Lower exposure levels for work within NPEs was shown by data submitted by the Asbestos Abatement Council, presenting data incorporating air monitoring results for over 200 projects, collected from four different contractors over an eight year time period. These data showed area samples ranging from 0.12 to 0.15 f/cc, while personal samples ranged from 0.03 to 0.07 f/cc (Ex. 1-142).

Various reasons were advanced for the presence of elevated exposure levels within negative pressure enclosures. Thus Dr. Sawyer testified "I have seen configurations that not only don't work maintaining the enclosure integrity, but they actually can increase fiber burdens in the contamination area * * * (t)his involves * * * a HEPA filter by itself without a drive mechanism, without a fan to force air through it" (Tr. 2176). "I can anecdotally tell you what I've seen out there, but a lot of the systems just don't work, and some of them can actually increase the hazard to workers" (Id at 2177-78).

In view of the disparity in the submitted data, OSHA concludes that negative pressure enclosure systems, like other control systems which depend on proper installation, design and supervision for effectiveness, can vary in protection they afford to employees working within. Unlike engineering systems permanently installed which are capitalized by the facility owner, negative pressure systems are installed for the duration of the job, and economic pressures are exerted to hold down the time and cost of the installation.

Thus, the support for the use of NPEs to reduce employee exposure is mixed. OSHA is also concerned that other health and safety hazards may result from work in negative pressure enclosure systems. For example, problems with toxic adhesives were noted in the record. Levels of methylene chloride, used to seal poly sheeting to underlying surfaces to contain work areas have been measured at over the PEL for that substance (Ex. 1-24). Some of the polyethylene used for sheeting may be combustible (Ex. 7-18). Certain industries reported particular hazards of NPEs. For example, a representative of Arco Products Co. commented that in the gasoline industry hazards included: build-up of gases inside the enclosure, heat stress, fire hazards, lack of good ventilation, difficulty in working with mobile equipment, difficulties in communicating and exiting during emergencies (Ex. 7-139).

Various solutions to these problem were suggested. Thus, it was suggested that less toxic adhesives be substituted for methylene chloride; that poly sheets can be attached without adhesives (BCTD, Ex. 143); that heat stress be eliminated by increasing the number of air changes per hour within the enclosure; that a transparent window be installed in each enclosure to facilitate communication (Ex. 7-6); and other such adaptations. Certain of these suggestions were criticized as ineffective. For example, Union Carbide stated in its post-hearing submission, "(w)e have observed that even when 8 to 12 air changes per hour are provided to the enclosure, on certain days the inside of the enclosure temperature has risen as high as 140 degrees F. The heat stress situation is further exacerbated by the body coveralls worn by the workers" (Ex. 113 p. 6).

OSHA believes that some of these potential problems attributable to negative pressure enclosures may be averted. However, the record also indicates that the use of this control technique shares with other asbestos control methods, a primary reliance upon the skill and training of designers and workers to assure its effectiveness. In addition, under some circumstances even the proper use of negative pressure enclosures can introduce additional hazards into the workplace.

One feature of some negative pressure enclosure systems, negative air ventilation, was singled out by some participants as the primary means of reducing exposures to employees working within them. OSHA notes however, that the requirement for NPEs as adopted in the 1986 rule, did not contain any criteria for such ventilation, and that the rationale for requiring NPEs did not rest on the capability of ventilation to reduce employee exposure. Therefore, OSHA regards the recommendation for requiring special ventilation as a new claim, to be supported by evidence and testimony submitted to this record.

One of the main characteristics of the negative pressure enclosure system is that the air pressure inside the enclosure is less than outside the enclosure. This pressure difference is created by a fan exhausting air, through a filter, from inside the enclosure to outside the enclosure. Under negative pressure, any leaks in the walls of the enclosure will result in clean air coming into the enclosure, rather than contaminated air leaking to the outside. The system is primarily designed to keep asbestos from contaminating the building. As stated earlier, this approach does not appear to improve working conditions inside the enclosure. Negative air ventilation draws clean air from outside the enclosure at sufficient quantities and at strategic locations, so as to provide clean air in the worker's breathing zone. Support for negative air ventilation was submitted by numerous participants. For example, Mr. D'Angelo testified that "negative air ventilation is the single most effective engineering control reducing worker exposure as well as reducing the risk to adjacent bystanders or other operations." Further, he recommended a minimum of 8 and up to 20 air changes per hour to assure appropriate ventilation is maintained (Tr. 3078, 3087). This process, "which has expanded on the negative pressure enclosure, (is) called air flush methodology" (Tr. 3085).

Other participants also supported the use of "air flushing" techniques, or directed make-up air. Chip D'Angelo, an asbestos abatement consultant described the principle as moving airborne fibers out of the work area with air velocity, thereby "flushing" the area by bringing in air from sources outside the enclosure additional to that brought through the decontamination chamber. He further described moving the air away from the worker and toward the negative air filtration machines and directing the moving air to "dead spots" in the enclosure by use of baffles and flexiducts (Tr. 3035) (see BCTD, Ex. 143 p. 90, and citations therein). Mr. Cook, an asbestos abatement contractor, appearing for the BCTD, testified that "it's a fairly easy technology to implement, depending on the situation."(Tr. 805). Mr. Medaglia, president of an engineering firm suggested adding to the definition of a negative pressure enclosure, the phrase "* * * all areas within the enclosure are swept by the flowing air towards the exhaust fans * * *" (Tr. 3052). Other support was provided by New Jersey White Lung Association (Tr. 601-2), NIOSH (Tr. 228 and 257), R. Sawyer (Tr. 2161), D. Kirby (Tr. 170), Global Consumer Services (Tr. 2341) and J. Cook of QSI International (Tr. 804.) However, some engineers who testified did not utilize the technique;

Exxon noted in its testimony that "you can't, quite honestly, get enough volume of air velocity to convince yourself you are going to get good equal mixing within an entire enclosure" (Tr. 2680); and NIOSH noted in its submitted testimony, that "we are not aware of any studies evaluating their effectiveness (NPE's) or delineating important parameters such as * * * minimum air flow" (Ex. 9). NIOSH recommended that OSHA incorporate into the rule for negative-pressure enclosures, design requirements for air-flow patterns within the enclosure to move airborne particles away from the worker" (Ibid).

Although "air flushing" is the ventilation approach most recommended for use within negative pressure systems, actual data showing its success is limited. In recognition of the support from engineers who have utilized these systems, OSHA is requiring a performance based version of "air flushing" as a component of the negative pressure enclosure system. OSHA is also requiring ventilation which "directs the air away from exposed employees" when other controls are used for Class I work where no there is insufficient data to support a "negative exposure assessment."

Participants also argued that the use of negative pressure systems under stated circumstances was unnecessary and would not contribute to employee protection against asbestos exposure. Working outdoors was one such circumstance. Amoco submitted data in which 95% amosite was removed from an outdoor pipe run without negative pressure enclosure in which most samples indicated very low fiber levels (Ex. 7-39). However, the following work practices were also used: restricted access, immediate and double bagging of debris or use of airtight chutes, barricaded area, use of HEPA equipped vacuums, respirator, decontamination procedures, and training and supervision of the operation by a competent person.

OSHA believes that outdoor Class I work may be safely done without enclosures. Therefore, paragraph (g) allows all outdoor Class I work to be conducted using other control methods, such as a glove bag system, so long as the specifications and work practices for such systems are followed. In addition, decontamination procedures for all Class I work, outdoors as well as indoors, including decontamination facilities and showers, must be made available for all Class I work, including that performed outdoors.

As discussed above, the negative pressure enclosure requirement in the 1986 standard lacked specificity. BCTD recommended that OSHA specify the number of air changes per hour required in the negative pressure enclosure (Ex. 143, p. 94). They reasoned that this would improve ventilation within the enclosure and reduce worker exposure. Union Carbide testified that they use 8 to 12 changes per hour (Tr. 2255) and Chip D'Angelo recommended 10 changes per hour (Ex. 99). New Jersey White Lung Association representative suggested 8 changes per hour (Tr. 482). BCTD and others also proposed that the negative pressure differential be increased from the recommended 0.02 column inches water in Appendix F (Ex. 143, p. 95) "because of fluctuations inside the enclosure."

In several published articles, Spicer and D'Angelo expressed their support for these recommendations and further suggested that pressure measurements be made at several points within the enclosure (Ex. 9-34 NN, Tr. 3126). The use of a manometer to measure the pressure differential between the enclosure and the area outside the enclosure was also supported by BCTD and D'Angelo and Spicer primarily because this device would provide immediate notice if there were a loss of pressure and therefore increased potential for fiber escape (Ex. 143, p. 96 and Ex. 9-34 NN). He estimated the cost of a manometer at $20.00 (Tr. 3078).

BCTD submitted additional recommendations which it felt would improve negative pressure enclosure use:

 

  • -- Use additional air filtration machines in areas of especially high
    fiber concentrations, to serve as "scrubbers"
    -- Use at least one negative air filtration machine per room in
    multi-room enclosures
    -- Provide an independent power source and back-up HEPA unit for use in
    case of failure
    -- Smoke test the enclosure for leaks
    -- Pre-filter inlet air (Ex. 143, p. 97)


  •  

 

Most of these recommendations appear to be beneficial. Requiring smoke testing to detect leaks is adopted by the Agency as part of required set-up procedures when such enclosures are used. Others, such as requiring "additional air filtration machines * * * where exposures are especially high" appear to be sound engineering advice but would present enforcement problems, if included in the regulatory text (Ex. 143). Instead, as part of the mandatory criteria for NPEs, when used to control exposure in Class I jobs, the Agency is requiring "competent persons" to oversee the installation of such systems, and employees to be protected within such enclosures by ventilation systems which minimize their asbestos exposure. OSHA believes that its provisions on negative pressure systems will protect employees working within them.

Based on the above extensive analysis of the many studies and comments, OSHA has concluded that NPEs are not appropriate as a universal requirement. They usually protect bystanders well, but not always workers within the enclosures, and can sometimes create other problems. Consequently, OSHA is permitting alternatives to NPEs in appropriate circumstances and is upgrading requirements for NPEs when they are used.

Also, OSHA believes that various alternative requirements in this final revised standard triggered by Class I, II, and III work, some of which are components of negative pressure systems will protect adjacent or "bystander" employees under most situations. Thus, mandatory critical barriers for most Class I, some Class II and III work will bar passage of fugitive asbestos fibers; and, clarifying the responsibilities of the various employers on a multi-employer worksite, paragraph (d) will protect all work site employees from fugitive emissions.

3. What Other Control Systems Can be Allowed for Asbestos Work Which Involves High Risk Materials?

OSHA is allowing other control systems for Category I asbestos work, but only under stated conditions. Thus, the second asbestos control system permitted for use for Category I asbestos work is a glove bag system which meets the requirements of the standard, and is used only in the limited situations listed in paragraph (g), i.e. straight runs of piping and to remove intact TSI.

Other technologies recommended by the accredited project designer or competent person based on supporting data showing their effectiveness may also be used. Whenever a technology is used which is not referenced in the standards, the employer must notify OSHA before the asbestos job, and include in the notification the basis for the project designer's or certified industrial hygienist's decision that the new technology will be equally effective as other technologies referenced in the appendix. Daily personal and periphery area monitoring must be conducted for all such jobs, as well as clearance samples at the termination of the abatement job.

Glove Bag Systems

The decision to allow increased glove bag use is based on the considerable comment and evidence submitted during this proceeding concerning the safety and effectiveness of glove bag use. OSHA had proposed to permit only small-scale, short duration removals to be conducted using glove bags; however the Agency noted that it was considering whether alternatives, including glove bags, to negative pressure enclosures for renovation, removal and demolition operations should be allowed (55 FR at 29716).

In the 1986 standard, glove bag effectiveness was considered too uncertain to allow as a preferred control. Therefore OSHA relegated glove bag use to small-scale, short duration jobs, or jobs exempt from the negative pressure enclosure requirement because of the configuration of the work environment. However OSHA noted that glove bag use could generally be expected to reduce exposures to below 0.1 f/ cc (51 FR 22711).

In the preamble to its proposed amendments the Agency noted that available data indicated that glove bags in use may not always provide adequate protection. In large part, the Agency based this preliminary evaluation on the results of an evaluation performed by NIOSH in which improperly used glove bags resulted in excessive fiber counts.

As noted above, this final construction standard expands the conditions in which glove bag use is allowed. Now, glove bag use for removal of TSI and surfacing ACM is allowed without quantity limitation for intact TSI for straight runs of piping.

OSHA believes these decisions are well supported by this rulemaking record. Many participants urged OSHA to expand the conditions for permitting glove bag use. For example the Dow Chemical Company stated, "removal of asbestos containing material from pipes or pipelines can best be accomplished with the use of glove bags in all instances, not just when pipes are elevated. Needless to say, the employees carrying out the operation must be trained and adequately supervised to the glove bags properly." (Ex. 7-103). The American Paper Institute and the National Forest Products Association stated that "(w)e fully agree with the field personnel that there should be no linear footage limit for the removal of asbestos insulation on pipe when proper glove bag techniques are used" (Ex. 7-74 at 9). The National Insulation and Abatement Contractors Association commented "(a) skilled asbestos abatement mechanic can certainly remove in excess of 21 linear feet in properly used glove bags in as safe a manner as he or she can less than 21 feet. * * * (i)n addition, the implied restriction against glove bag use outside of small-scale, short-duration work ignores the advances made in glove bag practices and worker skills" (Ex 7-72 at 2).

Mr. Vest of the U.S. Air Force commented: "(t)he regulation should clearly allow for * * * operations that are not small-scale, short duration but are also not within the purview of the full requirements for a regulated area. We believe multiple glove bag operations would fall into this category; this in-between category should require training and additional procedures, but not necessarily "negative pressure enclosures." James Snyder, representing the American Paper Institute, maintained that there should be no linear limit as long as proper glove bag techniques were used (Ex. 7-74). Exhibits 7-9, 7-19, 7-21, 7-26, 7-32, 7-33, 7-50, 7-63, 7-72, 7-73, 7-74, 7-76, 7-95, 7-99, 7-102, 7-103, 7-106, 7-107, 7-120, 7-121, 7-125, 7-128, 7-130, 7-139, 7-144, and 7-146 also supported expanded glove bag use.

In addition, to these generalized statements of support for expanded use of glove bags, participants submitted data to show the effectiveness of glove bags in protecting workers. For example, the U.S. Air Force, introduced data (Ex. 3-9). The large majority of measurement were below 0.1 f/cc. Only 54 of the 370 measurements sets were over 0.1 f/cc, some of which were within the sampling and analytical error margin of 25%.

Dr. Vernon Rose of the University of Alabama at Birmingham submitted a paper entitled: "Analysis of PCM asbestos air monitoring results for a major abatement project" (Ex. 7-194), in which over 2000 sampling results were presented, taken over a five year period during which thermal system insulation was removed from a single building. This study provides very extensive data on closely observed work which the authors described as "* * * ideal conditions existed to support the proper abatement of ACM" (Ex. 7-194). However, they also noted that the environment was generally quite dusty and that since the results were PCM counts, they might overestimate the true exposure level. The results are summarized Table I.

Table I. -- Asbestos Fiber Levels During Various Removal Operations

[Ex. 7-194]
Sample description No. samples Mean (f/cc(3)) Confidence interval
Full enclosure-entrance 303 0.026 0.021-0.033
Full enclosure-background 333 0.022 0.019-0.025
Mini-enclosure-entrance 35 0.022 0.016-0.036
Mini-enclosure-background 38 0.023 0.013-0.058
At glove bag 430 0.037 0.034-0.041
Glove bag-background 386 0.028 0.025-0.031
Full enclosure-clearance 161 0.002 0.002-0.003
Mini-enclosure-clearance 94 0.006 0.005-0.008
Pre-work 39 0.013 0.010-0.018
Full enclosure-personal 116 0.233 0.177-0.327
Full enclosure-within 160 0.119 0.097-0.152

Except for those taken within the negative pressure enclosure, all sample means, including those taken at and away from glove bags are well below the new PEL of 0.1 f/cc.

In OSHA's view, the large amount of data contained in this study demonstrating that exposure levels at the glove bag consistently were well below the PEL of 0.1 f/cc supports the effectiveness of glove bags in protecting the asbestos worker.

Additional data were submitted by Grayling Industries and Control Resource Systems, Inc., glove bag manufacturers (Ex. 7-144). Personal breathing zone measurements representing varied removals are almost all below OSHA's proposed PEL of 0.1 f/cc. After the hearing, Grayling submitted letters from some of the contractors and organizations in charge of the projects for which data was submitted, which detailed the procedures followed by employees during the jobs where low exposure levels were recorded. (Ex. 111). These conditions correspond to the specifications and work practices which OSHA is requiring in this standard for glove bag use.

Virtually all of the participants who opposed expanded use of glove bags for removal jobs, cited the NIOSH study referred to above. (See e.g. Ex. 143 at 98-100). The study was conducted jointly by NIOSH and EPA in 1985, and its results were made public, as a Health Hazard Evaluation (Exs. 1-1, 1-2, 1-20). It has also formed the basis for NIOSH's institutional position on glove bags published as "An Evaluation Glove Bag Containment in Asbestos Removal" in October 1990. (submitted post-hearing as Ex. 125). Based on the data and analysis in that document, NIOSH's spokesperson, Richard Lemen testified at the rulemaking hearing:

NIOSH has found that airborne fibers are released in the work place when glove bags are used to remove asbestos pipe. Although the reasons for these releases were not determined, the study indicated that glove bags did not control asbestos exposures as anticipated. Thus, NIOSH strongly supports OSHA in requiring that negative-pressure enclosures be used in conjunction with glove bags. Furthermore, NIOSH recommends that OSHA require the use of respiratory protection when glove bags are used. At a minimum, NIOSH recommends that workers should be required to wear the most protective air-purifying respirators * * * (Tr. 229)

The study evaluated the removal of asbestos containing pipe lagging using glove bags from four public school buildings. The data were obtained during week-long surveys in each of the buildings. According to the abstract in the evaluation: "the same work crew removed asbestos-containing pipe lagging in all four schools. Personal exposures to airborne fibers were determined using the NIOSH method" (Ex. 125). NIOSH summarized the results: "* * * In three of the four facilities studied, workers were exposed to airborne asbestos concentrations above the OSHA PEL. Only in the last building where the removal took place, were exposure levels reduced to below the new OSHA PELs."

Interpretation of the results of this study varied. BCTD viewed the study as supporting its view that glove bags should not be permitted for other than small scale, short duration jobs because they do not provide reliable protection for bystanders. (Ex. 143, p. 98). HEI concluded, based on the NIOSH study, that "* * * glove bags should never be used as a stand alone abatement isolation procedure for long pipe runs" (HEI, Ex. 1-344, p. 5-48). Clearly these results call into question any expansion of permitted glove bag use. However, after paying close attention to the conditions, personnel and equipment utilized in the NIOSH study, and to the rest of the record, OSHA believes that glove bag systems, when properly deployed and supplemented by barriers, are capable of protecting both the abatement worker and bystander employee.

Details of the improper usage in the NIOSH study were pointed out by Grayling and CI and by the NIOSH investigators themselves; "the methods employed by workers * * * violated current state-of the art glove bag procedures * * * (t)he glove bags contained over four times the recommended material, they were opened up and slid down the pipe, * * * (t)hey were used as a receptacle rather than as a glove bag, * * * the envelope was slit to speed the removal process, * * * bags were being sealed while removal was taking place * * *" and other improper procedures (Ex. 130, Ex. 125). In addition, although NIOSH noted "[w]orker training and experience are important components in a reliable system of control measure, * * * (in this study) the work crew was not trained in the proper use of glove bags" (Ex. 125, p. 20).

Representatives of the glove bag industry also noted that since the study was undertaken in 1985-86, the equipment used by the workers, has been replaced by better designed and more protective equipment and materials. For example, one of the glove bags used in the study employed a zippered connection system, which "promote(s) the free flow of contaminated air from the glove bag during removal * * *," and the "one-size fits all" glove bag has been replaced by a "greater number of designs and configurations of glove bags * * * (for) T's, elbows, valves, verticals and extended runs" (Ex. 130, p. 3).

The study showed that by the time the removal activity reached the fourth (final) building, the work crew, having been "trained" by a variety of on-the-job methods, such as "trial and error," advice from the survey team, and watching a videotape, exposure levels were dramatically reduced. The pre-removal levels were not lower at the final facility, approximately the same amount of asbestos was removed as in the other operations and the authors stated that the lagging was in generally good condition throughout the study -- lending further credence to the hypothesis that the use of improved work practices led to generation of lower fiber levels. The report concluded with a list of recommendations for work practices for glove bag use.

OSHA believes that the NIOSH study should be viewed as a demonstration of poor work practices by untrained employees. The Agency notes that although the NIOSH study contains carefully presented and analyzed exposure data, the study design was compromised by the intervention of the investigators in instructing the workers. Further, since the workers were untrained, and for the most part did not use the glove bags correctly to attempt to isolate the disturbances, the study is of limited utility in identifying problems of glove bag systems when they are used correctly.

NIOSH speculated that ignorance of proper glove bag procedures was common for plant maintenance personnel, asbestos operations and maintenance personnel, and many asbestos removal contractors who use glove bags only occasionally" (Ex. 125, p. 53). If indeed this is so, it suggests that short of prohibiting glove-bag removals entirely, restricting permitted usage to, for example, maintenance work (small- scale, short-duration work) may result in limiting permitted glove bag work to where it is likely to be performed incorrectly. It also suggests that, the frequency of glove bag work, rather than the size of the removal project is more relevant to its effectiveness. Other participants echoed this caution, for example, David Kirby of Oak Ridge National Laboratory testified that glove bag usage should be conditioned on showing quarterly frequency of glove bag usage (Tr. 116-17).

OSHA concludes that when conscientiously used by well-trained, well-supervised personnel, glove bags can effectively reduce asbestos fiber release. The NIOSH study demonstrated clearly that the obverse is also true; when glove bags are used improperly by untrained or insufficiently trained workers, airborne fiber levels can become significantly elevated. Consequently, based on this extensive evidence and analysis, OSHA is permitting wider use of glove bag technology in the final standard, but is including additional requirements to improve the effectiveness of their use. The Agency notes that the new regulatory text prescribing the specifications and work practices for allowable glove bag removals would prohibit the kind of removal activity observed in the NIOSH study.

Based on its study, NIOSH recommended detailed work practices and specifications for glove bag use. OSHA has incorporated the major recommendations into the standard, either as part of the overall requirements for asbestos removal, or as required components of permitted glove bag systems. For example, NIOSH recommends that workers "spray frequently during the removal process so that newly exposed surfaces are wetted." OSHA requires that all work be performed using wet methods. "Wet methods" are defined as, applying sufficient water to ACM and PACM during the work operation so that fibers, if released, are prevented from becoming airborne. Other recommendations likewise are covered by more generic requirements.

For Class I work in which glove bags are used, OSHA is requiring that 2 persons perform the glove bag removal. BCTD recommended that 2 persons perform glove bag work stating that "* * * the operation can be hard-pressed to adjust the HEPA vacuum flow rates or water pressure in the sprayer while his/her hands are in the bag" (Ex. 143, p. 125). BCTD also felt that proper decontamination required a "buddy system" involving a second worker.

Exxon representative, Mr. Booher, testified that their practices is to have 2 persons per glove bag (Tr. 2673). Mr. Sledge of Naval Sea Systems Command testified that two personal normally perform glove bag operations in their facilities, usually using glove bags under negative pressure (Tr. 420). OSHA agrees and believes that proper use of glove bags in removing high-risk ACM (TSI and surfacing ACM) requires at least two persons. The Agency also notes that required training of employees must cover detailed glove bag procedures. Many of the detailed work practices recommended by NIOSH are advisory, i.e. use "sprayer of sufficient length," will be covered in training, and/or are encompassed by more general requirements.

Other Systems

Although glove bag systems were the alternative system most discussed during the rulemaking, participants submitted data on other systems which were claimed to effectively isolate asbestos dust during removal. The Agency has reviewed the data and comment on these submissions and has listed four additional systems as permitted for Class I work under stated circumstances in paragraph (g)(5). The Agency emphasizes that the listing of any system is not an endorsement by OSHA. The listing merely indicates that various combinations of engineering controls and work practices represented by these systems, when properly carried out, and when all other provisions of these standards, e.g., training, competent person supervision, exposure assessments and respirator use where required, are found by the Agency on this record to constitute effective means of controlling employee exposure to asbestos.

Two of the systems are modifications of glove bag systems. One, a negative pressure glove bag system, was presented as an alternative by several participants. One witness stated that "the nuclear ship repair industry has used pipe containment glove bags for years * * * all of this work has been required to be performed with constant negative pressure being maintained inside the glove bag during removal operations" (Tr. 3028). A panel testifying on behalf of Union Carbide described a negative-pressure glove bag technology which they have developed (Tr. 2192 and Ex. 7-108). M. Patel, an industrial hygienist at Union Carbide, described it in his written testimony:

The glove bag system is used as follows: The glove bag is connected to the glove/hose connector. All the tools needed to remove asbestos are placed in the inner pouch of the glove bag. The bag is installed on a pipe utilizing the zipper provided at the top. The shoulder is fastened on both ends of the glove bag with tourniquets. The rest of the system is connected. The insulation is wetted with amended water using the portable garden sprayer. The asbestos is cut and falls through the open sliding gate valve and collects in the waste bag. Vacuum in the bag and in the rest of the system is adjusted to prevent collapse of the bag. When the asbestos waste collected in the bag is almost full, the sliding gate valve is closed as the vacuum in the system is slowly controlled by adjusting the splitter valve, and the bag is carefully sealed and removed. A new bag is installed and the sliding gate valve opened. When all asbestos inside the glove bag is removed, the pipe and the wall of the glove bag above the middle zipper inside the bag are rinsed with amended water. The middle zipper is closed to isolate the upper compartment while vacuum is still being pulled.

The tourniquet on either end of the glove bag is loosened and the bag is moved to the next position. The middle portion of the bag is unzipped and the work is continued Ex. 9-43).

The panel members reported that the mean value of the exposure for the modified negative-pressure glove bag was 0.02 f/cc.

In a post-hearing submission, Union Carbide submitted a large number of additional measurements from various operations supporting the relative effectiveness of their negative-pressure glove bag method of asbestos control. These data showed both glove bags and negative pressure glove bag personal exposure levels were low, and well below those for negative pressure enclosures as measured by the company.

Table II. -- Asbestos Fiber Levels During Removal Operations

[Ex. 113]
Operation No. samples Sample type % > 0.1 F/CC
Glove bag 2,280 Area 2.3
Negative-pressure enclosure 1,220 Area 16.4
Glove bag 2,361 Personal 22.7
Negative-pressure enclosure 1,001 Personal 60.9
Negative-pressure glove bag 90 Area 1.1
Negative-pressure glove bag 80 Personal 10.0(1)
Footnote(1) mean of those >0.1 f/cc = 0.21 f/cc, the overall mean = 0.046 f/cc

Some of the exposure monitoring results showed personal samples above the new PEL of 0.1 f/cc. Union Carbide suggested, that employees performing Class I work using the modified negative pressure glove-bag, wear respiratory protection. OSHA is requiring that all employees who perform Class I work wear respirators.

Additional data on negative pressure glove bags showing effective exposure reductions was submitted by others, including NIOSH (Ex. 1-125, 1-126). "Opinion evidence" was that negative pressure glove bags, when properly used, offered an additional margin of safety over non-negative pressure glove bags (see e.g., testimony of David Kirby, Tr. 188).

Based on these data, OSHA is allowing negative pressure glove bags for Class I work, subject to similar limitations as "regular" glove bags.

Another method allowed for Class I work is the negative pressure glove box. This isolation device, is a rigid containment, unlike the glove bag, which is made of flexible material. Because it can be constructed of strong, impermeable material, common glove bag failures due to holes, leaks and collapse, would theoretically be avoided.

Mark Mazzara of SDS International Builders submitted several documents describing a negative pressure glove box, which his firm was marketing. The accompanying brochures described it as follows:

* * * system allows for the removal of ACM on pipes by creating a closed work area around the pipe section to be worked on. * * * consists of work box, together with a pressure barrier generated by the systems inherent Negative Pressure filtration system. The Work Box is a maneuverable element of sturdy metal construction that is positioned around the unit of pipe to be worked on * * * [it] is fitted with standard gloved apertures allowing for access into the closed system for the asbestos workers. At the base of the Work Box is an aperture feeding into a bagging outlet into which the liberated ACM is passed. This allows for easy bagging of the ACM and its subsequent disposal. * * * [it] is attached to a * * * negative pressure generator, that allows the creation of the pressure barrier that allows the creation of the closed system, preventing the escape of hazards materials into surrounding area (Ex. 7-98).

The submissions contained numerous sampling results indicating that low fiber levels were maintained during the use of this device. Accompanying these was a letter from the State of New Jersey in which the Division of Building and Construction (Frank J. Kuzniacki) stated that he felt that the device "provided a safe and cost effective alternative to standard glove bag removal."

The last method specifically listed for Class I use is designated the "water spray" process. In submissions to the docket and in testimony at the public hearing, representatives of Hydrous Dust Control Systems, Inc. described an alternate method of control for use in work on asbestos covered pipes which they called the Portam Process. This process relies on water spray to provide a barrier between the worker and the ACM. In written materials it was described as follows:

Engineered designed sprays are configured so as to create a liquid barrier on every plane. The spray is so designed as to throw a heavy droplet of liquid giving it both velocity and direction. On at least one of these planes * * * the heavy water droplets are forced into collision creating a very fine aerosol which is contained within liquid barriers. A water containment device is placed around the spray rails with an open access and double drain facility. A vacuum hose is connected to the drain facility creating a slight pressure differential (negative pressure), in the contained area. When water covers the drain area the pressure differential is maximized in the drain hose pulling the waste and water very rapidly to the remote interceptor. This movement creates a shock pulse which is quite visual and is reflected at the workhead. The sudden movement of air within the work zone helps to stimulated the fine aerosol droplets creating eddy current. These eddy currents promote a 360 deg. precipitation around the pipe (Ex. 1-171).

Data were presented showing that use of this system achieved consistently low exposure levels. However, the complexity of the system, and its uniqueness require, as the manufacturer recommends, additional training for effective use. Therefore OSHA is allowing this system to be used only by workers who are trained in a supplemental 40 hour training course in the specific use of this system, including at least 8 hours of which must be hands-on training. Although BCTD stated that this system possessed a high potential for exposure because it is not a sealed system, (Ex. 143, at 103), OSHA believes that the technology of the water spray system is sufficiently proven by the data submitted.

Other specific systems which do not easily fit the descriptions of the above systems were discussed during the rulemaking. Some, such as the "Lyons Trough" appear promising, however, the data submitted are too limited for OSHA to determine effectiveness in the rulemaking. Several TEM and PCM measurements were made during a "controlled demonstration" which lasted 31 minutes and during "field evaluation" of 29 minutes. The personal sample from the former was below the limit of detection by PCM, and the personal sample from the latter measured 0.002 f/cc by PCM (Ex. 135).

Other methods appeared too limited in application to be "generically" approved by OSHA, and/or appeared highly dependent on worker behavior to avoid failure. Such a system, devised by Tenneco, is a modified glove bag/mini-enclosure to facilitate safe removal of small amounts of asbestos fireproofing above ceiling tiles (Ex. 65 A-P). In its post-hearing brief, the BCTD objected to the use of the Tenneco device for two reasons. First, because it was held as close as possible to the ceiling and did not fit against it, they felt there was potential for fiber escape; and second, they questioned how effective it would be if one of the workers holding it up got tired and dropped it. (Ex. 143, p. 103). OSHA agrees; the device may be used therefore only as an alternative control method pursuant to the requirements for certification in paragraph (g)(6).

Mini-Enclosures

Mini-enclosures, the other control method allowed for Class I work is supported by a submission by BCTD which described a portable isolation enclosure developed by J. Streiter of Southern Insulation Inc. (Ex. 119, #5). OSHA notes, however, that mini-enclosures are manufactured by other companies and this rule does not limit use of the device to any particular manufacturer. In an accompanying trade paper article the portable enclosure is described as: "a cubicle with an extendable shroud that fits on top. A HEPA filtration system drew air down from the ceiling. Inside the enclosure was a suited man; opposite was a trapped door with a bag attached * * * the worker remove[d] the tile, clean[ed] off the grid and deposit[ed] everything in the bag after opening the trap door. Suction would pull the door shut. Within the enclosure was a shower attachment * * *" The submission also contained air sampling data obtained during use of this apparatus while removing ceiling tiles from a Virginia building. The results indicated that fiber levels averaged less than 0.01 f/cc. However, as pointed out by BCTD in its post-hearing brief there was failure to achieve clearance (0.01 f/cc under AHERA) in this building following use of the device which "necessitated evacuation of the work areas on several occasions." As explained elsewhere in this document, OSHA is not requiring AHERA clearance levels to be achieved for Class I work. If such requirements must be met, the employer should employ all applicable controls which in some cases may exceed those in these standards.

Class II Work

Class II asbestos work is defined as activities involving the removal of ACM or PACM which is not TSI or surfacing ACM. According to the definition, this includes, but is not limited to, the removal of asbestos-containing wallboard, floor tile and sheeting, gaskets, joint compounds, roofing felts, roofing and siding shingles, and construction mastics.

OSHA has found that the exposure potential from Class II work is generally lower than for Class I work, when removal is conducted under substantially similar conditions. Consequently, if the employer shows, that in any particular job, that well-trained and experienced workers, with an established "track record" of keeping exposures low will perform that removal, the required controls are less stringent than those required for Class I removals.

Removal of materials which are not TSI or surfacing ACM may be handled by complying with work practice and engineering control requirements for Class II in paragraph (g)(7), and the generic requirements for all asbestos work in (g)(1) of the standard. Additionally, methods allowed for Class I removals may be used for Class II work, unless the system cannot be adapted for Class II work, such as in the case of the water spray process system. Glove bags/boxes can be installed around some materials covered by the Class II designation, such as gaskets and ceiling tiles. It is OSHA's intent to allow Class I methods to be used for removing Class II materials when no modification in the apparatus is required, without special notice to OSHA.

As Class II work, removal of asbestos-containing material such as floor tiles and roofing will not be subject to quantity cut-offs for using certain control methods. This is similar to the proposal, which would have allowed these materials to be removed using mandated work practices, and exempted compliant jobs from negative pressure enclosure requirements. Under the final standard, other materials classified as "miscellaneous" by EPA such as transite panel and valves/gaskets may be removed without quantity limitation so long as Class II work practices are followed. Additionally, the standard allows all other materials (except TSI and surfacing ACM) to be removed using the generic work practices in paragraph (g)(1) which require wet methods, HEPA vacuuming and prompt waste disposal, and pursuant to additional controls in (g)(2) if the PEL may be exceeded.

Paragraphs (g)(7)(i) and (ii) establish "setting-up" requirements which apply to all removals of all Class II materials. These include the requirement that a competent person supervise the work and that where a negative exposure assessment cannot be produced or changed conditions during the job indicate elevated fiber levels, critical barriers or other isolation methods must be used or where the ACM is not removed in a substantially intact.

OSHA is also listing specific work practices for some kinds of Class II work which are common, such as removing flooring material or roofing material, as proposed. The generic list of work practices for all operations under this standard in paragraph (g)(1), covers most specific practices set out for each kind of removal. However, since both OSHA and participants believe that stating how each kind of material must be removed in specific terms will enhance compliance, paragraph (g)(7)(2) restates the relevant generic requirements in terms specific to each activity. For example, using wet methods for all asbestos work, unless the employer can show wet methods are infeasible, is now required, in the generic requirements, for all asbestos work [see (g)(1)]. However, wet methods encompass a range of work practices. For example, when removing material which is bound in a matrix, misting may be appropriate. Removing ACM or PACM which is not so bound, or where deterioration of the ACM has occurred, would require more aggressive wetting.

Thus, in the paragraph applying to flooring removal, the employer must mist the "snip point" used for cutting sheet flooring. For roofing removal, the blades of all powered tools must be continually misted during use. OSHA believes these more specific directions will help insure that work is done protectively.

OSHA proposed to require use of wet methods to remove sheet floor covering. RFCI guidelines state that floor tile is to be removed by prying up an edge but no mention of the use of water on the floor tile is made. The revised standards require the use of wet methods wherever feasible including operations involving the removal of all floor covering materials known or presumed to contain asbestos. P. Quirk, an asbestos consultant, recommended that "Floor tile and sheet removal must utilize wet methods for all work" (Ex. 3-34). A representative of the Resilient Floor and Decorative Covering Union expressed a similar view that "the floor should be kept adequately wet during the entire operation" (Ex. 7-37). Based on this support, OSHA has concluded that most flooring removals must be performed using wet methods when feasible and has included this requirement in the final with one exception. The exception allows floor tiles to be removed intact using heat.

Specific Work Practices for Specific Class II Operations

As discussed above, certain precautions are always required for all work under these construction and shipyard standards in paragraph (g)(1). These are HEPA equipped vacuums, wet methods, and prompt disposal of waste and debris. Additional provisions apply to the removal of all Class II material [Paragraph (g)(7)]. These are required critical barriers in designated indoor activities and dropcloths in all.

OSHA also includes more detailed work practices for specific Class II activities, such as the removal of roofing materials and resilient flooring material. Most of these requirements are more specific applications of general industrial principles for handling dust- generating materials, asbestos in particular. OSHA and many participants believe that employers are helped by specific work practice requirements so long as they do not restrict common sense accommodations to unique workplace conditions. The following discussion show the reasons for and support of OSHA's decisions for specific work practices for removal or disturbing ACM or PACM.

Flooring Operations

Flooring operations are separately discussed because of the amount of interest in these activities manifest during the rulemaking, and the prevalence of asbestos-containing flooring materials in buildings. Because of the prevalence of asbestos-containing flooring, the frequency which it is maintained and removed, and the possibility of exposure if improperly done, specific requirements for flooring are needed to reduce significant risk to the extent feasible.

Removal of asbestos containing flooring materials is a Class II asbestos job. As such, it must be performed using the operation specific controls set out in paragraph (g)(ii)(a), or when called for by an "exposure assessment using "alternative" controls. Additional controls must be used if the employer does not produce a "negative exposure assessment" prior to the beginning of the job, if during the job, there is reasonable belief that a permissible exposure level will be exceeded, or if methods are used which are expected to result in flooring material breaking or otherwise removed in a non-intact state. The required controls in large part mirror those of the proposal which were based on work practice recommended by the Resilient Flooring Covering Institute (RFCI). Additional "non-aggressive" practices are allowed, in response to supporting data and to commenters such as Michael Murphy of Monsanto who asked that OSHA "* * * allow the use of other practices which achieve comparable results" (Ex. 7-125).

OSHA believes that these provisions are necessary and appropriate to reduce risk to workers who perform this type of activity. The relative level of risk of removing asbestos-containing flooring was considered in the rulemaking. OSHA has not classified asbestos containing flooring as "high risk." The degree of risk from removing these materials depends on the kind of removal activity performed, and on the condition of the material. Data relating to flooring removal show overall lower levels than TSI and surfacing ACM (see e.g., Ex. 7-100; 7-132). Thus, EPA recently included resilient floor covering, in its lowest risk category (Category I non-friable ACM). However EPA concluded that "if these materials are in poor condition and are friable or they are subjected to sanding, grinding, cutting or abrading, they are to be treated as friable asbestos materials (55 FR at 48409). The OSHA record supports these findings.

Opinions of some asbestos abatement experts familiar with a range of asbestos removal projects agreed with the basis for EPA's and OSHA's classification scheme. Marshall Marcus stated that flooring removals, when well conducted are likely to involve lower exposures than removals of other types of interior asbestos containing materials; whereas Mary Finn emphasized that removing of flooring tile, because it cannot be saturated easily, may, when aggressively removed, result in significant exposures (see testimony of Marshall Marcus, Tr. 3794 and Mary Finn Tr. 3765).

OSHA's approach of requiring those removal methods which are unlikely to elevate exposures was challenged by participants who contended that methods for removing flooring cannot be determined at the beginning of the project. This might occur when employees discover during the project that flooring is resistant to removal. This may be difficult to predict in advance, as pointed out by BCTD (Ex. 143 at 155, citing testimony of asbestos contractor and consultant Marshall Marcus, Tr. 3794 and others). OSHA acknowledges that such difficulties may occur. However, as pointed out by Mary Finn, many of the variables contributing to exposures are available for consideration at the inception of the project; "* * * the predictability of how aggressive one must remove floor tile varies from job to job depending on the age of the particular materials, depending on the wear that it's undergone and depending on the techniques that the particular contractor and his workers might use" (Tr. 3744).

Also, OSHA notes that much of the project data submitted show consistency in practices over the entire project. In cases where more aggressive methods are resorted to mid-job, OSHA requires a "mid-course correction:" a re-evaluation of the exposure potential by the competent person, and the installation of additional controls if the projection is that the exposures will exceed the PEL.

Most "aggressive" techniques, such as "shot-blasting" may be used only after an evaluation showed that less aggressive methods are not feasible. Even if the evaluation of the "aggressive" method shows exposures will be below the PEL, the employees must still install critical barriers or otherwise isolate the removal operation [paragraph (g)(4)(i)(B)(2)], and employees must wear respirators. This is required regardless of when such "aggressive" methods were used, at the inception, or mid-way into a removal job.

Specific "non-aggressive" control methods are allowed and preferred for removing flooring materials (tile, sheet, and mastics) which contain asbestos and those materials for which the employer/ building owner has not verified the absence of asbestos. The controls are "non-aggressive" work practices, and include the practices which under OSHA's proposal would have allowed an exemption from the requirement to erect a negative pressure enclosure for flooring material removal (see 55 FR at 29719).

OSHA did not propose to require employers to assume that vinyl or asphalt tile or resilient flooring was asbestos containing, although the RFCI recommended that such an assumption be made. OSHA asked for comments on this issue.

Several industrial hygienists agreed that the recommendation should be followed. For example, David Kirby, industrial hygienist, Oak Ridge National Laboratory, testified that an ongoing survey of ORNL facilities showed that "90 percent of our floor tile either contained asbestos or the mastic material that's used to attach them to the floors contained asbestos." Mr. Kirby recommended that it's "prudent to * * * assume that all floor tile materials contain asbestos, unless you can prove the contrary * * *" (Tr. 124-125). According to Mr. Kirby, negating the presence of asbestos content in flooring material entails a complex and expensive process; "taking those materials, having them ashed, using high temperature ashing techniques, and then the residue could be analyzed by transmission electron microscopy." Other evidence in the record indicated the prevalence of asbestos containing flooring material. An EPA 1988 survey, cited in the HEI report, reported that 42% of public and commercial buildings within the U.S. contain asbestos containing floor tile (Ex. 1-344).

A review of the comments and evidence demonstrates that there is a high degree of prevalence of asbestos-containing flooring and that there are diagnostic difficulties in identifying asbestos fibers in flooring material. Consequently, OSHA is changing its approach and the final standard provides that the employers shall assume in removing flooring that it contains asbestos and take the specific precautions unless the employer demonstrates that the flooring materials are not asbestos-containing. Such a showing must be based on analysis which is likely to reveal the asbestos content of the flooring material, the backing and the mastic. No one protocol for analysis is specified, but the standard requires that a certified industrial hygienist (CIH) or project designer certify the analytical results.

OSHA believes that the final standard's provisions relating to flooring removal are more comprehensive and protective than the proposal's. There, an exemption for flooring removals from the NPE requirement was conditioned merely on compliance with certain work practices recommended by the Resilient Floor Covering Institute (RFCI). These practices included a prohibition of sanding of floor or backing, use of a HEPA vacuum cleaner before and after removal, prohibition of dry sweeping, application of new material over old tiles without removal if possible, wet removal of residual felt, and bagging and disposal of waste in 6 mil plastic containers. The new final provisions allow removal to be performed by these methods, but also allow various heating methods to be used, or any other means of loosening floor tiles, without breakage. Unlike the proposal, an employer cannot proceed without negative air or critical barriers, merely using non-aggressive work practices and wet methods, unless his pre-job evaluation shows that similar floor removals (in the same building or of the same materials and mastics) were successfully completed by work crews with adequate training and experience in working under these conditions.

OSHA noted in the proposal that data provided by RFCI showed that where jobs followed their recommended practices, mean exposures to workers were between 0.0045 and 0.03 f/cc for workers performing floor tile removal, removal of resilient sheet flooring, or removal of cutback adhesive. During the rulemaking, additional data were submitted showing exposure levels during flooring removals. David Kirby, OSHA witness from Oak Ridge National Laboratory (ORNL) said that he has used the RFCI work practices successfully, maintaining personal sampling fiber levels at an average of 0.0075 f/cc (range 0.001 to 0.029) (Tr. 99). When asked what additional precautions were taken at his facilities during these operations, he replied that "we do use regulated areas in the sense that we don't allow anyone in the area as we're doing the work, and we also require workers to wear respiratory protection as they're doing this activity, but yet we don't feel like there is * * * a need for negative pressure enclosures." (Tr. 124). BCTD, in its post-hearing brief argued that the RFCI methods specifically, and "non-aggressive" flooring removal methods generally, do not always result in exposure levels which are acceptable (Ex. 143). It cited various studies or project results submitted to the record. Some of these results were given in terms of structures per square centimeter, a convention of TEM. For example, Richard Kelly of Lawrence Livermore National Laboratory objected to allowing the use of RFCI methods to control asbestos exposure during removal of asbestos containing mastic (Ex. 11, #22). He reported that during removals in which only the mastic contained asbestos, he had measured (by TEM) fiber levels of 33 s/cc during dry power chipping of VAT and 0.9 s/cc during wet hand removal in what he called a "real-world application of the RFCI procedures." He noted that the floor was not pre-vacuumed nor was a heat gun used as described in the recommended practices. Under its AHERA rule, EPA defines "structure" as a microscopic bundle, cluster, fiber or matrix which may contain asbestos. OSHA notes that such structures may be smaller and/or thinner than the asbestos fibers required to be counted under the OSHA reference method. A general summary of the results of these studies shows that most of the exposure levels were below the proposed PELs when measured using the OSHA reference method (e. g., Gobbell, 1991, exposure range, 0.01 to 0.035: AT &T, 1990, non-detected to 0.019).

Some other studies of floor removals entered into the record showed higher exposure levels of "structures" as detected by TEM, and defined by EPA. As noted above, counts of structures are not comparable to fiber counts, and OSHA believes that most "structure" counts result in significantly higher fiber counts than would be counted by PCM.

A related issue is whether flooring material should be analyzed by TEM, rather than by PCM. As pointed out by BCTD and other participants, floor tile tends to generate smaller fibers which often cannot be detected under PCM; and TEM detects these shorter asbestos fibers (and the thinner asbestos fibers, which PCM cannot distinguish [Ex. 143, p. 147 citing Tr. 3468; Tr 3751, Tr. 3279, Tr. 473-474]. In the 1986 rulemaking OSHA considered the issue of the relative toxicity of short asbestos fibers, which were not required to be counted under the OSHA definition of "fiber." Then, the Agency stated that "* * * animal studies * * * in particular the recent work by Dr. Davis, point to a clear relationship between fiber dimension and disease potential. The finding in these studies that thin fibers, (having an aspect ratio of at least 3:1) greater than 5 um in length are associated with elevated incidence of cancer and lung fibrosis is also consistent with current knowledge regarding lung clearance mechanisms, i.e., that shorter fibers are easily phagocytized and removed from lung tissue" (51 FR at 22613). Dosages used in OSHA's risk assessment extrapolated from studies of human exposure, attempted to transform or reconstruct fiber counts to correlate with fiber counts using current conventions of counting fibers only longer than 5 um, using PCM. Similar to the conclusions reached by OSHA in the preamble to its 1986 asbestos rule, the HEI report of 1991 found that "experimental results described in this review indicate that short fiber preparations have a lower toxicity than long fiber preparations, but do not exclude their contribution to the lesions caused by the smaller number of long fibers in the tail of the fiber length distribution * * * individual fibers shorter than approximately 5 um appear to possess much less toxicity than those longer than 5 um" (Ex. 1-344, p. 6-76).

The HEI Report also noted that the exposure-response relationship reported in the literature which served as the basis for estimation of risk had exposure expressed in terms of fibers greater than 5 um in length (Ex. 1-344). These aspects of OSHA's risk assessment, and counting protocols were not challenged in the litigation following the 1986 rules, therefore were not remanded to OSHA for reconsideration in the Court of Appeal's 1988 decision. The only study submitted in its entirety, (see Freed et al, Ex. 143 at Att. B), is of limited relevance; it is a case study, which was undertaken to show that asbestos fiber may produce DIP (desquamative interstitial pneumonia) as well as asbestosis. The authors note that "although over 90% of the 820 million fibers of wet lung tissue were 3 um or less in length, sufficient numbers of fibers greater than 5 um in length were present, which could also account for the tissue response" (Ex. 143, Att B at 332). Resolution of whether short or long fibers are counted is not necessary for the purposes of this revised standard, because OSHA finds that work practices and controls are needed when working on floors regardless of the measurement method used. OSHA does not change its conclusion and retains the provisions that airborne asbestos measurements taken during flooring operations shall use the same methodology as in the 1986 standard.

The Agency's analysis of data submitted showing exposure levels during flooring removal, shows a general correlation between lower levels and "non-aggressive" methods, and higher levels and "aggressive methods." For example, Mary Finn of Chart Services, an asbestos consulting company, testified that "if breakage is minimized, obviously exposures are going to go down" (Tr. 3765). Ms. Finn submitted area sampling data from flooring removal operations which had a mean of 0.056 f/cc as an 8-hour time-weighted average (Ex. 9-18). She also presented data on area TEM counts taken during four operations involving drilling through VAT -- the mean for the four samples was 0.3 structures/cc (2 samples were below the limit of detection and one value was 1.01 f/cc), while all four samples were below the limit of detection when measured by PCM. BCTD cited various studies showing high fiber levels during flooring removal (Ex. 143 at 151-153). One, the Cook data, showed some high short term levels on one job, it was unclear what work practices were used, other jobs done by the same firm showed exposure values less than the PELs (see Ex. 35 and 119S). The Rosby data showed short term data which were well within the PEL excursion limit (Ex. 119 U). Other data pointed to by BCTD as indicating the unreliability of exposure reductions using non-aggressive methods, merely shows that EPA clearance levels were not achieved (Ex. 7-132), that exceedances were possible (Ex. 7-137 [it is noted that an exposure of .11 f/cc is considered in compliance with OSHA's PEL, and that TEM fiber counts were elevated (Ex. 119T)].

In addition to the Environ data contracted for and submitted by RFCI and Armstrong, which was interpreted differently by the submitter and by BCTD, these and other interested parties submitted additional data showing exposure levels during various kinds of asbestos-containing flooring removal. Low exposure levels were obtained in a New York State Department of Health Study, for floor tile removal using automated infrared heating, (followed by hand scraping)(see Ex. 7-100). As noted above, OSHA is allowing removal to be performed using heat, so long as tiles are not broken during the removal process. Under contract with EPA, PEI Associates performed a study which was described in a report entitled "Evaluation of Tile and Mastic Removal at Fort Sill" (Ex. 1-330). TEM was used to measure fiber levels resulting from use of several different methods to remove tile and/or mastic. They found that "airborne asbestos levels averaged 0.135 structures per cubic centimeter (s/cc) during dry tile removal, 0.066 s/cc during wet tile removal, 0.247 s/cc during removal of mastic using citric acid and towels and 0.326 s/cc during sand machine mastic removals. No PCM measurements were presented, and the proportion of the TEM-measured fibers exceeding 5 um in length was not reported.

The question of whether a negative pressure enclosure should be required for floor tile removal, was considered during the rulemaking. Some participants, including asbestos abatement consultant, Marshall Marcus recommended negative pressure enclosures as a matter of course for asbestos containing flooring removal (See e.g., Tr. 3796 and Ex. 7-37, 7-92). OSHA notes that its final rule now requires bystander protection, when excessive exposure levels are measured or expected. The questionable benefits to flooring removal employees of working within a enclosure are discussed in the general discussion on NPEs in this preamble. OSHA also notes that some exposure data submitted concerning flooring removal exposure levels, contained relatively high exposures for work within enclosures (see e.g., Ex. 7-134A) and that removing flooring using dry ice in a negative pressure enclosure can result in toxic buildups within the enclosure (see Tr. 202). Therefore OSHA is not generally requiring flooring removal to be done within NPEs. However, where flooring material is removed using "aggressive methods," higher fiber levels have been reported, at least as measured by TEM (see Ex 11, #22 and 9-18). The Agency concludes that the use of aggressive floor removal techniques in which the material is not removed intact, such as mechanical chipping of floor tile and shot-blast removal of mastic, are likely to result in the release of larger amounts of fibers and must be performed within negative-pressure enclosures or the equivalent. EPA has concluded similarly:

Removal of VAT (or other known or assumed ACM flooring or its adhesive) which involves sanding, grinding, mechanical chipping, drilling, cutting or abrading the material has a high probability of rendering the material friable and capable of releasing asbestos fibers. Therefore, removal projects which employ any of these techniques (other than small-scale-short-duration) must be conducted as response actions, including use of a project designer, accredited persons, and air clearance (55 FR 48409).

In response to concerns that the RFCI work practices will not be followed, it should be pointed out that the alternate to their use is full enclosure of the operation which is likely to be considered more burdensome than the work practices.

Transite Removal

Removal of transite panels is considered a Class II activity in this revised standard. As such, they are required to be removed using certain practices and controls. These are: the intact removal of transite panels; the use of wet methods followed by wrapping of the panels in plastic; and the lowering of panels to the ground without breakage. These provisions are in essence the same one proposed by OSHA in 1990 when allowing an exemption from the NPE requirements. The 1990 proposal presented the comments of OSHA field personnel which suggested that removal of transite panels, without regard to quantity, should be exempt from the negative-pressure enclosure requirement as long as the transite is removed without cutting or otherwise abrading the material (Ex. 1-59). This suggestion was supported by numerous participants (Ex. 7-6, 7-9, 7-23, 7-42, 7-43, 7-47, 7-52, 7-62, 7-63, 7-74, 7-79, 7-86, 7-95, 7-99, 7-103, 7-106, 7-108, 7-111, 7-112, 7-125, 7-128, 7-134, 7-144, 7-146, 7-140).

Additional work practices such as wrapping panels and lowering them intact, were suggested in this proceeding and are incorporated in the revised standards [see comments of Robert Welch of Columbia Gas System who recommended wrapping intact transite panels in sheeting and lowering them intact to the ground avoiding breakage (Ex. 7-23); and, comments of Edward Karpetian of the Los Angeles Department of Power and Water, who recommended that in addition, the material be HEPA vacuumed and wrapped (Ex. 7-42)]. As noted in prior discussion of the general provisions covering construction activities, negative pressure enclosures are not required for Class II activities, unless they are performed along with a Class I activity for which an NPE is required.

The rulemaking record contains strong evidence showing low exposures resulting from transite panel removal when appropriate work practices are followed. The submission of the American Paper Institute and the National Forest Products Association contained sampling data taken during the removal of transite panels from paper machine hoods (Ex. 7-74). Wet methods were used and the area was regulated. Personal and area samples were well below 0.1 f/cc, with the 23 personal samples having an average of 0.012 f/cc (not time-weighted). Rose Simpson of Lubrizol stated that "area monitoring samples taken during transite removal operations at our facilities indicate exposure levels well below the current 0.2 f/cc and the proposed 0.1 f/cc limits" (Ex. 7-86). OSHA witness David Kirby of Oak Ridge National Laboratory stated in his comments that personal air monitoring during transite panel removal resulted in average fiber level of 0.008 f/cc (8 hr. TWA) (Ex. 7-111). And in a post-hearing submission (Ex. 105), he presented the fiber levels (measured by PCM) generated during non-enclosed transite removal performed wet at ORNL, which ranged from < 0.031 to < 0.082 f/cc (mean = 0.058 f/cc) (see also Ex. 140, where the Dow Chemical Company claimed transite removal real time levels did not exceed 0.07 f/c).

As described above, most data show that if performed intact, transite removal will result in exposures well below the PELs. Some evidence, however, was presented showing exceedances. Paul Heffernan of Kaselaan&D'Angelo Associates, Inc. stated:

* * * removal of transite panels which are not cut or broken should not be generically allowed. Many transite panels used in interior wall construction consist of very rough inner surfaces from which asbestos fiber is readily released into the air. Kaselaan&D'Angelo Associates has monitored the removal of 18" by 36" transite panels which were held in place with screws. The transite panels were removed intact by removing the screws and lifting the relatively small panels to the floor where they were placed in boxes. The exposed surface of each panel was first wet with amended water before removing the screws. The job was performed within negative pressure containment. Airborne fiber levels exceeding 1.0 f/cc were measured. Transite panel removal has potential for fiber release even when the panels are not broken (Ex. 7-36).

As noted above in the flooring material discussion, OSHA is requiring job by job evaluation of each Class II job, including transite panel removal projects, by a competent person, as part of the requirements to perform an initial exposure assessment. As detailed above, the data submitted to the record show that transite panel removal without cutting usually results in very low exposure levels. Building and facility records of past removals of similar material will alert on-site competent persons to the exposure potential of the panels in their facilities. For rare cases, when the evaluation of material, condition, crew and past exposure data do not support a "negative exposure assessment," (i.e., that excessive exposures may be expected), additional precautions are required by the standard, including critical barriers, and respirator use.

OSHA believes that these provisions will protect employees against significant exposures, are feasible, and are supported by the record. In particular OSHA finds that quantity limitations on transite panel removal would not tend to reduce risk, and in some cases may increase fiber levels. For example, Richard Olson of Dow Co. pointed out that if transite panel removal were to be exempted from the negative pressure enclosure requirement and the cutoff remained at 9 square feet as proposed, it would be necessary to cut nearly every piece of material removed or always use a negative-pressure enclosure (Ex. 7-103).

Cementitious Asbestos-Containing Siding (CACS)

The removal of cementitious asbestos-containing siding is a Class II activity. OSHA is requiring the same work practices for shingle removal as for transite panel removal. OSHA did not propose specific work practices for removal of CACS, either to exempt this activity from the negative pressure enclosure requirement or to qualify as a SSSD activity. However, many participants representing a wide spectrum of interests, including states, federal agencies, and asbestos industry organizations, recommended that OSHA exempt CACS removal from the requirement to establish negative-pressure enclosures; (See e.g. asbestos coordinator for Florida (Ex. 7-6); Navy Office of Chief of Operations (Ex. 7-52); Asbestos Information Association/North America (Ex. 7-120); New York City Department of Environmental Protection (Ex. 126); and, The Army Corps of Engineers who also submitted the data from a study of fiber levels generated during CACS removals Ex. 1-307).

In the Army Corps of Engineers' study cited above, three mechanical CACS asbestos removal methods and the manual method were evaluated by monitoring during removal of the siding. The three methods were: 1) super wet: the siding was thoroughly wetted with water on the outfacing and back side; 2) mist: a measured amount of water was applied to the outfacing side of the siding only; and, 3) encapsulation: an EPA-approved commercially available encapsulant was applied at or above the recommended application rate. These removals took place inside enclosures and the hand method was also evaluated. Samples were measured using TEM and results of area samples indicated all were less than 0.005 or below the limit of detection. Two personal samples taken "while removing cement-asbestos siding shingles from Building 523" yielded 8 hour time-weighted averages of 0.008 and 0.012 f/cc.

Other data show low exposures during CACS removal. One where approximately 110,000 square feet, in total of CACS were moved from 43 college campus dormitory buildings prior to demolition. The average bulk analysis of the CACS was 17%. No outdoor area samples were higher than 0.01 f/cc by PCM for the duration of the project. The 80 personal samples collected during the project had an arithmetic average of 0.049 f/cc with a standard deviation of 0.041. The geometric mean was 0.04 f/ cc with not TEM data available (Ex. 7-132A). The study authors concluded that "CACS removal, even though outside where dilution is assumed significant, should be done carefully, using as a minimum the abatement techniques described in this paper." These included wetting, dropcloths, and a 20-foot wide regulated area. OSHA agrees and believes that the methods required by the standard will reduce risk significantly for exposed workers.

Results of this study and others show that CACS removal can be performed using work practices which minimize exposure to workers and that containment in NPEs is neither necessary or appropriate in most cases to protect the workers performing the removals or working nearby. However, it is clear that Class II work practices are necessary to keep exposures low.

OSHA has coupled CACS removal with transite panel removal in the regulatory provisions establishing mandatory work practices for the removal of these materials.

Roofing Operations

The final construction standard classifies removal of roofing material which contains asbestos as a Class II operation. As such, specific exposure assessment and work practices must be performed. The record shows that these work practices can be feasibly implemented and are necessary to effectively reduce airborne asbestos levels from roofing removal projects. They consist of continual misting of cutting machines during use, keeping roofing materials intact during removal, using wet methods, immediately lowering unwrapped or unbagged roofing material to a covered receptacle using a dust-tight chute, or immediately wrapping roofing material in plastic sheeting, and lowering it to ground by the end of the work shift.

In addition, unless the employer can demonstrate that it is not feasible, the roof level heating and ventilation air intake and discharge sources must be isolated, HEPA filtered, or extended beyond the regulated area, or mechanical systems must be shut down and vents sealed with 6 mil plastic. OSHA has taken into account concerns that isolating air intakes may cause heat build-up in the building (Ex. 7-7). As for all Class II work, respirators must be worn if material cannot be removed in an intact state, or if wet methods are not used. In addition, regulated areas must be established pursuant to the provisions of paragraph (e).

These provisions are similar to the conditions proposed by OSHA which would have allowed an exemption from the proposed negative pressure enclosure requirement providing implementation of specific control methods which would have applied to all non-exempt removal jobs. In the proposal, the Agency stated that it did not believe that requiring use of negative pressure enclosures on roofs would result in more than a de minimis benefit to workers removing roofing or to other employees in their vicinity. That the safety hazards which might be imposed by their use on roofs would outweigh the benefits (55 FR at 29719). The Agency proposed that employers engaged in roofing operations take additional steps to reduce employee exposure to asbestos. These steps included use of dust-tight chutes to lower debris from the roof to the ground, or immediate bagging and lowering of debris rather than dumping it from a height. Wetting would also be required where feasible to reduce contamination. The Agency felt that these measures had been shown to be effective in reducing employee and bystander exposures during roofing operations.

There was general support for the exemption of roofing operations from the NPE requirement (Ex. 7-1, 7-12, 7927, 7-36, 7-39, 7-43, 7-52, 7-95). BCTD acknowledged that negative-pressure enclosures are infeasible for most roofing operations. OSHA also believes that categorizing roofing removals as Class II work is well supported by the record. Some data show exceedances of the new PEL in roofing operations (see Ex. 9-34 QQ, cited by BCTD, Ex. 143 at 135). Other data show roofing removals, where proper work practices are followed, generate low exposure levels, e.g., data submitted by NCRA, collected by SRI shows many exposures were below the revised PEL, most jobs used wet methods (Ex. 9-31A).

A health survey submitted by the BCTD showed asbestos related diseases and deaths among roofers in the period from 1976-1989 (Ex. 119 QQ). That study is evidence that proper protective practices are necessary to protect workers. However, diseases resulted from past exposures both removing and installing asbestos-containing roofing without protective requirements and do not necessarily predict worker health from lower exposures resulting primarily from removal work performed more protectively.

In addition participants supported required work practices (see Ex. 7-120, 7-132, 7-36). BCTD preferred adoption by OSHA of the recommendations made by the labor representatives of ACCSH which are more rigorous than the work practices proposed by OSHA. The additional practices would include: establishing the entire roof as a regulated area; cutting or removing ACM using hand methods whenever possible; equipping all powered tools with a HEPA vacuum system or a misting device; HEPA vacuuming all loose dust left by the sawing operation; and, isolating all roof-level air intake and discharge sources, or shutting down all mechanical systems and sealing off all outside vents using two layers of 6 mil polyethylene (Ex. 34). As noted above, OSHA has adopted most of these additional work practices in the final regulations. OSHA is not requiring the entire roof to be designated as a regulated area: the portion to be removed may be a small part of the entire roof. The regulated area should encompass that portion of the roof where dust and debris from the removal is likely to accumulate.

One issue concerning required controls is whether OSHA should prohibit power cutting on roofing materials containing asbestos. Information in the record is inconclusive on whether power cutting usually results in higher exposure levels than hand cutting. A representative of the National Roofing Contractors Association (NRCA) testified that "we're finding extremely low readings (on the power cutter); * * * it appears to us that the cutting of the material seals the edges because of the heat of the blade of the cutter, mixing with the asphalt" (Tr. 2427). Other data were submitted to show that power cutting elevates asbestos fiber levels compared to hand cutting; however OSHA believes that some of these conclusions may overstate the results of limited experimentation. For example, one study was presented as suggesting that power cutting elevated fiber levels over hand cutting (Ex 1-357). OSHA regards this study as not definitive. The differences in fiber levels in the breathing zones of workers were only marginally statistically significant, and there was another variable in the study's protocol which may have effected the outcome. OSHA recognizes the bound nature of the asbestos in most roofing materials, however, it also understands the physical principles involved in cutting of these materials and that such actions release fibers.

Because of this mixed record, OSHA concludes that no prohibition of power cutting is called for as long as the other specified precautions including misting are carefully followed. The standard allows power cutting, but also requires that sections of roofing material shall be cut into the largest pieces which can be feasibly handled for disposal pursuant to the standard. Requiring misting of power tools in all situations except where a competent person determines that misting may decrease safety is expected to help reduce exposure levels from power cutting.

The general requirement that all asbestos work be performed wet, unless the employer can demonstrate lack of feasibility applies to roofing operations. A discussion of this provision is found above in the discussion on paragraph (g)(1)(i)(B). As noted there, "flooding" is not required; "misting" of cut areas is sufficient to control dust.

OSHA believes that these precautions are necessary to protect employees who remove roofing materials against elevated exposures in normal circumstances. The record shows, however, that elevated exposures may occur where damaged or friable roofing material is removed. [See SRI report, recommending the use of respirators where roofing material is "uncharacterized and aged" (Ex. 9-31A at 20)]. Under such circumstances, the competent person's determination must be that the normal precautions are not sufficient. Steven Phillips, counsel to the NCRA agreed: "(w)hen you're working with uncharacterized and aged roofing materials, that is * * * where you have no idea what the exposures may be because you have no historical data; you haven't worked with that particular material; * * * (there are) the normal OSHA requirements of doing initial job site monitoring and having respirators until you have good, reliable, job site monitoring" (Tr. 2463). In such atypical circumstances, additional precautions, including respirator use and more extensive wetting, will be necessary. NRCA's objection to the routine use of respirators on roofing jobs, as recommended by BCTD, was based on its view that respirator use on roofs often compromises worker safety, because respirators reduce "downward visibility" of the wearer (Tr. 2463). OSHA agrees that in some roofing conditions, limitations from wearing respirators might occur. When respirator use is necessary because of the condition of the roofing material, but respirators cannot be safely worn because of great heat, cold, or high winds, etc., such roofing jobs shall not be performed until they can be done safely. The Agency has concluded that "routine" respirator use is not required, because as discussed above the required work practices will keep exposures low in normal circumstances; but where historic data, experience of the crew, or the condition of the roof indicate the possibility of higher exposures, then respirator use is required.

Various studies which were submitted support OSHA's classification of roofing removal as a Class II activity. They show that most measured exposures are lower than many studies showing removal of Class I materials; but still may be significant. In most cases levels below the new PELs can be routinely expected with minimum controls.

SRI evaluated air monitoring reports from 79 roofing removal operations, 560 personal and 353 area samples (Ex. 9-31). All samples, except 24 were well below the new PEL of 0.1 f/cc. Fourteen samples were collected for 30 minutes or less (and were below the excursion limit). When the remaining sample measurements were calculated as 8 hour time-weighted averages, they also did not exceed the PEL. The remaining samples did not exceed 0.1 f/cc. The contractors concluded, "there appears to be no pressing need for air monitoring at the start of each job, negative pressure enclosures, or wetting. However the use of half-mask respirators is recommended until the source of the fibers in the few samples where concentrations were above 0.1 f/cc can be defined." They added that "exposure to asbestos should be minimized until more (or better) information is available; the use of respirators seems a prudent compromise when working with uncharacterized and aged roofing materials."

The submission of Preston Quirk of Gobbell Hays Partners, Inc. included a study entitled "Airborne Levels During Non-Friable Asbestos-Containing Material (ACM) Removal" which was presented at the 1990 meeting of the National Asbestos Council (Ex. 7-133a). One section of this study presented the sampling measurements taken during removal of asbestos-containing roofing felt and flashing using a wet prying and peeling technique with no enclosure. Five area samples averaged 0.007 f/cc by PCM and 0.008 s/cm3 by TEM. Five personal samples averaged 0.024 f/cc by PCM and 0.304 f/cc by TEM. It was reported that the personal TEM samples had 0.124 s/cm3 of structure greater than or equal to 5 um.

BCTD submitted a study by D. Hogue and K. Rhodes entitled "Evaluation of Asbestos Fiber Release from Built-up Roof Removal Projects" (Ex. 34, VV) in which roofing operations were monitored using both PCM and TEM methods of measurement. The authors stressed the "non-scientific" nature of the study and noted that they had measured only a limited number of samples. They described a project involving removal of a 15% asbestos roof from a hospital in which a several control methods were used. Area samples were taken at "high," "medium," and "low" locations and most were measured using the PCM method. During mechanical removal, the arithmetic mean concentration was 0.16 f/cc (not time-weighted); and during manual removal the average was 0.1 f/cc (non-weighted). Personal samples were measured only by TEM and the 3 taken during manual removal averaged 0.11 f/cc (also not weighted). In another section of this report the authors describe a "Controlled removal of asbestos containing built-up roofing materials without containment with engineering and work practice controls and extensive sampling and analysis by transmission electron microscopy," however, the specific engineering and work practice controls employed are not described. Nonetheless, the resulting measurements, both PCM and TEM, are well below the PEL except one sample in which the TEM concentration was 0.1 s/cc.

NIOSH described an evaluation of airborne asbestos fibers during the tear-off of an old asbestos shingle roof from a residential building (HETA 84-321-1590, Ex. 44). Seventeen personal breathing-zone samples were collected for approximately two hours. For 5 tear-off workers the fiber concentrations ranged from 0.04 to 0.16 f/cc, arithmetic mean 0.09 f/cc; for two clean-up workers the fiber concentrations ranged from 0.13 to 0.16 f/cc, arithmetic mean 0.14 f/ cc; and, for the 5 workers applying new shingles the concentration ranged from 0.03 to 0.08 f/cc with a mean of 0.05 f/cc. In this evaluation, NIOSH concluded that there was a hazard from exposure to airborne asbestos fibers during the tear-off of an asbestos shingle roof and recommended several practices to reduce worker exposure.

OSHA notes that in some cases, the author of the above studies recommend more rigorous controls than the final standards require. Largely, this was based on evaluations of roofing removal exposure potential based on small numbers of TEM measurements. As stated elsewhere in this document, OSHA has based its risk assessment, and relative exposure profiles on the results of many studies which relied on PCM values. OSHA considered TEM in the 1986 standard and concluded that it was quite expensive and not fully validated. More importantly, OSHA believes that the roofing studies submitted show the relatively low levels of asbestos fibers emitted during removal work when proper controls are used. The small number of exceedances which occurred reflect poor work practices and "uncharacterized and aged material."

The purpose of the regulated area in the asbestos standards is to prevent asbestos contamination of other parts of the workplace and to limit exposure to only those specially trained employees who need to work in the area. While OSHA does not want to shut down the entire building when asbestos work is done on the roof, asbestos entering the ventilation system during roofing work is clearly unacceptable. OSHA expects good judgment to be used by the competent person in striving to achieve the intent of the standard. OSHA requires that roof level heating and ventilation air intake sources must be isolated. The employer would also have the option to shut down the ventilation system and seal it with plastic. Only necessary work should be done on the roof while asbestos materials are being removed, and the locations of the work should be selected to minimize exposures, such as upwind of the asbestos work. OSHA agrees that the 20 foot barrier approach recommended by Mr. Collins (Ex. 7-52) has merit, but believes the exact determination should be made on site, and could vary depending upon working conditions.

OSHA concludes that removal of roofing material containing asbestos requires the use of controls to reduce significant risk. Simple procedures will reduce exposure levels substantially and, for the most part, will reduce levels below the PELs. OSHA believes that it is appropriate to require specification work practices for removal of asbestos-containing roofing material, regardless of measure exposure levels. As discussed above, these controls were recommended by rulemaking participants, although there was some disagreement regarding the need for some of the controls.

The final standard requires the use of wet methods and continuously misting cutting machines during use and loose dust left by the sawing operation is to be HEPA vacuumed immediately. Some commenters were concerned that water could create safety hazards, so the standard reflects that the competent person could determine that misting the cutting machine, or other wet methods, should not be used. If wet methods are not used the respiratory protection provision of this standard, paragraph (h) requires that respirators be used regardless of exposure level. This provision is based upon OSHA's finding that dry disturbance or removal of asbestos containing material has large potential to expose workers and is in accordance with that of EPA NESHAP. Other controls include removing the roofing material in an intact state to the extent feasible, immediately lower unbagged or unwrapped roofing material to the ground via dust-tight chute, crane or hoist, or wrapping the roofing material in plastic sheeting and lowering it to the ground, transferring materials immediately to a closed receptacle in a manner so as to preclude the dispersion of dust, and sealing off air intakes to the building prior to doing any roofing removal.

OSHA concludes from the studies that exposures can go over the PEL and create significant risk in circumstances when appropriate precautions are not take. Consequently, they support OSHA requirement for some specific work practices in all circumstances.

Methods of Compliance for Class III Asbestos Work

The newly revised construction and shipyard employment standards continue to regulate exposure to employees engaged in repairing and maintaining building components which contain previously installed asbestos containing material. In the 1986 construction standard, most of these jobs were called "small-scale, short-duration operations," but, as discussed above, OSHA was instructed by the Court of Appeals to clarify the cut-offs for that designation. Now, OSHA has determined that separate regulatory treatment of repair and maintenance operations will not be limited by arbitrary duration and amount-of-material-disturbed criteria. Instead, they are called "Class III operations," and are defined as "repair and maintenance operations which may involve intentional disturbance of ACM, including PACM" (see Green Book, Ex. 1-183). The major difference between the newly revised repair and maintenance definitions, is that the amount of material and/or the time the operation takes are no longer the criteria for inclusion in the class.

The revised and expanded definitions of the various terms in the Category III definition enhance its clarity. Since Category III includes maintenance, repair, some renovation and other operations which disturb ACM, and PACM, a definition of "disturb" is provided. Although "removal" activities are designated Category I or II, the incidental cutting away of small amounts of ACM or PACM to access mechanical or structural components for repair or maintenance, is considered Category III.

Examples of work which are considered Category III are contained in various studies submitted by participants to prove or disprove how risky asbestos disturbing repair and maintenance work is. OSHA has evaluated the data from a number of sources to estimate the degree of exposure of workers to previously installed asbestos building material during various types of activities. Most studies showed lower levels of exposure than Category I and II work. For example, the Safe Building Alliance submitted a study by its consultant Price (Ex. 151). He compiled sampling data from numerous sources including OSHA compliance data, and obtained questionnaire information from building owners. The questionnaires solicited information on the frequency and duration of specific activities. These activities included, maintenance/repair of boilers, air handling units, heat exchangers, tanks; repair/replacement of pipe insulation including removal of small amounts of ACM; and, valve or gasket replacement, of activities above suspended ceilings such as connections and/or extensions for telecommunication/computer networks; adjustment/repair of HVAC systems; and, testing/cleaning/ replacing smoker or heat detectors. The final activities which may result in ACM contact such as repairing/replacing lighting fixtures and replacing ceiling tiles. The data were used to calculate potential exposure hours (PEH) which is the product of the annual frequency of an activity and the duration of that activity in hours. For all activities in all buildings in the data set, Price calculated a PEH of 91 hours per year and a PEH per worker of 19 hours per year per worker. Eight-hour time weighted averages were also reported as presented in Table III.

Table III. -- Asbestos Fiber Levels During Maintenance Activities

[Ex. 151]
Location of activity 8-hour TWA Median PEH PEH/ worker
Above ceilings 0.029 13 5
In utility spaces 0.031 13 2
Other 0.018 6 < 1
OSHA data 0.027
All activities 74 19

Price concluded that small-scale, short duration activities take up a relatively small proportion of a typical worker's time in that in 80% of the buildings he studied, less than 22% of total time is spent on these activities in a year, and that "on a per worker basis, in 80 percent of the buildings the number of potential exposure hours total slightly less than 4 percent of a work year" (Ex. 151, Appendix A, p. 12).

OSHA notes that BCTD objected to various aspects of the Price study in its post-hearing brief (Ex. 143) and concluded that the study "demonstrated that in some buildings exposure hours can be very high * * *" (Ex. 143, p. 112). However, OSHA views the study as supporting its view that when properly controlled, most kinds of routine maintenance involving ACM results in low exposure levels.

A recent study by Kaselaan and d'Angelo Associates for Real Estate's Environmental Action League in 1991 was reviewed (Ex. 123). The contractors looked at historical data from 5 commercial buildings in which the activities sampled were reported as "small-scale, short duration." The operations were performed "almost exclusively" within mini-enclosures and most were performed by "trained and experienced asbestos abatement workers, who are more used to the larger full-scale asbestos abatement procedures" and not by building maintenance workers. The data are summarized in Table IV.

Table IV. -- Asbestos Fiber Levels in 5 Buildings During
"Small-Scale" Operations

[Ex. 123]
Building designation No. of sam- ples Average exposure 8 hr.TWA
One-C 76 0.073 0.025
1500 25 0.055 0.01
645 49 0.011 0.003
28 19 0.02 0.003
1114 7 0.023 0.007
  • (From Ex. 123, p. 1)

The authors also pointed out that because air monitoring and third party oversight during these activities, they probably represented situations in which proper precautions were taken. They concluded that "the data presented indicates the necessity of controlling asbestos exposure during the type of [small-scale, short duration] activities represented in this study. However if appropriately performed * * * exposures well below the current OSHA exposure limits can be maintained" (Ex. 123, p. 26).

Table V. -- Asbestos Fiber Levels During Various Maintenance Activities
Type of work Personal samples:
No. of samples Mean Range
Air handling unit preventive maintenance 87 0.0942 0.0087-0.6805
Miscellaneous repair 48 0.1272 0.0039-0.5496
Miscellaneous installation 20 0.1742 0.0049-0.8395
Clean-up of ACM debris 8 0.2030 0.0414-0.6246
Cable pulling 9 0.0544 0.0240-0.0985
Relamping 9 0.0469 0.0205-0.0929
Generator testing 18 0.0843 0.0075-0.2261
Fire alarm testing 4 0.1654 0.0836-0.2693

OSHA also notes that although exposures ranges above the PEL for some activities, mean levels were, in most case, much lower.

Dr. Morton Corn of Johns Hopkins University submitted summaries of monitoring results from samples taken during a variety of operation and maintenance activities from 5 buildings (Ex. 162-52). The 8-hour time- weighted averages of the personal samples for each building are presented in the Table VI.

Table VI. -- Asbestos Fiber Levels During O&M Operations in 5 Buildings

[Ex 162-52]
Operation/building # 1 2 3 4 5
Ceiling removal/installation 0.015 0.003 0.008 0.03
Electrical/plumbing work 0.06 0.003 0.006 0.008 0.04
HVAC work 0.02 0.003 0.01 0.02
Miscellaneous work 0.008 0.004 0.01 0.09
Remove/encapsulate 0.06 0.003 0.002
Run cable 0.02 0.002 0.08 0.01 0.03
8 Hour Time-Weighted Averages
Personal Samples
_____ indicates data not provided

The report contained limited information as to specific controls in place during the sampling periods; however, Dr. Corn stated that "* * * the controls for the 5 buildings were minimal O&M controls" (Ex. 162-52).

The submission of Mr. Saul, Assistant Commissioner for Occupational Safety and Health, State of Maryland included a summary of the monitoring results conducted for Maryland employees performing building maintenance activities (ex. 162-44). A total of 207 samples analyzed by PCM during May 1988 to June 1990 were analyzed. The real-time values fell into the exposure categories presented in Table VI.

Table VII. -- Asbestos Fiber Levels During Maintenance Activities
Fibers/cubic centimeter No. samples Percent of samples
<0.01 125 60.4
0.01-0.04 30 14.5
0.05-0.09 24 11.6
0.10-0.20 24 11.6
>0.20 4 1.9

During these activities, workers were required to wear personal protective equipment. In his discussion of the study results, Mr. Saul explained that the four values in excess of 0.2 f/cc resulted from: a removal in which wet methods could not be employed, wetting painted surfaces, removing and wetting metal enclosed pipe lagging, and improperly sealing of a mini-enclosure. He further concluded that these data indicate that the work practices used by these workers are generally effective during these maintenance-type asbestos activities.

In addition to the above studies showing relatively low exposures, almost all below the revised PELs, other submissions showed the potential for Class III work to exceed the PEL.

BCTD submitted studies including those by Keyes and Chesson which reported results of a series of experiments designed to determine fiber levels in asbestos-containing buildings during simulated activities (Ex.9-34 OO, PP and 7-53). They demonstrated (using transmission electron microscopic measurements) that use of dry methods in a room containing damaged ACM and visible dust and debris elevated the fiber level in air significantly, that physical activity (playing ball) within such an area increased fiber levels and that cable pulling activities also raised fiber counts.

HEI submitted an analysis of a data set provided to them by Hygienetics, Inc. which contained data on airborne asbestos fiber concentrations during various maintenance activities performed under an operations and maintenance (O&M) program in a large U.S. hospital (Ex. 162-6). During the period of study, all maintenance work in areas with ACM in the hospital required a permit issued by the Hygienetics project manager on site. The authors concluded "* * * spatial and temporal proximity to maintenance work was an important determinate of PCM fiber levels" (Ex. 1-344, p. 1.8). Jobs involving removal of ACM resulted in higher fiber levels than non-removal jobs [personal samples: mean, removal jobs = 0.166 f/cc, non-removal = 0.0897 f/cc (Ex. 1-344 p. 1.6)]. HEI concluded that these activities resulted in increased fiber levels (Ex. 1-344, p. 1.8).

OSHA has reviewed and evaluated all available information pertaining to maintenance, repair, and other asbestos-disturbing activities within buildings classified as "Class III" and has concluded that some of these activities can result in significant risk from exposure of workers. The range of activities and exposure potential encompassed by a Class III designation is wide.

The studies generally show that when protective work practices are used by trained workers, exposures are greatly reduced. Thus, OSHA is requiring various work practices and protective measures to reduce exposure to asbestos containing material (or material which is presumed to contain asbestos) and that workers must receive training in courses which include the appropriate techniques to use in handling and/or avoiding such disturbances. OSHA concludes that these are effective, feasible controls needed to reduce significant risk.

Paragraph (g)(8) sets out these requirements. Again, wet methods are required; local exhaust ventilation is required, if feasible; Where the material OSHA has found to be of high-risk, TSI and surfacing material, is drilled, cut, abraded, sanded, chipped, broken or sawed, dropcloths and isolation methods such as mini-enclosures or glove bags must be used; and respirators must be worn; and where a negative exposure assessment has not been produced, dropcloths and plastic barriers (tenting or equivalent) must be used. OSHA believes these mandatory practices will protect employees who perform Class III work from significant risk of asbestos-related effects.

Class IV Work

As defined in paragraph (b), Class IV work consists of "maintenance and custodial work" where employees contact ACM and PACM, including activities to clean up waste and debris containing ACM and PACM. Examples of such work are sweeping, mopping, dusting, cleaning, and vacuuming of asbestos containing materials such as resilient flooring, or any surface where asbestos-containing dust has accumulated; stripping and buffing of asbestos containing resilient flooring, and clean-up after Class I, II, and III work, or other asbestos construction work such as the installation of new asbestos-containing materials. Clean-up of waste and debris during a removal job, or other Class job, is Class IV work. Because in these cases the employee doing the clean-up is within the regulated area and subject to the same exposure conditions as the employees actually doing the removal, paragraph (9)(1) requires the custodial employee to be provided with the same respiratory protection as the employees performing the removal or other asbestos work.

Generally, exposures for Class IV work are lower than for other classes. Data in the record show this general exposure profile (see for example, Kominsky study, Ex. 119 I, where carpet "naturally contaminated" for year by friable, TSI and surfacing ACM was cleaned using three cleaning methods; all personal samples were below 0.022 f/ cc; using allowable methods resulted in the highest personal sample of 0.019 f/cc; see also, data in Ex. 162-52). Other data show even lower exposures for custodial work (see for example, Wickman et al, Ex. L163, where the authors conclude: "This study determined that custodians who performed routine activities in buildings which contained friable asbestos materials were not exposed to levels of airborne asbestos which approached the OSHA action level of 0.1 f/cc. The arithmetic mean value for 38 personal samples, analyzed by TEM, was 0.0009 s/cc, 8 hour TWA for structure lengths greater than 5 um" ( Id at 20). The much higher exposure data from the earlier Sawyer study, (Ex. 84-262A), showed exposure levels ranging to 4.0 f/cc for dry dusting of bookshelves under friable ACM. As noted above, at this rulemaking hearing Sawyer noted that the conditions in the building he studied were unrepresentative of other buildings in the U.S. (Tr. 2157).

OSHA believes the Wickman report is the most complete study available concerning custodial exposures. Because the study was submitted into the record after the close of the post-hearing comment periods, OSHA is not relying on it to prove the extent of exposures anticipated in most custodial work. Rather, OSHA views the Wickman study as confirming its view that Class IV activities result in reduced exposure and thus, reduced risk compared to activities of other classes. Because maintenance work involving active "disturbances" is Class III work, the "contact" with ACM which constitutes Class IV work will be either with intact materials, or in cleaning-up debris from friable material or from material which has been disturbed. The latter activities present the higher risk potential. OSHA acknowledges that evidence of asbestos disease among school custodians and maintenance workers has been submitted to this record (See e.g., references cited in SEIU's post hearing brief, Ex. 144). The Agency believes that significant exposures to custodians result from Class III work or when they clean up accumulations of friable material. Therefore, these revisions contain several requirements aimed at reducing custodial exposures when cleaning up asbestos debris and waste material.

OSHA believes that the work practices and precautions prescribed in these regulations will virtually eliminate significant health risks for custodial workers, and will cure any confusion about which protections and which standards will apply to custodial worker (see submission of SEIU, Ex. 144).

Custodial work is covered in all three standards. Housekeeping provisions in the general industry standard, paragraph (k), cover custodians in public and commercial buildings, in manufacturing and other industrial facilities, where construction activity is not taking place. To avoid confusion, and to cover clean-up, and other housekeeping on construction sites, which properly is covered under the construction standard, similar "housekeeping" provisions are included in the construction and shipyard standards as well (Paragraph (1). These housekeeping provisions are discussed separately. The specific provisions in paragraph (g), relating to Class IV work in the construction standard relate to construction work only, and are not necessarily limited to housekeeping. Like all other construction work, competent person supervision of Class IV work is required, exposure assessments of clean-up of waste and debris, and use of HEPA filtered vacuums, in paragraph (g)(1) apply.

Particular requirements were adopted in response to concerns of some participants. These are paragraph (g)(9) which requires specific awareness training for Class IV workers. Under the 1986 standard, training was not required unless employees were exposed above the action level, then 0.1 f/cc. Two labor organizations representing employees who perform Class IV work, SEIU and AFSCME, and other participants, (see e.g., Ex. 141, 144), noted that custodial workers needed training, separate from other building service workers, such as maintenance workers (Ex. 141 at 49), generally referred to as "awareness training." The record shows the lack of awareness that material contained asbestos contributed to asbestosis (Tr. 959 ff). Paragraph (g)(9) of the construction and shipyard standards requires that Class IV asbestos jobs be performed by employees trained according to the awareness training set out in the training section, (k)(8). The general industry standard, also requires that employees who work in areas where ACM or PACM is present, also be so trained, in paragraph (j).

In addition, paragraph (g) requires employees cleaning up waste and debris in a regulated area where respirators are required to be worn to also wear respirators. This restatement of the provision in paragraph (e)(4) relating to regulated areas emphasizes that clean-up workers in large-scale jobs must wear respirators, even though the actual removal is completed. Paragraph (g)(g)(iv) offers significant protection to custodians. As pointed out by participants, custodians have swept up "insulation debris which had fallen to the floor because it was so badly deteriorated * * * with no knowledge or concern about asbestos hazards * * *" (see testimony of Ervin Arp at Tr. 962-969). This new provision requires that "(e)mployees cleaning up waste and debris in an area where friable TSI and surfacing ACM is accessible, shall assume that such waste and debris contains high-risk ACM. Since paragraph (k) requires that such ACM and PACM be visibly labeled, OSHA believes that custodial workers will be spared the consequences of being required to clean-up unidentified materials, which in fact contain asbestos.

Various participants asked OSHA to require an employer to adopt and operations and management (O&M) program to protect custodial and maintenance workers. The Agency notes that the 1986 standard contained, in non-mandatory Appendix G, such a program, which listed precautionary actions which the Agency recommended.

OSHA has not adopted an explicit O&M program requirement in these standards. Rather, the Agency has adopted enforceable provisions which cover the major elements of the previous non-mandatory program in the appendix, and of various programs suggested by participants in this rulemaking. For example, the new requirement that maintenance and custodial work be the subject of exposure assessments, [see paragraph (f)(2)], requires the competent person to evaluate operations which may expose employees to asbestos, in order to minimize exposure. The requirement is "operation" based; rather than, as in an O&M program, status-based. However, any active disturbance constitutes an operation. Although each "operation" must be covered by an exposure assessment, operations can be grouped. Cleaning up debris in an area containing deteriorating ACM on a daily basis, need not be evaluated each day. An assessment of such activity can be made on a general basis, covering procedures for wet sweeping and vacuuming, disposal, and instructions to detect deterioration of material which contributes to the debris. Additionally, labeling of ACM and PACM usually considered part of an O&M program, is separately required, as is training of custodial workers. Specific jobs may require specific instructions; the breadth of some are indicated by O&M documents generated by the EPA "Green Book" (Ex. 1-183, EPA 20T-2003, July 1990 and NIBS Ex. 1-371). OSHA believes that competent person supervision of activities under this standard will provide appropriate work practices to be followed for relatively small, less hazardous exposure situations. The Agency is requiring however, in the training provisions, that when Class III and IV workers are trained, that the contents of the EPA or state approved courses for such workers, as the relate to the work to be performed, be part of the required training material [paragraph (k)(v)(D)].

The issue of passive exposure, that is where active contact or disturbance of ACM is not a contributing factor to asbestos fiber release, is covered by the various notification and identification provisions in the standard which will allow employees to identify asbestos-containing material. These are discussed later in this preamble.

In OSHA's expert view, these provisions constitute major components of operations and maintenance programs recommended; are aimed at the more significant sources of exposure for custodial workers, and most importantly, are enforceable. For all these reasons, OSHA believes an explicit requirement for an O&M program, such as suggested by AFSCME (Ex. 141 at 36), would add little benefit to employee health (see e.g., Tr.3500).

In each standard, OSHA is requiring specific work practices and a choice of engineering control however, OSHA is aware that some asbestos control systems may be patented. OSHA has not considered the existence of patents or their validity in evaluating the need for those controls. OSHA believes that all employers will have a variety of controls available to them and that new types could be developed.

(8) Respiratory Protection

Paragraph (g) General Industry

The 1986 general industry standard required respirator use where engineering and work practice controls are being installed, in emergencies, and to reduce exposures to or below the PELs where feasible engineering controls and work practices could not achieve these reductions. Additionally, certain operations i.e., cutting in plants, were shown to have greater difficulties in achieving low exposures without respirator use. OSHA therefore allowed routine respirator use in those segments to reach the PELS, rather than, as in other general industry segments, only where the employer shows that feasible engineering and work practice controls cannot achieve compliance with the PELs. OSHA now believes that engineering and work practices in the few remaining production sectors can achieve lower levels than predicted in 1986, in part because of the mandatory work practices now included in the methods of compliance section. Therefore, allowing respirator use at higher measured exposures for a few operations should not result in less protection for those employees since their ambient exposure levels are expected to be reduced.

Paragraph (h) Construction Standard and Shipyard Employment Standard. The respirator provisions in the construction and shipyard employment standards are changed in several respects. First, in addition to the conditions listed in the 1986 standards, where exposures exceed the PELs, required respirator use now is triggered by kinds of activities even where the PELs are not exceeded. These are: Class I work, Class II work where the ACM is not removed substantially intact; all Class II and III work where the employer cannot produce a negative exposure assessment; and all Class IV work carried out in areas where respirators are required to be worn. OSHA has based these decisions on the demonstrated variability during asbestos work, and on the need to protect workers who are disturbing asbestos-containing material with the greatest potential for significant fiber release. In addition, monitoring results for many jobs are not available in a timely fashion. By requiring routine respirator use in jobs which OSHA finds are likely to result in hazardous airborne asbestos levels, such as floor tile removal, where most tiles are broken, OSHA is providing reasonable supplemental protection to employees when certainty concerning exposure levels is not possible.

The kind of respirators required for these "conditions of use" are set out in paragraphs (h)(iv) and (v). In one situation, as explained below, Class I removals where excessive levels are predicted, "supplied air respirators operated in the positive pressure mode" are required, because these jobs have the highest exposure potential, due to their size, duration and the kinds of material involved. Other jobs where higher than usual exposures may occur include, where employees are inexperienced, where TSI and surfacing ACM is disturbed, and where other ACM is broken up during removal. Paragraph (h)(1) states the requirement for supplemental respirator use for these activities as well. These additional respirator requirements conform to OSHA's findings on this record, of the specific conditions which contribute to and are predictive of, higher exposures.

As discussed more fully in the classification section, the data submitted to the record show that in almost all cases of removals and disturbances of non-high-risk ACM, exposure levels are well below the protection factor limits for negative-pressure half-mask respirators, the type required for certain kinds of Class II and III work.

BCTD has recommended that OSHA require the use of "the most effective respirator that is feasible under the circumstances" and further that OSHA require "supplied air respirators which are tight fitting and in a pressure demand mode with either auxiliary SCBA or a HEPA egress cartridge * * * except in limited circumstances which include lack of feasibility because of the configuration of the work environment or an uncorrectable safety hazard" (Ex. 143 at 65-69). BCTD does recognize safety hazards due to the tripping hazard of air lines to which SARs are attached and define certain activities in which PAPRs may be used instead. (Ex. 143 at 71). BCTD also contended that the protection factors used by OSHA to assign respirator classes are contrary to record evidence.

The Court found that OSHA's judgment about supplied air respirators was properly within its discretion. It expressed concern that OSHA's respirator requirements did appear to require only that the combined effect of engineering and work practice controls and respirators limit exposure only as low as the PEL where significant risk remained (838 F.2d at 1274).

OSHA responded to these issues in a Federal Register publication of 5 February 1990 (55 FR 3727), in which the Agency reaffirmed its position concerning effectiveness levels of respirators, pointed out flaws in studies BCTD used to conclude that protection factors are inadequate, and noted that OSHA is revising and updating its general respirator standard. OSHA also noted that implementation of the entire respirator program would result in exposures below the PEL. That was OSHA's final statement of position on these issues and it was not judicially challenged.

In evaluating the respiratory protection needs dictated by the new system of ranking for asbestos operations by "class," OSHA has concluded that there are circumstances in which the highest level of respiratory protection must be used. These are Class I jobs for which a negative exposure assessment (i.e. exposures will be less than the PEL) has not been made. Inexperienced workers removing large amounts of TSI or surfacing ACM are at the high end of the risk spectrum and must have additional protection afforded by the supplied air respirator. OSHA notes that joint EPA-NIOSH recommendations would require a supplied air respirator in even more extensive circumstances, i.e., all "abatement" work and maintenance and some repair work (EPA/NIOSH Guide, referenced at Ex. 143, p. 69). The Agency"s decision balances the acknowledge potential safety hazards of supplied air respirators with the need for more protection in the most risky asbestos jobs. The Court of Appeals has agreed that such judgments are properly within the discretion of the Agency (858 F2d at 1274). In situations where the competent person makes a determination that exposures in Class I jobs will be less than the PELs, the standard requires that a half-mask air purifying, non-disposable respirator equipped with a high efficiency filter must be used. There are two reasons for this requirement: exposures less than the PEL have been determined to result in significant risk, the record shows that Class I work may result in substantial exposures even when good conditions exist, and the variability usually results in some high exposures. However, although all classes of asbestos work are potentially risky, OSHA has used discretion, and has limited the supplied air respirator provision to the highest risk situations, Class I work where it cannot be predicted that exposures will not exceed the PEL. This approach does not leave workers doing other classes of work unprotected. The respirator selection Table D-4, applies to all situations other than Class I work. As the worker(s) gain experience in the use of control methodology, and data accrues documenting low fiber levels, use of less protective respirators may be allowed.

Furthermore, OSHA has based this conclusion on the demonstrated variability of exposures in the construction industry (Ex. 143, p. 63, CONSAD report p. 2.18, Tr. 2156, 2157, Tr. 4571, Ex. 7-57). The contractor Consad reported "while many of the construction jobs monitored did not produce exposure levels above the proposed PEL of 0. 1 f/cc, these data also provide continued evidence that exposure levels can be highly variable in construction work and can exceed the proposed PEL * * * for many of the construction activities examined here" (Ex. 8, 2.18-20).

Shipyard Employment Standard

Paragraph (h). SESAC has recommended the deletion of the qualitative fit test from the shipyard employment asbestos standard. Their rationale is as follows:

The Committee has determined that advances in quantitative fit testing instrumentation have made this procedure accessible to shipyards conducting asbestos operations at a cost which is not overly burdensome ($5,000-6,000 at the low end). Because quantitative fit testing provides a better evaluation of fit among respirators than qualitative methods, and does not rely on subjective determination by the employees, qualitative fit testing methods have been deleted as acceptable alternatives * * * (Ex. 7-77).

They further recommended, based on the recent developments in technology that the use of test chambers, and the requirement for use of aerosols be deleted. They also offered an additional definition: "challenge agent" means the air contaminant, or parameter, which is measured for comparison inside and outside of the respirator facepiece." These are reasonable suggestions, but as they have general application outside shipyards, OSHA indicated this in its notice of February 5, 1990 in its partial response to the Court. The Agency is "still planning to revise and update its general respiratory standard, and believes that continuing to enforce the current asbestos respirator requirements during this interim period will not expose employees to unnecessary risk" (55 FR 3728, February 5, 1990). Therefore, OSHA will not delete the qualitative fit test from the asbestos standard(s), but will consider the issue in the context of the general respiratory standard.

SESAC objected to the requirement that a powered, air-purifying respirator be supplied in lieu of a negative-pressure respirator when the employee chooses it and when it will provide adequate protection. They felt that the employer should be allowed to provide an airline respirator or powered air-purifying respirator. They reasoned that most employers already will have airline respirators in stock and will not need to purchase or maintain any other type of respirator. In evaluating similar comments in the rulemaking for the 1986 revised asbestos rule, OSHA stated:

OSHA agrees that positive-pressure supplied-air respirators provide a greater level of protection than do half-mask negative-pressure respirators. OSHA believes that employers should have the flexibility to use any of the available respirators that provide sufficient protection to reduce the exposures to levels below the PEL. Furthermore, the safety problems associated with the use of supplied-air respirators cannot be ignored. OSHA believes that respirators should be selected that both provide adequate protection from exposure to airborne asbestos fibers and minimize the risk of accident and injury potentially caused by the use of cumbersome supplied-air respirators (51 FR p. 22719, June 20, 1986, p. 22719).

After that rulemaking, BCTD challenged OSHA's refusal to make air supplied respirators mandatory. The Court accepted OSHA's explanation -- that supplied-air respirators had hazards of its own, and stated "this sort of judgment * * * (is) within OSHA's discretion in the absence of evidence supporting the view that the incremental asbestos safety gains plainly exceed the incremental non-asbestos hazards" (838 F.2d at 1274). OSHA reiterated these reasons in its January 28, 1990 response to the Court's remand.

As discussed above, OSHA has determined on this record that supplied air respirators are required for Class I work where a negative exposure assessment is not forthcoming, but not for other Class I work. Therefore, shipyard employees doing the most hazardous work must wear this most protective respirator as well.

(9) Protective Clothing

Paragraph (h) General Industry. OSHA is making no changes in the protective clothing provisions for general industry. Paragraph (i) Construction and Shipyard Standards.

There are several protective clothing issues in this rulemaking. The first issue involves the impact of the Class system on the personal protective clothing provisions. The existing standard requires that protective clothing be provided and worn when exposures exceed the PEL. The revised standards maintain this requirement. In addition, the revised standards require the use of personal protective clothing when Class I work is performed and when Class III work involving TSI and surfacing ACM is performed in the absence of a negative exposure assessment. OSHA believes that this change brings the standard in line with OSHA's 1986 intentions wherein the Agency believed that removal of thermal insulation and surfacing materials would result in exposures that exceed the PEL. This rulemaking record shows that some employers have developed control strategies that can reduce exposures below the PELs, for most of the time. However, as previously discussed, work with high-risk materials has substantial potential for over-exposure. Furthermore, studies have documented that in the past workers have brought asbestos contaminated clothing home with them and thereby caused exposure and asbestos-related disease among family members. OSHA believes that this standard must prevent such conditions, and the nature of Class I work and Class III work with high risk materials merits special consideration. Nearly all rulemaking participants agree on this point.

OSHA notes however, that the judgment to require protective clothing for asbestos work is a subjective one, to some extent, requiring judgment on the part of the competent person. The hazard from asbestos is associated with inhalation of fibers that are in the air, not from asbestos that comes in contact with the skin, like some other chemical that OSHA has regulated (such as methylenedianiline and benzene), which are absorbed through the skin and are systemic toxins. Asbestos fibers that are on clothing can become airborne, so OSHA continues to believe that situations where airborne fiber levels are high are also those which are likely to contaminate clothing. Therefore, the regulation continues the requirement for protective clothing and its proper disposal/cleaning. OSHA does not believe, however, that protective clothing is required for every operation involving asbestos.

In the 1986 standards OSHA did not require that protective clothing be impermeable; in fact, OSHA responded to concerns that disposable clothing which was impermeable not be permitted because it was claimed to contribute to heat stress (see discussion at 51 FR 22722). Although the issue was not remanded to OSHA by the Court, several participants in the current rulemaking focused comment on the issue of whether OSHA should require work clothing during asbestos work be impermeable to asbestos fibers in each of its asbestos standards. Most of those who addressed the issue expressed support for having such a requirement (Exs. 7-10, 7-67, 7-69, 7-138, 7-192, 7-195, 1-242, Tr. 1122, 1142, 1950, 3003 and 3156). It should also be noted that several of these commenters were manufacturers of such fabric or clothing. They also encouraged OSHA to set a requirement that all garments meet the requirements of the ANSI standard 101-1985.

Charles Salzenberg of Dupont presented a study which was performed at their behest by A.D. Little which indicated that neither shampooing the hair nor showering following simulated asbestos exposure completely removed fibers from hair or skin (Ex. 76) to support their request for an impermeable clothing requirement. In response to questioning about heat stress, he stated that:

We've had projects for years on improving the breathability of Tyvek and in fact we have some material that exhibits improved breathability and the problem you always get when you get more breathability, you get more asbestos. There doesn't seem * * * a way to have a perfect filter that keeps out all fibrous material but lets a lot of air through * * * (Tr. 3444).

OSHA continues to believe that heat stress is also a concern in use of protective clothing made of impervious fabric. It should again be noted that the route of exposure of asbestos fibers which creates a health hazard is inhalation, not skin absorption. The Agency reiterates its belief that non-disposable work clothes provide sufficient protection provided they are properly cleaned after work and laundered. The Agency agrees that disposable fiber-impermeable clothing can be safely worn if "employers * * * use appropriate work-rest regimens and provide heat stress monitoring * * *" (51 FR 22722). However, OSHA does not believe that totally impermeable clothing is a necessary requirement for asbestos work.

(10) Hygiene Facilities and Practices

Paragraph (j) Construction and Shipyard Employment Standards.

OSHA is changing the decontamination requirements in minor details to correspond to its new system of categorizing asbestos work according to its potential risk. The primary requirement that asbestos abatement workers be decontaminated following their work using a 3-part system -- an equipment room, a shower room, and a clean room, is retained. Thus, most workers performing Class I work, removing TSI or surfacing ACM or PACM, as before, must use a shower adjacent to and connected with the work area.

With the introduction of new provisions identifying 4 classes of asbestos work, it is necessary that OSHA modify its requirement for hygiene facilities and practices to reflect these changes. OSHA continues in its belief that the requirements must be proportional to the magnitude and likelihood of asbestos exposure. Therefore the most hazardous asbestos operations -- those involving removal of more than threshold amounts of thermal system insulation or sprayed-on or troweled-on surfacing materials must employ a decontamination room adjacent to the regulated area (most often, a negative-pressure enclosure) consisting of an equipment room, shower room, and clean room in series through which workers must enter and exit the work area, as required in the 1986 standard.

For Class I asbestos work, OSHA has further determined, based on its consideration of the rulemaking record, that there are 3 exceptions to the requirement that the shower facility be located immediately contiguous to the work area. These include, outdoor work (See Ex. 7-21, 7-99, 7-145), shipboard work (Ex. 7-77 and see discussion below), and situations where the employer shows such an arrangement is infeasible. OSHA will again allow in these limited circumstances the workers to enter the equipment room, remove contamination from their worksuits using a portable HEPA vacuum or change to a clean non-contaminated workclothing, and then proceed to the non-contiguous shower area. Outdoor work affected by this requirement will occur mainly in industrial facilities such as refineries and electrical power plants when specified work practices are employed and following outdoor asbestos work.

OSHA intends that HEPA-vacuuming procedures be performed carefully and completely remove any visible ACM/PACM from the surface of the worker's work suit, including foot and head coverings, skin, hair and any material adhering to the respirator.

Also for Class I work involving less than 10 square feet or 25 linear feet of TSI or surfacing ACM (the thresholds referenced above), during which exposures are unlikely to exceed the PELs for which there is a negative exposure assessment, OSHA is allowing less burdensome decontamination procedures which it believes are compatible with the scheme to classify asbestos work according to risk potential. In these operation, an equipment room or area must be set up adjacent to the work area for decontamination use. The floor of the area/room must be covered with an impermeable (e.g., plastic) dropcloth and be large enough to accommodate equipment cleaning and removal of PPE without spread of fibers beyond the area. The worker must HEPA vacuum workclothing, hair, head covering as described above and dispose of clothing and waste properly. Thus, only if the employer shows that for these smaller dimension jobs that the PEL is unlikely to be exceed may the decontamination procedure be abbreviated.

For asbestos operations which are Class II and III which are likely to exceed the PELs and for which a negative exposure assessment is not produced, showering is required, but may be performed in a facility which is non-contiguous to the work area. Use of dropcloths, HEPA vacuuming of workclothing and surfaces as above or the donning of clean workclothing prior to moving to a non-contiguous shower is required.

Following those Class II, III and IV jobs which the employer demonstrates are unlikely to exceed the PELs and for which a negative exposure assessment has been produced, the worker must HEPA vacuum his clothing on an impermeable dropcloth and perform other clean-up on the dropcloth avoiding the spread of any contamination. However, showering is not required.

OSHA is also concerned that workers performing clean-up (Class IV work) following larger abatement work receive appropriate decontamination. Therefore, employees who perform Class IV work in a regulated area must comply with the hygiene practice which the higher classification of work being performed in the regulated area requires.

Shipyard Employment Standards; Paragraph (i)

In other comments the Shipyards Employment Standards Advisory Committee objected to the requirement in the 1986 standard that showers be located contiguous to the work area. They said that this was not a part of the general industry standard and that they wished to continue to provide showers in fixed facilities on shore; that although contiguous showers may not be technologically infeasible, it was impractical. They further stated that change rooms required under the general industry asbestos standard cannot be provided on ships and that the worker must be allowed to remove contaminated clothing in an equipment room as in the construction standard (Ex. 7-77).

The Committee suggested several specific steps to the decontamination process required of workers following work in a shipboard asbestos activity. According to these recommendations, the employer shall ensure that employees who work within regulated area exit as follows:

Remove asbestos from their protective clothing using a HEPA vacuum as they move into the equipment room;

Enter the equipment room and remove their decontaminated outer layer of protective clothing and place them in the receptacles provided for that purpose;

Enter the decontamination room and perform personal HEPA vacuuming;

Remove respirator after exiting decontamination room;

Wash their face and hands prior to eating or drinking;

If they are not going to make another entry into the regulated area that day, proceed to the shower area and change room; and, Don street clothing (Ex. 7-77).

OSHA believes these are reasonable suggestions. The final standard permits this approach based on the flexibility permitted by the language. Those who shower at remote facilities are required to decontaminate their protective clothing prior to proceeding to the remote showers. The Committee also recommended that, for the sake of modesty, the worker must be allowed to continue to wear the underwear which he had worn under his protective clothing during the process of decontaminating his clothing -- removing them when entering the shower. The 1986 standards are silent on this point and it seems reasonable that persons would be allowed to continue to wear his/her underwear during HEPA vacuuming and removal of protective clothing.

The committee pointed out that the general industry standard requires lunchrooms, while the construction standard requires lunch areas, and that areas were sufficient. OSHA agrees that it is unnecessary to build lunchrooms in shipyard facilities, so long as the area provided for food consumption is not so close to the work area that asbestos contamination is likely. In that case, areas are insufficient and an enclosed room must be provided which is free of contamination.

(11) Communication of Hazards to Employees

Paragraph (j) General Industry. Paragraph (k) Construction and Shipyard Employment Standards.

The "communication of hazards" provisions of the standards contain many revisions. The Court in 1988 had remanded two information transfer issues for OSHA's reconsideration. These were to extend the reporting and information transfer requirements and to require construction employers to notify OSHA of asbestos work. As discussed earlier, OSHA has decided not to require general pre-job notification to the Agency. However, the Agency has expanded required notifications among owners, employers and employees. Basically, the general industry standard has been upgraded to the more extensive notification requirements of the construction standard and the shipyard employment standards. Consequently this preamble section discusses the issues together. In the shipyard standard the "building owner" may be a vessel owner or a building owner. OSHA notes that in shipyards vessels undergoing repair may be owned by foreign entities, as well as by entities subject to the Act's jurisdiction. When a foreign-owned vessel is repaired in an American shipyard, the employer (either the shipyard or an outside contractor) must either treat materials defined as PACM as asbestos-containing or sample the suspect material and analyze it to determine whether or not it contains asbestos.

An overview of these revisions follows. The construction and shipyard standards now require that employers who discover the presence of material which is ACM or is presumed ACM (PACM) on the worksite, must notify the project or building owner. On worksites having multi-employers, the person who discovers the material also is to notify the other employers. An employer on a multi-employer worksite who is planning Class I or Class II asbestos work is to inform all the other employers on the site of the presence of ACM to which employees of those employers might reasonably be expected to be exposed. They are to be informed of the location and quantity of these materials and the measures to be taken to protect them from exposure.

The 1986 construction standard required employers to notify other employers on multi-employer worksites of the existence and location of asbestos work, but was silent on the notification role of building owners. OSHA was concerned that building owners were "outside the domain of the OSH Act." As noted above, this is a specific issue remanded for reconsideration by the Court of Appeals. Now, upon reconsideration, OSHA believes that it has authority to require building owners [as defined in paragraph (b)] who are statutory employers, to take necessary and appropriate action to protect employees other than their own. In the 1990 proposal OSHA pointed to other standards in which it has required building owners and other employers who are not the direct employers of the employees exposed to particular hazards, to warn of defects, take remedial action, or provide information to the directly employing employer. It cited the Hazard Communication Standard's requirement that manufacturers provide information to downstream employers (29 CFR 1910.1200) and the Powered Platform standard which requires the building owner to assure the contract employer that the building and equipment conform to specified design criteria as examples (29 CFR 1910.66(c).) OSHA believes that the building or project owner is the best and often the only source of information concerning the location of asbestos installed in structures; therefore, OSHA is requiring the owner to receive, maintain, and communicate knowledge of the location and amount of ACM or PACM to employers of employees who may be exposed. OSHA acknowledges that in shipyards, foreign vessel owners are not "statutory employers" and thus, are not covered by these standards. In such cases, the employer performing the "refit" must either presume that TSI and surfacing material are asbestos-containing, or have the material tested. When turn-around time must be minimized, the case in many overhauls, OSHA expects that the jobs will be performed in conformity with this standard without testing.

The final rule provides a comprehensive notification scheme for affected parties -- building owners, contract employers and employees, which will assure that information concerning the presence, location, and quantity of ACM or PACM in buildings is communicated in a timely manner to protect employees who work with or in the vicinity of such materials. Before Class I, II, or III work is initiated, building and/ or project owners must notify their own employees and employers who are bidding on such work, of the quantity and location of ACM and PACM present in such areas. Owners also must notify their own employees who work in or adjacent to such jobs.

Employers, who are not owners, planning any such covered activity must notify the owner of the location and quantity of ACM and PACM known or later discovered. The building owner must keep records of all information received through this notification scheme, or through other means, which relates to the presence, location and quantity of ACM and PACM in the owner's building/project or vessel and transfer all such information to successive owners. OSHA reaffirms its finding of the 1986 standard that an employee's presence in the workplace places him at increased risk from asbestos exposure regardless of whether he/she is actually working with asbestos or is just in the vicinity of such material.

OSHA has defined "building owner" to include these lessees who control the management and recordkeeping functions of a building / facility/vessel. It is not OSHA's intention to exempt the owner from notification requirements by allowing a lessee to comply. Rather when the owner has transferred the management of the building to a long-term lessee, that lessee is the more appropriate party to receive, transmit, and retain information about in-place asbestos. When a lease has expired, any records in the lessee's possession must be transferred to the owner or the subsequent lessee exercising similar managerial authority. The expanded notification provisions also require that on multi-employer worksites, any employer planning to perform work which will be in a regulated area, before starting, must notify the building owner of the location of the ACM and the protective measures taken; upon discovering unexpected ACM, they must provide similar notification; and, upon work completion they must provide to the owner a written record of the remaining ACM at the site.

OSHA has included a provision that within 10 days of the completion of Class I or II asbestos work, the employer of the employees who performed the work shall inform the owner and employers of employees who will be working in the area of the current location and quantity of PACM and/or ACM remaining in the former regulated area and shall also inform him/her of the final monitoring results taken in that operation. OSHA has determined that the employer of employees reoccupying the area must have this information in order to provide the appropriate protection to his/her workers.

To provide effective notification in Class III asbestos operations, OSHA is building upon its earlier requirement to post warning signs in regulated areas. Now since all Class III work must be conducted in a regulated area all maintenance-type operations will be posted with signs, which state the fact that asbestos exposing activities are present. OSHA considers site posting to be a particularly effective means to alert employees of hazardous areas where relatively short-term repair and maintenance activities are taking place. OSHA believes that site posting will adequately notify potentially affected employees who are not working on the operation, but are working within the area or adjacent to it.

Identification of Asbestos-containing Materials in Buildings and Facilities

In addition to the "notification" issues just discussed, OSHA addresses a related widespread concern expressed by participants in this rulemaking: how to ensure that workers in buildings and facilities with previously installed asbestos containing products, are not exposed to asbestos fibers merely because they have no knowledge of where such products were installed. OSHA has found that such workers, primarily maintenance workers and custodians, but also contract workers such as plumbers, carpenters and sheet metal workers and workers in industrial facilities have shown historic disease patterns which in large part resulted from exposure to previously installed asbestos. (see discussions elsewhere in this preamble of data submitted by BCTD, AFSCME, SEIU and others). In its 1990 proposal OSHA raised the issue of how to identify previously installed asbestos and asked for comments and recommendations (55 FR 29730). OSHA opened the record for supplemental comments in November 1992, in a notice which also set out OSHA's preliminary views on how to effectively protect workers from unknowing exposure to previously installed ACM (57 FR 49657). There, OSHA proposed to require employers to presumptively identify certain widely prevalent and more risky materials. These are thermal system insulation, and sprayed-on and troweled-on surfacing materials, in buildings built between 1920 and 1980. These materials were to be termed "presumed asbestos containing materials" (PACM) and were to be treated as asbestos containing for all purposes of the standard. OSHA would have allowed building owners and employers to rebut these presumptions using building records and/or bulk sampling.

The final provisions which are included in all three standards, like OSHA's 1992 approach, require building owners and employers to presume that thermal system insulation (TSI) and sprayed-on and troweled-on surfacing materials contain asbestos, unless rebutted pursuant to the criteria in the standard. Additionally, OSHA is requiring in its mandatory work practices for flooring material containing asbestos, that employers assume that resilient flooring material consisting of vinyl sheeting, and vinyl and asphalt containing tile installed before 1980 also be presumed to contain asbestos (see discussion in the "Methods of Compliance" section). Unlike the proposal, buildings constructed before 1920 are not excluded from these requirements. Also rebuttal criteria have been changed. Unlike the approach OSHA suggested in the November, 1992 notice, building records may not be relied upon to rebut the presumption of asbestos containing material and more detailed instructions are supplied for the inspection process.

OSHA believes that these provisions will protect employees in buildings and facilities from the consequences of unknowing significant exposure to asbestos in the most cost-effective manner.

Participants supported OSHA's "presumptive" approach to identifying asbestos-containing material; in particular, designating only TSI and surfacing ACM for presumptive treatment (see e.g., utility companies such as Southern Cal. Edison, Ex. 162-4; Con Edison, Ex. 162-54; Duke Power, Ex. 162-57; property management companies and associations, e.g., JMB Properties, Ex. 162-29; trade associations, e.g., O.R.C., Ex. 162-12; International Council of Shopping Centers, Ex. 162-58).

As stated in the November 1992, OSHA continues to believe that the major advantage of such a regulatory approach is that the materials and buildings/facilities with the greatest risk potential would be automatically targeted for mandatory communication and control procedures, and possible testing. Focusing on high-risk building/ facility situations avoids the dilution of resources and attention which might result from requiring broader inspections. Other building/ facility areas and material would not be exempt from the standard's control requirements; however, they would not be presumptively considered to contain asbestos. If a building owner or employer has actual knowledge of the asbestos content of materials, they must comply with the protective provisions in the standard. Similarly if there is good cause to know that material is asbestos containing the employer and/or building owner is deemed to know that fact. The current enforcement rules governing "employer knowledge" would be applied in a contested case to determine the application of the asbestos standard to other materials or building/facility areas which the employer claims he did not know contained asbestos.

OSHA believes that this presumptive approach allows building/ facility owners whose buildings/facilities contain PACM and other employers of employees potentially exposed to PACM flexibility to choose the most cost-effective way to protect employees. They may treat the material as if it contains asbestos and provide appropriate required training to the custodial staff; test the material and rebut the presumptions; or combine strategies.

OSHA considered a number of approaches to insure that workers do not become exposed to asbestos unknowingly. As noted in the 1992 notice, one option was clarifying in the preamble to the final rule the current enforcement policy that a prudent building/facility owner or other employer exercising "due diligence" is expected to identify certain asbestos-containing materials in his/her building/facility before disturbing them. After reviewing the record, OSHA believes its presumption approach is more protective. "Due diligence," is, in part, a legal defense, invoked by and in order to shelter employers against OSHA citation. Thus in the past, employers who were wrongly informed by building owners about the asbestos content of thermal system insulation successfully argued in some cases that they had exercised "due diligence." OSHA believes that the protection of employees must not depend on the good faith of their employers whose information sources may be defective. By requiring that TSI and troweled- and sprayed-on surfacing material be handled as if they contain asbestos, employees will be protected from the consequences of their employers relying on erroneous information about the most risky asbestos materials. Of course, "due diligence" would also require employers to investigate whether other building material about which there was information suggesting asbestos content, was in fact asbestos-containing. A building owner/employer, for other materials, also may presume they are asbestos-containing, label and treat work with them as asbestos work, without testing the material for asbestos content.

Another option OSHA considered was requiring a comprehensive AHERA-type (EPA's schools rule) building/facility inspection. AHERA (Asbestos Hazard Emergency Response Act, 40 CFR 735) requires that all school buildings be visually inspected for asbestos-containing building materials (ACBM) by an EPA-accredited inspector and that inventory of the locations of these materials be maintained. Under AHERA, school maintenance and custodial staff who may encounter ACBM in the course of their work receive at least 2 hours of awareness training, and for staff who conduct activities which disturb ACBM, an additional 14.

Requiring comprehensive building and facility inspections like EPA does under AHERA was recommended by participants presenting labor interests (e.g., AFSCME Ex. 162-11; SEIU, 162-28; AFL-CIO, Ex. 162-36; BCTD, Ex. 162-42): by engineering, management and asbestos abatement firms, (e.g., Abatement Systems, Inc. Ex. 162-8, California Association of Asbestos Professionals, Ex. 162-27); and by representatives of state health agencies (e.g., North Carolina Department of Health and Natural Resources, Ex. 162-46; N.Y.C. Department of Environmental Protection, Ex. 162-47).

Although there was substantial support for a comprehensive inspection requirement, OSHA believes that the regulatory approach in these final standards will achieve equivalent or superior protection to exposed workers at much reduced cost.

The reasons are as follows. A comprehensive wall-to-wall inspection requirement is found to be unnecessary to protect employees against risks of exposure from asbestos-containing building material of which they are unaware. Such an inspection requirement would be very costly, may be overly broad, the results may not be correct or timely, would not necessarily focus on potential sources of asbestos exposure which present significant risks to employees, and its great expense may divert resources from active protection of workers who actually disturb asbestos. First, OSHA does not believe that protecting employees in buildings from significant asbestos exposure requires that all suspect materials in buildings first be identified. Although all asbestos-containing materials may release fibers when their matrices are disturbed, certain materials are known to be more easily damaged or to suffer more deterioration, and thus cause higher airborne fiber levels than others. As discussed in the November 1992 notice, OSHA determined that thermal system insulation (TSI) and sprayed on and troweled on surfacing materials are such materials. They are potentially more friable, are much more prevalent, are more accessible and are the subject of more maintenance and repair activities than are other asbestos containing materials. They are widely prevalent. A 1984 EPA study limited to residential, commercial and public buildings nationally, found about three quarters of such buildings had asbestos- containing TSI, and over one quarter of the buildings contained sprayed-on or troweled-on asbestos containing surfacing material (see also studies cited in the HEI Report, Ex. 1-344, p. 4-6 to 4-10). The materials are usually accessible. Surfacing material was applied for decorative and acoustical purposes early on, and was later applied as insulation coating to protect structural steel during fires. The HEI Report in summarizing studies conducted in New York, California, and Philadelphia stated that "(i)mportant findings from these studies include the frequent use of friable surfacing in multi-storied buildings and the high proportion of damage to thermal systems insulation, most of which is accessible only to maintenance personnel (HEI Report, Ex. 1-344, p. 4-8 to 10). The accessibility of thermal system insulation is not limited to employees who directly disturb it to repair or replace the piping and infrastructure it covers. As noted by a participant: in industrial settings there are many sources of fiber release including vibration (people often walk on pipes), exposure to the elements, fans and processes, leaks, process leaks, and releases through joints in metal cladding (Ex. 12-7, Respirable Fibers Management Consultancy, Inc.).

The data submitted to OSHA indicate that these two materials have high exposure potential. For example, the potential of surfacing material to become friable and result in sizable exposures was shown by the Yale Architecture School data, which involved exposure to a "fully exposed acoustical material," a "Spanish moss type material" of low density and high friability (Tr. 2168). Dr. Sawyer, whose study showed very high exposures to custodial employees from exposure to dust and debris from this material, noted that its use in the building was unrepresentative, and that the material usually is "used primarily as a fireproofing material on structural steel that was concealed." (Id). Work in ceiling spaces containing sprayed asbestos show elevated exposure levels (see e.g., studies discussed in HEI, Ex. 1-344, p. 4-74). Data showing high exposure levels from TSI are ample and are discussed in detail in the preamble discussion on methods of compliance.

The data in this record showing exposures to other kinds of asbestos containing material such as gaskets, wallboard, roofing and siding materials show that generally, exposures to these products under comparable controls are lower than those released by the materials designated by OSHA as "high hazard" and for which the presumption applies. The "high-hazard" materials are much more prevalent in buildings and facilities, disturbances of them are more common. Therefore OSHA believes that a targeted approach to presuming the presence of high hazard previously installed asbestos containing materials in buildings which are likely to contain them will provide equivalent protection to potentially exposed employees than a requirement to inspect all buildings and facilities for all asbestos containing materials. Some building owners will continue to conduct comprehensive surveys, others, when cost is an issue, will rely on presumptions to protect employees from potential exposure to high-risk ACM, TSI and surfacing materials.

In addition, even an up-front inspection rule must be targeted to be productive. Since not all facilities contain asbestos materials, an attempt should be made to designate those facilities and buildings where it unlikely that ACM will be found, otherwise the information yield from inspections will be unconnected to worker protection. OSHA is using a temporal cut-off of 1980 for its presumption rule. As discussed later, this date was supported by the record, since buildings constructed afterwards are much less likely to contain even stockpiled asbestos containing materials. In 1975, under the authority of the Clean Air Act, EPA banned the use of spray-applied ACM as insulation and the use of asbestos-containing pipe lagging and in 1978 extended the ban to all uses of sprayed-on asbestos. In this regard OSHA notes that the purpose of a cut-off is not to state a date after which it is certain that no asbestos-containing material has been installed in buildings. Rather, it is to designate when it becomes unlikely that asbestos-containing materials have been used in construction. OSHA believes that 1980 is a reasonable date for marking that probability. As noted above, employers and building owners are still required to investigate materials installed after 1980 when they suspect they may be asbestos-containing.

As discussed above, OSHA additionally refined its presumption by recognizing two broad categories of building materials as "high-risk" and thus that the consequences of a false negative identification supported a such materials be treated as asbestos-containing unless reliable information showed the absence of asbestos. These kinds of materials are TSI and sprayed-on, troweled-on, or otherwise applied surfacing materials. Although as noted the version of an inspection rule urged by most proponents would require inspection for all potential asbestos-containing materials, some participants suggested an inspection requirement which would also concentrate on more potentially hazardous materials first. One suggestion was to, first require inspection of steel structures with sprayed on fireproofing constructed before 1975, next of sprayed-on acoustic ceiling installed before 1980 (e.g., Ex. 162-27). In the Agency's view, phasing in inspection requirements may provide less certainty and protection than its presumption approach. Requiring a "presumption" is an immediate source of protection. Any inspection program takes time and significant resources. Additionally, if inspection of categories of potentially high risk material are delayed under a phased-in-approach, protection is denied pending the start-up date. If judicial challenge is made employers may hold back on any inspections hoping for a court to invalidate the requirement. Even more importantly, evidence in the record also indicates that inspection data sometimes are not reliable. In particular, the Westat Report which evaluated a large sample of school inspections under AHERA, found that although on the whole inspections identified most asbestos-containing materials, "high-risk" surfacing material was unidentified as asbestos containing in 36% of the inspections studied (Ex. 1-326 p. 326). Since surfacing material has been found by OSHA, based on this record to be a high hazard material, OSHA is reluctant to rely on inspections alone to identify it. A presumptive approach requires that material which looks like sprayed on or troweled on surfacing material, be handled with care, without waiting for inspections or relying on the results of inspections which may not correctly identify it.

The Agency asked for comment on its intention to designate thermal system insulation and sprayed-on or troweled-on surfacing material as "high-risk material." Several of those responding to the notice felt the list was too limited and should include all suspect materials ( Exs. 162-11, 162-16, 162-18, 162-24, 162-28, 162-33, 162-36, 162-39, 162-42, 162-44, 162-45, 162-46, 162-57). Some, suggested using the list EPA included in its "Green Book" entitled Managing Asbestos in Place (Ex. 162-35, 162-42, 162-44).

G. Siebert of the Office of the Secretary of Defense offered an alternate plan -- a tiered approach in which thermal system insulation and sprayed-on or troweled-on surfacing materials would be considered high-risk PACM and would be labeled and notification carried out: other material which may contain asbestos (Ex. 162-13). He suggested that other material, should be handled as ACM unless sampling indicates that it does not contain asbestos, but that it not be required to be labeled.

As suggested, OSHA considered extending its presumption requirement to other kinds of building materials which may contain asbestos. A limited extension has been made in two cases. Because of its accessibility and prevalence, the frequent difficulty of identifying its asbestos content and the frequency of maintenance activity which may disturb it matrix. The Agency is requiring that resilient flooring installed before 1980 be presumed to contain asbestos unless rebutted pursuant to the standard. Debris which is present in rooms, enclosures or areas where PACM or high risk ACM is present and not intact, is assumed to be asbestos-containing. Other building materials which may contain asbestos such as roofing material, ceiling tiles and miscellaneous products listed in EPA's "Green Book" have not been found to be both as widely prevalent and easily disturbed and damaged as are TSI and surfacing material or as widely prevalent, accessible and frequently disturbed as resilient flooring.

Therefore, OSHA believes little additional benefit will result from treating all such building materials which uncommonly contain asbestos as if they do, rather than concentrating resources on protecting employees from exposure to materials when there is actual knowledge or reason to believe they contain asbestos. OSHA notes in this regard that an employer or building owner's duty to investigate the possibility that a material contains asbestos is stronger when the consequences of failing to inquire is increased hazard to employees. For example, in the case where a large section of damaged ceiling tiles installed before 1980 is to be removed, an employer may not ignore the possibility that the tiles are asbestos-containing. By not including some building materials in the presumption OSHA is not reducing an employer's duty to exercise "due diligence" when exposing employees to such kinds of materials. The Agency has determined merely that the record does not compel the adoption of a presumption for such materials; in any such specific case, circumstances may require the employer or building owner to sample and analyze building materials for asbestos content, or to treat the material as if it is asbestos-containing under the standard.

On a different issue, OSHA is not specifying in the regulatory text the qualifications of the person who may designate materials as PACM. Under AHERA, inspections are required to be conducted by certified inspectors (40 CFR 763, also see recent revisions of Model Accreditation under ASHARA, 59 FR 5236-5260, February 3, 1994). The Agency has found that designation of the kinds of building materials as PACM is not an inspection. This process does not require technical training: thermal system insulation is easily recognized; sprayed on or troweled on surfacing material likewise is identifiable. Neither EPA's revised MAP nor OSHA requires specific training or accreditation of persons who only visually inspect the condition of ACM/PACM.

OSHA emphasizes that the presumption must apply even where it appears to knowledgeable building personnel, that material is not asbestos-containing and is composed of other materials, such as fiberglass. Therefore, OSHA has not adopted the suggestion of some participants to specify that certain materials such as fiberglass and neoprene, because they are easily identifiable, should not be included in the presumption (see Ex. 162-57). OSHA notes that HEI distinguished a "visual survey," i.e., the identification of suspect materials from more complete surveys, and notes that "this type of survey may minimize the need for trained consultants." (HEI, Ex. 1-344, at 5.1) Some participants suggested that OSHA include the condition of the material in its "high-risk" category to be subject to the presumption. Although the condition of the material influences its risk potential, OSHA continues its practice of not distinguishing materials based on their friability. However, the condition of the material is relevant to whether debris, in the presence of ACM, must be presumed to be asbestos containing. The standard requires that debris in an enclosed area where TSI or surfacing ACM is present, and not intact, be presumed to be asbestos-containing.

OSHA has not used friability to distinguish among asbestos containing materials. First, OSHA mainly regulates active disturbances of asbestos, and uses exposure levels as one element in assigning risk-based requirements. Since the friability of material will influence exposure levels, friability is partly subsumed by this reference to exposure levels. Second, the term's precise meaning is unclear, and thus, confusing to the regulated community. The EPA experience in distinguishing risk categories based on friability indicates the complexity of using this concept. In 1973 the EPA-NESHAP had regulated only friable ACM, but later issued a clarification which stated:

* * * Even though the regulations address only material that is presently friable, it does not limit itself to material that is friable at the time of notification. Rather, if at any point during the renovation of demolition additional friable asbestos material is * * * created from non-friable forms, this additional friable material becomes subject to the regulations from the time of creation (Ex. 1-239, p. 48406).

Third, OSHA's risk categories which are based on the type of material include the potential for friability. For example, surfacing material is loosely bound and therefore is potentially more friable than are other materials and thus is considered to present high risk.

The revised rule also allows the building/facility owner or employer to demonstrate, pursuant to specific criteria, that the material does not contain asbestos. The criteria, specified in paragraph (k)(4)(ii) are similar to the inspection protocols for schools in AHERA, such as sampling and analysis by a certified building inspector.

OSHA also considered allowing the use of specific information in the building/facility owner's possession relating to construction specifications to rebut the presumption. However, many who made submissions during the supplementary comment period, pointed out to the Agency that building records were rarely adequate to convincingly establish the absence of ACM in buildings and recommended that they should not be used for rebutting the presumption (Ex. 162-2, 162-4, 162-5, 162-7, 162-11, 162-12, 162-13, 162-19, 162-22, 162-24, 162-25, 162-27, 162-31, 162-32, 162-33, 162-36, 162-39, 162-42, 162-44, 162-45, 162-46, 162-54). Some felt that building records might be useful in confirming, but not rebutting, the presumption, while others deemed the only reliable records were comprised of an AHERA-like comprehensive building survey with bulk sampling data (Ex. 162-1, 162-12, 162-13, 162-24, 162-27, 162-36, 162-50, 162-58). An owner of commercial properties observed that he had often found it easier to sample the PACM than to locate adequate documentation (Ex. 162-29). A group of environmental lawyers recommended that since EPA in its NESHAP rule declined to rely on building records, OSHA should also for consistency (Ex. 162-22). Members of a consulting firm, noted that before 1980, materials containing less than 5% asbestos by volume were said to be asbestos-free (by EPA). Thus, such materials would be unlikely to appear on building records if they had contained less than 5% asbestos (Ex. 162-7).

In considering the numerous comments on the subject, most of which affirmed the general inadequacy of building records to rebut the presumption, OSHA has not included this as a method to establish that a building material does not contain asbestos.

Paragraphs (k)(1)(ii) and (k)(2)(ii) set out the notification provisions for owners and employers. They instruct them concerning who must be notified of the presence of ACM/PACM and how. Briefly, owners must notify employers who bid for work in or, as tenants, will occupy space where ACM/PACM is present. The owner must also notify employees who will perform work subject to this standard in such areas before such work is begun. This work consists of Class I through IV asbestos work, and the installation of new asbestos-containing material. Similar provisions apply to employers who are not owners. [Paragraph (k)(2)(ii)].

The BCTD suggested that notice of ACM take place early in the contracting process (Ex. 162-42) and a representative of the Interstate Natural Gas Association agreed that pre-bid notification of contractors was needed (Ex. 162-9). OSHA agrees. Requiring notification to prospective contractors at bid time will improve employee protection. Knowledge about asbestos presence gained after bidding may cause the bidder to dilute protection in order to salvage the bid. Contractors may lose time and money if they conscientiously stop a job when asbestos is discovered. Other participants echoed these reasons (see, e.g., NCRA, Tr. 2430-2432; Testimony of C. Gowan, Tr. 834-835.) Notifying employers leasing space containing ACM was also recommended (Ex 162-29).

The standard provides that notification may be either in writing or via a personal communication between the owner and persons owed notification or their authorized representatives. OSHA expects that in the case of contracts for work to be performed, notifications will be included in the bid documents. In other cases it may be "faxed," telephoned or otherwise communicated. OSHA believes these notifications, supplemented by clarified labeling requirements [see (k)(7)(vii)], and regulated area posting, will provide ample information to workers so they will not inadvertently be exposed.

During the rulemaking, participants raised various issues concerning notification. Several participants wanted accessibility to be a consideration in the approach (Exs. 162-5, 162-11, 162-14, 162-23, 162-29, 162-30, 162-33, 162-42, 162-49, 162-55, 162-58, 162-59), and BCTD suggested that "accessible" be defined as "material subject to disturbance by building or facility occupants or maintenance personnel or workers performing renovation, repair or demolition inside and/or outside buildings" (Ex. 162-42).

Most agreed that PACM and/or ACM within areas such as mechanical rooms and boiler rooms should be labeled. For example, Mr. Olson of Dow Chemical Company supported the posting of areas where those who may be exposed will see it before working there (Ex. 162-17). A representative from the Department of Defense felt that general posting in public areas would alarm building occupants and over time, lead to reduced credibility and effectiveness (Ex. 162-13). This was echoed in the comments of J. Thornton of Newport News Shipbuilding who felt that signs "may breed complacency" (Ex. 162-21). One participant worried that perhaps a tenant considering renewing his lease who had been notified of PACM within the building might choose to relocate even though there really was no asbestos-containing materials actually present in the building (Ex. 162-20). OSHA has decided that "accessibility" is relevant to posting information concerning the location of in-place asbestos. Paragraph (k)(7)(vii) requires labels to be attached at "accessible locations." OSHA agrees with BCTD's definition as well.

Some representatives of contractor interests recommended that OSHA use as a model for notification the California regulation by which the building owner provides written notification to all building employees, tenants, and contractors (Exs. 162-27, 162-32).

As noted below, paragraph (k)(7)(vii) requires previously installed asbestos products to be labeled in most circumstances; either visibly labeled in accordance with the standard, when feasible, or that information required on the label be posted as close to the installed product as feasible. Information concerning other previously-installed asbestos-containing products must be posted in mechanical rooms or other areas which are accessible where such material is present; or if the products are installed in other areas, the building owner must otherwise make such information available to employees who perform work covered by this standard. The provision exempts from labeling and posting those products which the manufacturer demonstrates cannot release fibers in excess of the PELs. OSHA has found that this exemption will never apply to PACM (TSI or surfacing ACM); rarely will it apply to other asbestos containing materials, because on this record, disturbance of ACM can exceed the PEL. As noted in the comments summarized above, there will be cases where labeling of such materials is not feasible. In such case, the standard requires that signs or labels be displayed as close as feasible to such materials. Additionally, housekeeping workers must be informed that all resilient flooring material they clean, buff or otherwise maintain may contain asbestos.

OSHA believes that the strategy for the flow of information regarding the presence and location of asbestos-containing or presume- asbestos-containing materials it has developed in this revision of its standards will assure that workers who might be exposed to asbestos within public and commercial buildings and/or facilities will be informed of the potential for such exposure and through the training provisions will be made aware of the practices they are to use to avoid exposure.

To further assure the responsible transfer of information, OSHA is requiring that records of the work performed, the location and quantity of ACM or PACM remaining at the completion of the work, and data supporting any rebuttal of the presumption that a material contains asbestos, are to be maintained by the building/facility owner and are to be transferred to successive owners of the building/facility. Further, in the event that ACM/PACM is inadvertently encountered, OSHA has included a requirement for timely notification. If during the course of asbestos work ACM or PACM is discovered at a worksite, within 24 hours of finding such material, information as to its location and quantity are to be conveyed to the building owner and any other employers at the site.

Shipyard Standard

In the reopening of the record for supplemental comments in November 1992, OSHA asked for comment on the application of the proposed scheme for shipyards. There were few specific responses. J. Curran, State of North Carolina Department of Environmental Health and Natural Resources (Ex. 162-46) and BCTD (Ex. 162-42) supported applying the construction standard to shipyards. Mr. Siebert, a representative of the office of the Assistant Secretary of Defense, agreed with others in wanting a separate standard for shipyards to be developed by SESAC (Ex. 162-13).

OSHA has accepted these suggestions and has issued a separate, final standard for shipyards. Its specific provisions are discussed in appropriate places in the preamble. It is more similar to the new construction standard than to the general industry standard.

Training

Paragraph (k)(8) covers training. It expands the training provisions of the current standard considerably. One, training must be given to virtually all employees who are actively exposed to asbestos, i.e. whose exposure is the result of performing Class I through IV work, or who install new asbestos products. Under the unrevised standard, training was triggered by exposure above the action level, i.e. 0.1 f/cc, the new PEL. As discussed above, OSHA has determined that there is a still significant risk at this level. Further, the Agency's experience in enforcing its health and safety standards, along with testimony, comment, and data in this record clearly establish that training of employees is a vital component of any successful program to control exposures to asbestos and other toxic substances. Participants agreed (see e.g., testimony of Dr. Sawyer at Tr. 2164 ". . . (T)rain the worker. I think is the most important factor.") There was substantial record support to expand training. Among those who advocated additional OSHA training requirements were: P. Heffernan of Kaselaan and D'Angelo (Ex. 7-36), K. Churchill of California Association of Asbestos Professionals (Ex. 7-95), D. Kirby of Oak Ridge National Lab (Ex. 77-111), E. Krause of the United Union of Roofers, Waterproofers (Ex. 7-115), G. Lofton of Heat and Frost Insulators and Asbestos Workers Union (Ex. 7-118), P. Curran of North Carolina State Department of Environment, Health, and Natural Resources (Ex. 7-118), W. Dundulis of the State of Rhode Island Department of Health (Ex. 7-124), BCTD (Ex. 119), American Federation of State, County and Municipal Employees (Ex. 141), Service Employees International Unions, AFL-CIO (Ex. 144), National Institute for Occupational Safety and Health (Tr. 230).

Participants supported training all employees who handle asbestos, rather than waiting for significant exposures to trigger it [see e.g., testimony of D. Kirby, Oak Ridge National Laboratory, "You need to have awareness training of . . . custodial and maintenance" people, (Tr 122); and, R. Lemen, NIOSH, who supported ". . . approved training courses for all workers who are routinely handling asbestos containing material, (Tr. 231)]."

The second major expansion of training requirements covers curriculum method and length of training. Before, in the 1986 standard, OSHA merely required that certain topics be covered in the training program.

Subsequently, as OSHA noted in its proposal, and participants noted in their comments, EPA's training requirements under the Asbestos Hazard Response Act (AHERA) become the standard for the asbestos abatement industry. Under AHERA, at the time of the proposal:

. . . Inspectors must take a 3-day training course; management planners must take the inspection course plus an additional 2 days devoted to management planning; and abatement project designers are required to have at least 3 days of training. In addition, asbestos abatement contractors and supervisors must take a 4-day training course and asbestos abatement workers are required to take a 3-day training course. For all disciplines, persons seeking accreditation must also pass an examination and participate in annual re-training courses. A complete description of accreditation requirements can be found in the Model Accreditation Plan at 40 CFR part 763, subpart E, appendix C.I.1.A. through E. (54 Fr, November 29, 1989 at 49190).

More recently, EPA has published an interim rule updating its Model Accreditation Plan (MAP) (59 FR 5236-5260, February 3, 1994) pursuant to the Asbestos School Hazard Abatement Reauthorization Act (ASHARA). Under the revisions, the length of certain courses has increased, i.e. asbestos abatement workers now must take a 4-day, rather than a 3-day course. Additionally, the entire MAP now applies to work in "public and commercial buildings as well as in schools," and requires more "hands-on" training. For example, for abatement workers 14 hours of hands-on training must be included in the 4-day training course.

The training provisions in the new standard correspond to the class of work performed. For Class I and II work, employers must provide employees with a training course which is the equivalent in curriculum, training method and length to the EPA MAP worker training described above. Keying OSHA required training to the AHERA program was supported by many participants; in many sections of the country, most training is now done using AHERA accreditation as the standard for quality, (see e.g., testimony of Daniel Swartzman, School of Public Health, Univ. of Ill, Tr. at 486. et seq.). and because AHERA training as noted above, is the recognized standard for quality in asbestos work (see. must be trained in the proposal, OSHA asked for comment on whether OSHA should provide model curricula and certification for training, and on whether and how OSHA training requirements should be reconciled with those of EPA (55 FR 29726-28).

Much debate on these issues occurred in this rulemaking. Some, most prominently, BCTD, (Ex. 143 at 220 et seq, see also Tr. 483; Tr. 1142, Tr. 3547) stated that OSHA should develop model curricula and certify training courses for asbestos workers. Reasons for this were given as: OSHA's earlier training requirements are inadequate; that "AHERA has proved successful, but needs improvement," and that AHERA should be improved by more "hands-on" training and testing and longer training (see Ex. 143 at 232).

The Agency notes that participants agreeing and disagreeing with the need for OSHA certification of trainers and courses agreed with BCTD's reasons. For example, R. Chadwick the President of Local Union 22 of the International Association of Heat and Frost Insulators and Asbestos Workers, in a letter to OSHA stated that since OSHA stipulated no specific minimum period of training, "Most abatement contractors show a 2-hour film and classify the workers being trained" (Ex. 1-175). OSHA agreed with the above comment that its 1986 training requirements fairly can be considered "bare-bones."

Although BCTD argued that the AHERA model needed improvement, BCTD acknowledged its success in improving worksite conditions (see Ex. 143 at 240, citing Ex. 7-52). EPA itself has improved its training program. As noted above, it recently issued improved model curricula, increasing the training requirements. In particular, the new MAP contains specific "hands-on" training requirements in each major course, including those of workers and supervisors (59 FR 5236-60, February 3, 1994). EPA also increased the number of training hours and now requires 4-day training of workers, and 5-day training of supervisors. Other disciplines of the AHERA program also have increased training requirements.

OSHA has reviewed recommendations carefully and has concluded that requiring OSHA to certify training courses and trainers would consume a disproportionate share of OSHA's resources. Further, establishing another system for certifying asbestos trainers and workers when another agency has a similar program in place would be duplicative of effort as well. OSHA's concerns regarding duplication of effort is also addressed in this preamble in the section on the notification of OSHA vis-a-vis that of EPA under NESHAP.

In addition, other entities have already developed more stringent curricula than those under AHERA. The HEI Report noted that under AHERA each state develops "training and certification programs for inspectors, management planner, asbestos abatement workers and supervisors that were at least as stringent as the AHERA model" (Ex. 1-344, p. 5-51). It further found that a "number of states have developed other requirements that exceeded the AHERA requirement" and that "* * * in some states AHERA certification are required for any asbestos-related work" -- not just for schools.

Paragraphs (k)(8)(i)-(v) cover curricula and length of course requirement. They allow flexibility in the new training provisions. Courses equivalent to those of AHERA (ASHARA) may be substituted, but must be equivalent in curriculum, training method, and length to that of the EPA plan. Thus, employers who in-house training program meets these requirements does not need send all workers off-site for the required training. Several commentaries objected to requiring that all training take place in EPA or state approved training centers, most also praised job-specific training as superior (e.g., Ex. 7-21, 7-39, 7-50, 7-99, 7-100, 7-102, 7-103, 7-108, 7-150).

Training Requirements for Employees Performing Class III and IV Work:

In these standards OSHA does not define the term "custodian" nor do the requirements differ based on the job title. OSHA agrees that in some facilities there is a clear distinction between custodial workers who as a participant noted, "may only * * * strip or buff floor tile or replace light bulbs in fixtures located below ACM" and maintenance workers "who * * * work on building materials or systems that contain asbestos". (ICSC, Ex. 162-58 at 10). Relying on job title, however, to assign duties is inexact and potentially non-protective. Rather in these standards, the nature of the operations performed by that worker determine the level of training required, regardless of job title; janitor, custodian, or maintenance worker. Those who perform only Class IV work must receive at least 2 hours of awareness training, and those who do Class III work must be given 16 hours of training equivalent in content and length to the 16 hour operations and maintenance course developed by EPA (see 40 CFR 763.92(a)(2).

Workers performing these activities may be employees of the building owners or other employers such as outside housekeeping contractors, or trade contractors such as plumbing, electrical, or air conditioning contractors. They must be trained to use appropriate measures to avoid exposure to airborne asbestos.

OSHA in the November 3, 1992 notice, stated that it was considering a training requirement modelled after that of the awareness training required by EPA in its AHERA rule. OSHA further noted that in its training requirements under AHERA, EPA distinguishes between the duties and training of custodial workers and the additional duties and training needs of maintenance and service workers (40 CFR Parts 763). OSHA, too, believes that building/facility workers, who frequently disturb asbestos containing material need more extensive training.

Many who commented during the supplemental comment period agreed that OSHA should use AHERA as a general model for drafting training requirements for building/facility workers (e.g., Ex. 162-13, 162-15, 162-16, 162-18, 162-24, 162-27, 162-30, 162-35, 162-42, 162-44, 162- 45,162-46). Others, felt the existing OSHA training requirements were adequate (e.g., Ex. 162-4, 162-22). Some objected to OSHA specifying a time period in its training requirements (Ex. 162-4, 162-12, 162-17, 162-25, 162-50, 162-55, 162-57). BCTD argued that AHERA training was inadequate for OSHA's purposes, and that any employee in a building containing either ACM or PACM who does not intentionally handle the material should receive at least 4 hours of awareness training and that any worker who disturbs ACM during repair, renovation, demolition or maintenance work needs the full 5-day training course (Ex. 162-42).

Under the training provisions of AHERA, all members of the maintenance and custodial staffs (of schools) who may work in a building containing ACBM are required to receive at least 2 hours of "awareness" training whether or not they are required to work with it (40 CFR 763.92). Those who conduct an activity which will result in disturbance of ACBM shall receive both the awareness training and 14 additional hours of training.

EPA set as a minimum that the awareness training cover:

-- information of uses and forms of asbestos in buildings;
-- information on health effects of exposure to asbestos;
-- location of ACBM in building where employee works;
-- recognition of deteriorating or damaged ACBM; and,
-- the identity of person responsible for management of ACBM.

While the more extensive training needed by those who might disturb ACM include in addition:

-- description of proper methods to handle ACBM;
-- information on respirator protection
-- the provisions of the AHERA rule; and,
-- hands-on training on the use of protective equipment and work practices

 

Information in this rulemaking discussed above shows that workers who have performed work now designated Class III and IV have developed asbestos-related disease. Because as noted above, training is one of the most powerful instruments to protect workers, OSHA believes that its former training provisions must be improved by incorporating additional curricula such as covered in the AHERA courses for such workers. Imposing time criteria for courses will help insure that sufficient time for instruction is provided. More time can always be allotted, as needed.

(12) Housekeeping

Paragraph (k) General Industry Standard. Paragraph (l) Construction and Shipyard Employment Standards:

Housekeeping practices have been shown to be effective means of reducing employee exposure to asbestos. OSHA is specifying that the now required cleaning of floors and surfaces on which dust containing asbestos can accumulate be performed at least once per shift in primary and secondary manufacturing. In addition to the current requirement that a vacuum containing a HEPA-filter must be used, where feasible, wet methods must also be used for clean-up. Once asbestos dust is entrained, it can accumulate on surfaces leading to potentially substantial levels of exposure. Routine removal of dust can greatly reduce these accumulations and the risks that they pose.

There was little over-all objection to this provision from the participants in the rulemaking process. However, the Asbestos Information Association asked that OSHA not revise the current housekeeping requirements which specify that all surfaces be maintained as free as practicable of accumulation of dusts and wastes containing asbestos (Ex. 142, p. 7). They argue that if OSHA requires once per shift vacuuming, it would lead to less effective housekeeping efforts since vacuuming might then occur at a later time in the areas most in need of housekeeping than occurs with current cleanup whenever a fiber accumulation occurs." OSHA is unconvinced by this argument. If the employer believes that more frequent cleanup is needed, it should be performed. The standard merely requires that vacuuming be done no less often than once per shift. The employer can determine when during a shift, vacuuming is most useful and perform it then.

Flooring Maintenance Requirements

There are now a new Sec. Sec. 1926.1101 (g)(2)(iv) and 1910.1001(f)(1)(xi), which prohibit the sanding of floor tiles containing asbestos. Further, only low abrasion pads may be used at speeds lower than 300 rpm in "stripping" operations, and stripping of unwaxed or unfinished floor tile containing asbestos is prohibited. OSHA believes that without such restrictions this type of mechanized activity may result in the release of significant levels of asbestos fibers into the air. In addition, the new provisions allow asbestos-containing floors to be mechanically buffed without limitation on the speed of the buffing machine, so long as the floor has sufficient finish to preclude contact between the pad and the asbestos-containing material. In most cases, at least 3 layers of wax will provide that margin. If the manufacturer's instructions specify a thicker wax layer, those instructions must be followed. (See testimony of J. Harless of Pioneer Eclipse, ISSA).

These requirements are changed in some respects from the July, 1990 proposal, which would have further restricted stripping and burnishing activities. The prohibition concerning "sanding" of asbestos-containing floors was supported by ISSA and others, and it unchanged from the proposal. (See Ex. 136D). The changes from the proposal reflect the comments and data submitted to the record. The data show that now permitted activities are not expected to result in the release of significant asbestos contamination. In addition, since OSHA's proposal had used various terms relating to floor care imprecisely, the final provisions conform the language to the common understandings of the floor care industry. Thus, "stripping" is defined as a wet process to remove the floor polish or finish using chemical strippers, or abrasive pads. (See Ex. 136D, ISSA's comments). "Burnishing" is dry buffing of floor polish by a high-speed rotary disc machine or otherwise.

The core requirements of OSHA's new provisions are that no "sanding", i.e. the abrading of asbestos-containing material to even out the surface, is allowed: that "stripping" of finishes of asbestos-containing flooring must be conducted wet using the least abrasive pad possible; and that burnishing may be performed only on floors which have sufficient finish so that the pad does not contact the unfinished asbestos-containing material. OSHA believes that these three principles of asbestos-containing floor maintenance are sufficiently clear and flexible to apply to all kinds of floor maintenance activities, even if the activity is described using different terminology.

OSHA is basing these provisions primarily on the results of studies submitted during the rulemaking. Thus, in the most thorough and detailed study submitted to date on this topic, BCTD furnished a copy of a study by T. Marxhausen and S. Shaffer entitled "Vinyl Asbestos Tile: A study of airborne asbestos concentrations during routine floor maintenance activities." (Ex. 119X) In this study both TEM and PCM measurements were made during several operations. The results are briefly summarized in Table VIII.

Table VIII. Asbestos Fiber Levels During Floor Maintenance Activities

[Ex. 119K]
Location TEM s/cc PCM f/cc
Room F1 during low speed with red pad 0.069 0.0215
Room F2 during high speed scrub with white pad .533 .016
Room F2 during stripping with black pad 1.450 .0045
Room F1 during stripping with black pad 1.153 .007
Room F1 during high speed burnishing with white pad
(after finish build-up)
.069 (1)
Room F2 during high speed scrub with white pad .533 .016
Room F2 during high speed scrub with white pad
(after finish build-up)
.111 (1)
Room F1 during high speed scrub with white pad
(after finish build-up)
.130 .034
  • Footnote(1) Not available

The authors found that approximately 97% of the asbestos structures observed during all analyses were less than 5 microns in length (and would therefore not be seen by PCM). They concluded that "Concentrations were low during low speed scrubs and burnishing of freshly built-up, new floor finishes. High speed scrub results were highest on the worn floor but dropped to approximately one-fifth this level on freshly built-up surfaces." The authors noted that although high speed scrubs and burnishing operations used the same machine and pad, the fiber levels observed in high speed scrub operations were higher than during burnishing. They hypothesized that this had been due to condition of the floor tested or that "the limited amount of cleaning solution causes the higher values observed during high speed scrubbing operations." They expressed serious concern about the elevated TEM measurements during some of these operations and called for more extensive study.

S. Wong, Director of Environmental Health and Safety Branch of the Los Angeles Unified School District submitted a report of a study in which fiber levels were measured by TEM during various floor maintenance activities (Ex. 7-11). Using a pass-fail criterion of 5 samples less than or equal to 70 structures per square millimeter (the AHERA clearance level), she found that 5 of 7 stripping pads failed. She also found that use of a brush with a rotary powered scrubbing machine passed and that various stripping solution used in conjunction with the brush also passed. Repeated use of a pad which initially passed, continued to do so. In a final test using one of the stripping solutions and 7 other brushes, all failed. However, neither the OSHA PEL nor action level was exceeded. The report concluded with several recommendations: (1) all VAT floor maintenance using powered equipment be performed using wet methods exclusively; (2) that use of aggressive pads results in release of fibers from previously applied wax (They found 5% fibers in the old wax scraped from baseboards.) and their use should be discontinued; (3) schools continue to use only the off-white or pink pad which passed for buffing; (4) recommends discontinuance of use of power equipment to strip wax from floors unless they do not contain asbestos; and, (5) alter maintenance program to perform frequent damp mopping and less frequent stripping.

Both studies cited above were conducted after the A.F. Meyer study discussed in the proposal, which was conducted in October 1989, and which showed slightly elevated asbestos levels after routine buffing (with standard red buffing pad and standard buffing solution) and stripping. No levels, however, exceeded OSHA's proposed PELs. Two methods were used for stripping: (1) standard stripping mixture mopped on and standard black stripping pad, and (2) mist spray of stripper solution and standard black stripping pad. As noted in the proposal, the stripping conducted using a mist spray of stripping solution and the more abrasive pad resulted in significantly higher asbestos fiber airborne concentrations than the first method.

On January 25, 1990, in response to the A.F. Meyer study, EPA published a "Recommended Interim Guidance for Maintenance of Asbestos-Containing Floor Coverings," (Ex. 1-108) outlining its analysis of the Meyer's findings. The Agency concluded that, although there was "no clear evidence" that "routine" stripping significantly elevated levels of asbestos fibers, it observed that higher levels did occur after a stripping machine was used on a relatively dry, unwaxed floor.

Work practices recommended by EPA in the same guidance memo emphasize the same precautions contained in OSHA's final standards: viz. that the least abrasive pad be used for stripping, and that low speed equipment be used for stripping of floors.

OSHA notes that ACCSH's recommendations for work practices in floor maintenance also echo the themes of wet stripping, using the least abrasive pad for stripping, limiting the speed of the machine and prohibiting floor sanding, which are the core requirements in this standard. (Ex. 1-126).

In a change from the proposal, OSHA is permitting high speed buffing of finished floors containing asbestos material. A number of participants pointed out to OSHA that buffing, although performed at high speed, is done on 3 to 5 layers of wax, unlike sanding, and that the wax, not the tile, is polished in this process. (Ex. 7-19, 7-80, 7-84, 7-90, 7-100, 7-107, 7-123, 7-142, 7-188, 125D, 147 and Tr. at 3599). Michael B. Wheeler Chief Executive Officer of Essential Industries Inc., stated that:

Stripping is expensive, labor and material-intensive, and, in the context of vinyl asbestos tile something we wish to keep to a minimum. Ultra high speed maintenance techniques allow workers in heavy trafficked stores to strip their finished floors every 10-18 months as compared to every 2-3 months using older low speed techniques. (Ex. 7-188).

He went on to explain that these high speed techniques also reduce the labor requirements by at least half. He cited studies using low speed spray buffing techniques on finished VAT which yielded fiber levels ranging from 0.015 to 0.025 f/cc and quoted the WRC-TV report that "just buffing an already waxed floor does not throw up any asbestos from the asbestos tile." In addition, ISSA described additional floor maintenance procedures which increase the glossiness of the floor -- spray buffing (done at 175-300 rpm) and burnishing (done at 300-2,000 rpm). ISSA stated that if there is finish on the floor surface, these procedures do not generate unsafe levels of fibers because they do not contact the floor itself. They oppose OSHA's proposed changes prohibiting speeds of more than 190 rpm in floor machines, particularly due to increased costs in time and money. (Ex. 136D).

Based on this record, OSHA believes that employees who burnish and/ or buff floors using high speed floor machines will be exposed to minimal asbestos fiber concentrations if the floor machines are used to polish finished or polished floors, and if the pad does not contact the unpolished floor. Industry also claims that the use of high speed buffing will increase the intervals where stripping is required, and thus, may reduce risk to employees who perform floor maintenance, but OSHA is not relying on this speculative benefit.

(13) Medical Surveillance

Paragraph (l) General Industry Standard. Paragraph (m) Construction and Shipyard Employment Standards.

No changes were made to this section. The medical surveillance provisions in the 1986 construction standard are now also included in the shipyard employment standard.

(14) Recordkeeping

Paragraph (m) General Industry Standard. Paragraph (n) Construction and Shipyard Employment Standards. The recordkeeping provisions now include provisions (n)(5) and (n)(6) which require maintenance of data used to rebut the presumption that a contains asbestos, i.e., the building owner/employer who relies on data to demonstrate that PACM is not asbestos-containing must maintain the data upon which he relied for as long as they are used to rebut the presumption. In addition, where the building owner has received or provided information concerning the location, amount and identify of ACM and PACM, he must maintain written records of them and their content for the duration of ownership and must transfer them to successive owners.

(15) Competent Person

Paragraph (o) Construction and Shipyard Employment Standards. OSHA is adopting as final provisions most of the proposed changes to the 1986 construction standard's requirements concerning the designation of a "competent person" on certain construction worksites. The term "competent person" is derived from the generic construction standard's provisions. Under these, employers must designate a "competent person" on all construction worksites to conduct "frequent and regular inspections of the job sites, materials, and equipment" as part of required safety and health programs (Sec. 1926.20). At the suggestion of SESAC, OSHA has designated that the person who performs the shipyard duties analogous to the competent person in the construction standard will be termed a "qualified person." For the purposes of the present discussion these terms are equivalent and will be discussed as "competent person." The 1986 asbestos construction standard appeared to limit this requirement. "Competent person" supervision was required only at removal, demolition, and renovation operations which were not "small-scale, short-duration," but under the asbestos standard, the competent person was to be specially trained in asbestos hazards, and perform various duties mainly involving the setting up and control of the NPE, and the supervision of workers within the enclosure (formerly 1926.58(e)(6)(ii)).

The Court of Appeals, agreeing with BCTD, instructed OSHA to either expand the "competent person" requirement or explain more persuasively why it refused to do so. OSHA agrees that for all construction work involving asbestos exposure under this standard, a "competent person" who is specially trained in asbestos related work conditions, should either be available to employees or be present on the work site. Like other provisions in this standard, the more risky asbestos work deserves a more protective provision; so employees performing Class I and II work will have the benefit of a "competent person" on the worksite, to the extent necessary to perform his duties as set out in paragraph (o). Employees performing Class III and IV work, will be entitled to access to a "competent person" as needed.

Two issues regarding the "competent person" were discussed during the rulemaking. One was the training required; and two, whether or not the competent person needs to be present throughout the operation.

As to the second issue, the standard requires in paragraph (o)(2) and (3), that the competent person must perform the "frequent and regular inspections of the job sites, material and equipment" to accomplish "health and safety programs," which are otherwise required by the general construction provision in Sec. 1926.20(b)(2). Although no elaboration of this provision is provided, OSHA intends that in all work covered by this standard, including Class IV work and work not included in a "Class," a competent person insures, by inspecting the worksite, that workers exposed to asbestos are protected by the relevant provisions of this standard, and that they are informed pursuant to paragraph (k) of this standard about the presence and location of ACM and PACM. Additionally, paragraph (o)(3) requires that in Class I operations the "competent person" must make on-site inspections at least once during the workshift and any time at employee request. In addition, the list of specific duties of the "competent person" in paragraph (o)(3)(i) for Class I and II work includes specific language requiring the required supervision of various controls and work practices to be made through "on-site inspection."

The record supports the need for on-site supervision of setting up of controls. Chip D'Angelo, when asked what were his major concern about glove bags, testified that "Just the act of attaching * * * concerns us * * * a lot of times the material is so overly dry and very loose * * * simply attaching the bag can create some problems * * * Removing the bag, if not done properly and evacuated properly and twisted properly, actually expels fibers out into the air" (Tr. 3126). For example, he/she must be present when a glove bag is attached and determine that a smoke test is passed and again be present when the bag is removed. It is not necessary that the competent person continually watch the operation, rather that he oversees its proper completion. OSHA has not specified the ratio of on-site supervisors to abatement workers. Mr. Booher of Exxon Company, testified that "if you have three glove bag operations going on next to one another, in close proximity to one another, that one competent person can handle up to three jobs effectively" (Tr. 2677). The Agency believes that various operations need closer supervision than others; the exposure assessment should clarify how close supervision needs to be. So long as the specific activities in the standard requiring inspection are covered, the extent of the required inspections are up to the judgment of the "competent person."

Training for the competent person is the same for those who supervise Class I and II asbestos work under the standard. The training must be obtained in a course which is the equivalent of the EPA supervisor course. Unlike the training requirements for workers for Class II jobs which may concentrate on a particular kind of material if that is the only asbestos work which an employee does, the "competent person" supervising Class II jobs must be trained comprehensively in all aspects of asbestos related construction work. Thus, for example, a flooring removal supervisor must be informed about all asbestos removal control methods: this is the person who must evaluate a prospective job to assure that the PELs will not be exceeded, who must choose among available controls to reduce exposures, and must know how to supervise extensive control systems if they are needed for high exposure Class II work.

The training requirements of persons supervising Class III work are different. Most Class III work is maintaining or renovating building components. Supervisors of such work need not be trained in methods of abating asbestos material on a large scale. The EPA asbestos in schools rules, now updated to encompass commercial and public buildings requires that maintenance workers in asbestos-containing buildings be trained in a 16-hour course which includes; proper asbestos-related work practices, waste handling and disposal, respirator use, decontamination procedures, and the content of applicable Federal, state and local asbestos regulations. All Class III workers and their supervisors must take such a course, which covers all control measures required for Class III work. In this regard OSHA notes comments which stated that training supervisors of plumbers, pipefitters, and sheet metal workers, who are engaged in projects of incidental removal that are small scale and short term, in full enclosure techniques is wasteful (see e.g. Ex. 7-151, 152, 153).

Although the formal training for supervisors and workers in Class III work is the same, additional criteria for "competency" contained in the general construction standard distinguish worker and supervisor on all asbestos jobs, including Class III.

Thus, the "competent person" must be "capable of identifying existing and predictable hazards * * * which are * * * hazardous to employees, and (have) authorization to take prompt corrective measures to eliminate them" (29 CFR 1926.32(f)). Also, the "competent person" must be designated by the employer (29 CFR 1926.20(b)(2)). OSHA notes that the "competency" of the competent person is independent of the training required. "Competency" as well as training is required. Thus, a "competent person" is not merely someone with a specified level of training but connotes a high level of knowledge of worksite safety and health issues as well.

The need for a high degree of expertise for Class III work was acknowledged by labor representatives. (See ACCSH reference in the proposal at 55 FR 29727, and R. Gobbell's testimony (Tr. 4318). Employer representatives questioned the need for this uniform training requirements for competent persons supervising all asbestos work, but also acknowledged that supervisors of maintenance projects needed training in the control methods required (See e.g.Ex. 7-151, 7-152, 153); others stated that in-house training was often superior to EPA's (see e.g. Amoco Corporation, Ex. 7-37); and that trained competent persons should be allowed to train other workers (Gulf Power Company, Ex. 7-50). OSHA is allowing in-house training so long as it meets the criteria for curriculum, length, and method of training contained in the standard.

Training for "competent persons" for Class IV work depends on when that work is performed. When Class IV workers perform their duties in facilities and buildings where no other asbestos work is taking place, the "competent person" supervising them must be trained in an EPA accredited course on operations and maintenance workers or its equivalent, much as for Class III work. If clean-up work is done within a regulated area, supervision of the clean-up must be conducted by the "competent person" who is supervising the asbestos job for which the area was established, which in most cases will be Class I and II work.

A number of participants in the rulemaking, primarily representing industry interests, objected to the proposed requirement for a competent person specifically trained in an EPA-approved course to oversee workers performing small-scale, short duration asbestos jobs. These included: J. Bavan of Michigan Consumers Power (Ex 7-21), Mr. Quanstrom of Amoco Corporation who felt in-house training was often superior to EPA's (Ex. 7-37), and others contain virtually identical comments in which the plumbing contractors state their support.

Based on the record evidence, OSHA concludes that its expansion of the competent person requirements and additional requirements for training are appropriate.

Shipyard Employment Standard

SESAC agreed that asbestos operations should be overseen by personnel who have the qualifications to ensure that asbestos operations are performed safely; however, they noted in their submission (Ex. 7-77) that in existing OSHA shipyard standards, the term competent person(s) has been used to refer to a person who is uniquely qualified to perform entry tests preparatory to entering enclosed and confined spaces and felt that the use of this term as employed in the asbestos standard would cause confusion. They suggested that the competent person be called a "qualified" person in the shipyard standard. OSHA does not object to this substitution of terms, but notes that all requirements for competent/qualified person(s) are to be equivalent.

SESAC also pointed to a process which may be the general case in large operations, in which the duties of the shipyard qualified person are shared or divided between two or more persons. That is, in some of the larger companies represented on the committee, a training department (not a person) is responsible for ensuring that employees are trained and another department is responsible for setting up the regulated area, while an industrial hygiene department conducts all monitoring. SESAC recommended that this be specifically allowed. OSHA feels that the current regulatory language permits utilizing this organization of responsibilities and agrees with the suggestion that it is appropriate for shipyards.

(p) Dates

The amendments to the General Industry and Construction Standards and the new Shipyard Employment Standard become effective 60 days after date of publication in the Federal Register. All existing provisions remain in effect (including coverage of Shipyards by the General Industry Standard) until the new provision's start-up dates. Various start-up dates are set forth in the standards. Where there is no start-up date for a provision, the start-up date is the effective date. If any new or amended provision is stayed by OSHA or a court or vacated by a court, the pre-existing provision becomes binding again.

Appendices

Appendices A, C, D, E, and F of the General Industry Standard are binding. Appendices A, C, D, and E of the Construction Standard are binding. Appendices A, C, D, E, J, and L are binding in the Shipyard Employment Standard. Appendices B, H, I, and J of the General Industry Standard are not binding. Appendices B, F, H, I, and K of the Construction Standard are not binding. Appendices B, F, H, I, and K of the Shipyard Employment Standard are not binding. They are intended neither to add to or detract from binding requirements.

Shipyard Employment Standard. With respect to the appendices to the standard, SESAC recommended inclusion of the appendix dealing with work practices and engineering controls for automotive brake and clutch repair and assembly in the shipyard standard. OSHA agrees that this appendix is appropriate to the shipyard employment standard, since these activities occur within shipyards and has included this as appendix L in the shipyard employment standard. OSHA further notes that this appendix has been amended subsequent to consideration by SESAC, and therefore differs from the alternate regulatory language suggested by the committee. For example, the Agency no longer considers the solvent spray can a preferred method for controlling asbestos contamination and will not include it in either standard.

Appendix A

All changes indicated in this document are to be made to Appendix A of the asbestos standards and all changes are the same for 1910.1001, 1915.1001, and 1926.1101.

In the explanatory paragraph at the beginning of Appendix A phrase:

"(such as the NIOSH 7400 Method)" is replaced with:

"(such as Appendix B of this regulation, the most current version of the OSHA method ID-160, or the most current version of the NIOSH Method 7400)."

This change is made to assure that the analytical methodologies followed are the most current and reliable available. Appendix B of this standard has been updated and is the most current version of OSHA ID-160. This method was written to adhere to the language of Appendix A so that there would be no confusion about the limits of the sampling and analytical parameters such as flow rates. So long as parameters consistent with Appendix A are used, there will be no analytical differences between ID-160 and NIOSH 7400 methods.

Sampling and Analytical Procedure paragraph 2:

The following sentence is added to the end of the paragraph:

"Do not reuse or reload cassettes for asbestos sample collection."

The practice of reusing cassettes can result in lower estimates of employee exposure. Adequate cleaning of the cassettes cannot be assured. Fibers from the cassette may become dislodged and be collected on the filter during subsequent sampling. Employee exposure assessments are often assessed based on a small number of fibers. This is because it is not possible in every work place to use single cassettes for an entire work shift due to excess dust in the air. This is significant for occupational exposures, because the background fiber concentration must be subtracted from the compliance sample. If fugitive fibers from used cassettes were deposited on the blank filter, the background estimate would be artificially high and the employee exposure will be underestimated when the background concentration is subtracted as required. Elimination of the practice of reusing cassettes will eliminate this source of error, thereby better assessing employee exposure. A requirement that cassette reuse not be allowed is added to the end of paragraph 2 of Appendix A.

Paragraph 11 is revised as follows:

11. Each set of samples taken will include 10% field blanks or a minimum of 2 field blanks. These blanks must come from the same lot as the filters used for sample collection. The field blank results shall be averaged and subtracted from the analytical results before reporting. A set consists of any sample or group of samples for which an evaluation for this standard must be made. Any samples represented by a field blank having a fiber count in excess of the detection limit of the method being used shall be rejected.

The original wording of the standard was inadequate to apply meaningfully to certain sampling practices, such as continuous sampling. This change establishes that the blanks are to be field blanks. This wording also establishes when blanks are to be taken. The specific practice to be followed for blank correction is outlined in Appendix B, the detailed analytical method. Each time an evaluation of work place exposure is made for the purposes of this standard, the samples used in that evaluation must be represented by valid blanks taken in the work space where the compliance samples were taken.

The following changes apply to the Quality Control Section. Paragraph 2 is renumbered 2(a). Since the standard was promulgated, the lack of a specific requirement to participate the Program for Analytical Testing (PAT) has led to confusion with the requirement that laboratories participate in a round robin using samples taken from real world samples.

A second paragraph is added directly following 2(a) and is denoted 2(b).

2(b) All laboratories should participate in a national sample testing scheme such as the Proficiency Analytical Testing Program (PAT), the Asbestos Registry sponsored by the American Industrial Hygiene Association (AIHA).

This is a requirement of OSHA method ID-160 and NIOSH 7400. This requirement was originally left out of the standard because of the uncertain status of the PAT program at the time of promulgation of the standard. Inclusion at this time is to make it clear that the required participation in a round robin indicated in paragraph 2(a) is not satisfied by participation in the PAT program. Such participation is however, highly desirable and may be required for private accreditation.

Since the original promulgation of the asbestos standards, there have been several improvements and refinements to the analytical procedure. Two major analytical methods reflect these changes and continue to be updated as necessary. The changes are mostly procedural, providing safer analysis and clearer descriptions of the procedures that are to be carried out. As a result, Appendix A and Appendix B have been updated to reflect the most recent refinements.

Changes to the mandatory asbestos method Appendix A are intended to clarify some of the requirements of the method. Wording has been inserted to indicate what methods are acceptable. A definition of what constitutes a "set" of asbestos samples was added to more clearly define when blank samples are to be taken and to reinforce that they are to be field samples.

Paragraph 11 is amended to clarify what a set of samples is and when it is necessary to take blank samples.

An early draft version of NIOSH method 7400 was used for the model of Appendix B. There were several problems with the method including the potentially dangerous practice of boiling acetone. This appendix has been replaced entirely with the most current version of OSHA method ID-160 Asbestos in Air. The OSHA ID-160 give the same results as NIOSH 7400 when used within the sampling constraints imposed by Appendix A, notably the flow rate limits of between 0.5 and 5 liters per minute for the 25 mm cassette and 1 to 5 for the 37 mm cassette. The counting rules are functionally the same for both methods. Use of Appendix B, OSHA ID-160 or NIOSH method 7400 when used within the constraints of Appendix A are all acceptable and equivalent. Appendix B is the same as OSHA method ID-160 on the date of publication of these changes. It, like NIOSH method 7400, is subject to change when such changes will result in better methodology.

As the PEL has been lowered to 0.1 fiber/cc, there is an increased concern about sample overloading as voiced by several commentors such as the American Industrial Hygiene Association (AIHA). Such overloading is the presence of non-asbestos dust on the surface of the filter obscuring the filter surface. Such dust has been shown to decrease the number of fibers counted even before the surface is fully obscured. Some employers have taken samples in such a way that there are no representative samples for the work being performed because all of the filters have been obscured by excess dust. The intention of Appendix A is to provide for the most precise measurement possible while allowing for the fact that many work places have an exceeding amount of non-asbestos dust. Appendix A suggests that a sample be collected such that there are a minimum of 100 fibers/mm(2). In many work places this is not possible. It is preferable to collect a sample that can be used to estimate the asbestos concentration even if it is with a higher than ideal error level than it is to collect a large volume and completely obscure the filter rendering the sample useless.

An acceptable weight of dust on the filter is highly dependent on the average particle size of the dust. Very small particles such as those from diesel exhaust will quickly obscure the filter with very little weight (much less than 1 mg on the filter). On the other hand, large particles may load the weight up beyond several milligrams with little loss in fiber count. For 5 micrometer diameter particles with a density of 3, 25% of the filter area will be obscured with a total weight on the filter of 1mg. Increasing the average diameter of the particles to 10 micrometers will double the allowable weight to 2mg. It is very important for the person conducting sampling to be careful about the dust levels in the air. It is acceptable to take a series of samples to model the work place air when serial sampling will result in samples that can be used. Serial sampling has the additional benefit that higher asbestos concentrations can be measured by reducing the volume of air drawn through each filter.

Appendix G

OSHA is removing appendix G from the construction standard. The rulemaking proceeding and the Agency's experience enforcing the unrevised standard showed that this "non-mandatory" appendix was unclear and that portions of it belonged in the regulatory text. Former appendix G covered controls for all four classes of asbestos work. Therefore, OSHA has extracted the main provisions covering various controls and practices required for each class and placed them as discussed in the regulatory text applying to each operation covered.

OSHA knows that some employers would like additional guidance on specifications for required work practices and controls. The EPA "Greenbook," (Ex. 1-183), NIBS Guidance Manual (Ex. 1-371) and other sources of specific work practices are available.

Appendix J

OSHA method ID-191 for bulk asbestos analysis has been included as Appendix J, to provide a suggested uniform method for the identification of asbestos. This method uses polarized light optics on a phase contrast microscope. Using this methodology, fibers visible in phase contrast illumination can be viewed to assess whether there might be potential for asbestos exposure from a material which can be measured by a phase contrast counting method. This method also contains the criteria used by OSHA to differentiate between asbestiform and non-habit of minerals. The text of the method is informational and explains its limitations and proper use.

Environmental Assessment; Findings of No Significant Impact

OSHA has reviewed the environmental impact in accordance with the requirements of the National Environmental Policy Act (NEPA) of 1969 (42 U.S.C. 4321 et seq.), the Council on Environmental Quality (CEQ) NEPA regulations (40 CFR Part 1500), and OSHA's NEPA compliance procedures (29 CFR Part 11).

As a result of this review, OSHA has determined that these regulations will have no impact on air, water or soil quality, plant or animal life, or the use of land or aspects of the external environment. Therefore, OSHA concludes there will be no significant impact on the general quality of the human environment outside the workplace, particularly in terms of ambient air quality, water quality, or solid waste disposal. No comments made at the public hearing or submitted to the record contradict this conclusion.

State Plan Requirements

The 25 States and territories with their own OSHA-approved occupational safety and health plans must revise their existing standards within six months of the publication date of the final standards or show OSHA why there is no need for action, e.g., because existing state standards are already "at least as effective" as the new Federal standards. These States are: California, Connecticut (State and local government workers only), Hawaii, Indiana, Iowa, Kentucky, Maryland, Michigan Minnesota, Nevada, New Mexico, New York (State and local government workers only), North Carolina, Tennessee, Utah, Vermont, Virginia, Virgin Islands, Washington and Wyoming. Until such time as a State standard is promulgated, Federal OSHA will provide interim enforcement assistance, as appropriate.

Federalism

The standard has been reviewed in accordance with Executive Order 12866 (52 FR 41685; October 30, 1987) regarding Federalism. This Order requires that agencies, to the extent possible, refrain from limiting State policy options, consult with States prior to taking any actions that would restrict State policy options, and take such actions only when there is clear constitutional authority and the presence of a problem of national scope. The Order provides for preemption of State law only if there is a clear constitutional authority and the presence of a problem of national scope. Additionally, the Order provides for preemption of State law only if there is a clear Congressional intent for the agency to do so. Any such preemption is to be limited to the extent possible.

Section 18 of the Occupational Safety and Health Act (OSH Act), expresses Congress' clear intent to preempt State laws relating to issues with respect to which Federal OSHA has promulgated occupational safety or health standards. Under the OSH Act a State can avoid preemption only if it submits, and obtains Federal approval of, a plan for the development of such standards and their enforcement. Occupational safety and health standards developed by such Plan-States must, among other things, be at least as effective in providing safe and healthful employment and places of employment as the Federal standards.

The Federally promulgated Asbestos standard is drafted so that workers in every State would be protected by general, performance-oriented standards. To the extent that there are State or regional peculiarities that could alter work practices, States with occupational safety and health plans approved under section 18 of the OSH Act would be able to develop their own State standards to deal with any special problems. Moreover, the performance nature of this final standard, of and by itself, allows for flexibility by States and contractors to provide as much safety as possible using varying methods consonant with conditions in each State.

In short, there is a clear national problem related to occupational safety and health of workers. While the individual States, if all acted, might be able collectively to deal with the safety problems involved; most have not elected to do so in the twenty-three years since the enactment if the OSH Act. Those States which have elected to participate under section 18 of the OSHA Act would not be preempted by this final regulation and would be able to deal with special, local conditions within the framework provided by this performance-oriented standard while ensuring that their standards are at least as effective as the Federal standard.

IV. Final Regulatory Impact and Regulatory Flexibility Analysis

A. Introduction

In this final revision to the asbestos standard for construction, general industry and shipyards, OSHA is lowering the permissible exposure limit in all affected industry sectors to 0.1 f/cc as an 8-hour time-weighted average. In addition, OSHA is revising ancillary requirements in the current standard to respond to three issues remanded to the Agency by the Court. These issues involved expanded competent person training, clarification of the definition for small-scale, short-duration construction projects, and reporting and transfer requirements in construction. Also, permissible controls in brake and clutch operations are addressed in a revision to the standard for general industry.

Executive Order 12866 requires that a regulatory impact analysis be prepared for any regulation that meets the criteria for a "significant regulatory action." Among these criteria, relevant to this rulemaking is the requirement that the rule have an annual effect on the economy of $100 million or more or adversely affect in a material way the economy, a sector of the economy, productivity, competition, jobs, the environment, public health or safety, or State, local, or tribal governments or communities.

Consistent with these requirements, OSHA has made a determination that the final revised standard will constitute a significant regulatory action. Accordingly, OSHA has prepared this Final Regulatory Impact and Regulatory Flexibility Analysis to demonstrate the technological and economic feasibility of the final revision.

B. Industry Profile

Characteristics and Properties of Asbestos

Asbestos is the generic term applied to a group of naturally-occurring, fibrous silicates characterized by high tensile strength,(1) flexibility, and resistance to thermal, chemical, and electrical conditions. According to the Bureau of Mines, a number of silicates occur naturally in fibrous form, however, not all of these mineral forms are labeled asbestos. Historically, only minerals with (1) commercial importance (2) a crystalline structure with fiber growth along two planes (i.e., lengthwise) and (3) sufficient fiber growth such that the fibers can be identified, separated, and processed, are given the name asbestos [Campbell, 1977].

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Footnote(1) Tensile strength is defined as the resistance of a material to a force tending to tear it apart.

Asbestos silicates are divided into two mineral groups: serpentine and amphiboles. Both groups are widely distributed in the earth's crust in many igneous and metamorphic rocks. In rare instances, these mineral deposits contain sufficient quantities of usable asbestiform minerals rendering it profitable to mine for commercial asbestos. Some types of commercial asbestos have the properties of softness, silkiness and flexibility that, among other uses, permits them to be spun into thread from which cloth can be woven. This variety, found in the serpentine group and given the name chrysotile, is by far the most abundant of the asbestos minerals, comprising over 90 percent of world production. Five other commercial varieties -- riebeckite (crocidolite), grunerite (amosite), anthophyllite, tremolite, and actinolite -- belong to the amphibole group and, unlike the serpentines, are characterized by hard and brittle fibers. Chrysotile, amosite, and crocidolite all have extremely high tensile strengths and have been used extensively as reinforcers in cements, resins, and plastics.

Asbestos Production, Consumption, and Use

In the production process, asbestos ore is mined and then milled to achieve a homogeneous, graded input. Raw asbestos is shipped to primary industries to be processed into intermediate or finished products. For some goods, secondary manufacturing may be necessary to complete the production process. The finished product is then sold to construction/ consumer industries for application, installation or erection without further modification.

Domestically used asbestos fibers are technically classified into seven quality categories, or grades, with the longer, higher-strength fibers given lower-numbered grade levels.

Table 1 presents the 1992 distribution of asbestos consumption in the United States, by end use, type and grade. Historically, Grades 1, 2 and 3 were used for relatively refined uses such as textiles, electrical insulation, and pharmaceutical and beverage filters. With the introduction of ceramic fibers, fibrous glass, cellulose fibers and other substitutes, use of asbestos in these and other products has declined in recent years. As Table 1 shows, U.S. consumption of chrysotile asbestos is concentrated in Grade 7, whose shorter, lower-strength fibers are used as reinforcers in coatings and compounds, clutch facings and brake linings (friction products), packing and gaskets, and roofing products.

Table 1. -- U.S. Asbestos Consumption By End Use, Type and Grade

(For Table 1, see printed copy)

Total U.S. asbestos consumption declined 6 percent in 1992 from a level of roughly 35 thousand metric tons(2) a year earlier. Of the 32.8 thousand metric tons used in final products in 1992, 31.6 thousand metric tons were imported, at a value of $7.2 million dollars (not shown in table). World production in 1992 was an estimated 3.1 million metric tons [Bureau of Mines, 1993, Table 1].

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Footnote(2) According to the Bureau of Mines, 1991 apparent consumption of asbestos in the United States was 34,765 metric tons [Bureau of Mines, 1993, Table 1]. Total consumption shown in table 1, taken from another Bureau of Mines table, differs from the first estimate by roughly 800 metric tons. The difference may be partly accounted for by the exclusion of the "Other" category from 1991 total in Table 1.

In July 1989, the Environmental Protection Agency issued a final rule under section 6 of the Toxic Substances Control Act to prohibit the future manufacture, importation, processing, and distribution of asbestos in almost all products. The Asbestos Ban and Phaseout Rule (40 CFR 763.160) was scheduled to eliminate asbestos in most commercial products in three stages over seven years beginning in 1990 and ending in 1996. EPA's asbestos rule was challenged in U.S. court by the asbestos industry. In October 1991, the U.S. Fifth Circuit Court of Appeals vacated and remanded most of the ban and phaseout rule to EPA. As a result of the Court decision, most asbestos products are no longer subject to the ban and phaseout rule. The Court chose to let stand EPA's authority to ban products that no longer are being produced in or imported into the United States.

Consumption of asbestos products in the United States has declined in recent years due to technological, regulatory and economic factors. U.S. manufacturers have modified product design to either (1) accommodate the use of asbestos substitutes or (2) eliminate the need for fibrous materials altogether. Examples of asbestos substitutes include aramid fiber, carbon fiber, cellulose fiber, ceramic fiber, fibrous glass, organic fiber, steel fibers, and wollastonite. The following products have been successfully introduced as alternatives to asbestos: aluminum, vinyl and wood siding; aluminum and fiberglass sheet; asphalt coatings; ductile iron pipe; polyvinylchloride pipe; prestressed and reinforced concrete pipe; and semimetallic brakes. Although the introduction of asbestos substitutes and alternatives enables manufacturers to avoid contact with asbestos, many of these surrogates pose occupational health hazards of varying degrees.

Despite the decline in U.S. consumption of asbestos, foreign markets continue to demand U.S. asbestos products. The export and re-export of asbestos fibers and asbestos products from the United States was valued at $140.8 million in 1992, an increase of 14 percent from the 1991 level. Leading importers of American asbestos materials were Canada, Japan, Mexico, the United Kingdom, and Germany. At the same time, three members of the European Community -- Germany, the Netherlands, and Italy -- are taking legislative steps to ban the use of asbestos. Effective dates for the ban initiatives ranged from July 1993 to 1995. In addition, Finland and Poland are phasing out the importation and use of asbestos [Canadian Mineral Yearbook, 1993, p. 10.4].

Asbestos Exposure in General Industry

OSHA has determined that the following general industry groups will be affected by the revision to the asbestos standard: primary manufacture of asbestos friction materials (SIC 3292); primary manufacture of asbestos gaskets and packings (SIC 3053); primary manufacture of asbestos adhesives, sealants, and coatings (SIC 2952); primary manufacture of asbestos-reinforced plastics (SIC 3089); general automotive repair (SICs 551, 554 and 753) and shipbuilding and repair (SIC 3731).

In addition, secondary gaskets and packings and secondary auto remanufacturing fall under the scope of the revised standard. However, few impacts, if any, are anticipated for these industry groups due to their low current exposure levels (below the revised PEL of 0.1 f/cc).

"Primary Manufacturing." Primary manufacturers use asbestos fiber as a raw material in the production of an intermediate product to be further processed or fabricated into a finished product. As shown in Table 2, two processes -- fiber introduction and product finishing/dry mechanical -- are common to all primary manufacturing operations and, according to risk profiles in earlier reports [RTI, 1985; ICF, 1988], have a high potential for generating airborne asbestos fiber.

Table 2. -- Estimated Population at Risk From Occupational
Exposure to Asbestos Repair, and Ship Repair

[By industry/process]
Sector Process group Number of affected establishments Number of workers exposed Number of full-time- equivalent exposed workers(a)
General Industry
Primary manufacturing: Friction materials All 25 1,415 1,415
Introduction 323 323
Wet Mechanical 390 390
Dry Mechanical 389 389
Other 314 313
Gaskets and packings All 9 168 168
Introduction 63 63
Wet Mechanical 23 23
Dry Mechanical 39 39
Other 43 43
Coatings and sealants All 75 1,181 1,181
Introduction 803 803
Other 378 378
Plastics All 1 18 18
Introduction 4 4
Wet Mechanical 1 1
Dry Mechanical 2 2
Other 11 11
Secondary manufacturing:
Gaskets and packings Dry Mechanical 71 2,142 2,142
Auto remanufacturing.Services: Dry Mechanical 62 1,761 1,761
Automotive repair Dry Mechanical 329,000 676,000 126,750
Shipyards
Ship repair All 18 985 241
Wet Removal/
Repair 788 193
Dry Removal/
Repair 197 48
Total 329,261 683,670 133,676
Sources: U.S. Dept. of Labor, OSHA, Office of Regulatory Analysis, based on CONSAD, 1990, and OSHA, 1994
Footnote(a) Totals in this column show the number of full-time-equivalent workers exposed to asbestos at any level

"Friction materials." Asbestos friction products include brake linings (i.e. linings for drum brakes, disc pads for disc brakes, and brake blocks), clutch facings, and industrial linings for equipment and appliances. Based on EPA survey data [ICF, 1988] and discussion with industry experts, OSHA and CONSAD estimate that 25 plants, employing a total of 1,415 workers, currently manufacture primary friction materials [CONSAD, 1990; OSHA, 1994].

"Gaskets and packings." Asbestos gaskets are used in static situations to avoid leakage, whereas asbestos packings are used in dynamic applications, such as pumps and valves, to control leakage where motion takes place. According to OSHA and CONSAD's profile of the industry, 130 production workers in 7 establishments are exposed to asbestos.

"Coatings and sealants." Asbestos fiber is used as a filler and reinforcer in asphalt and tar-based surface coatings. These products are then used as roof sealants, waterproofing coatings, automobile undercoatings, protective coatings for underground pipelines, anti-condensation coatings for low-temperature refrigeration services and fireproofing for structural steel. OSHA estimates that 1,181 production workers in 75 coatings and sealants plants are affected by the revised standard.

"Primary manufacture of plastics." Asbestos-reinforced plastic molding compounds are used in the electronic, automotive, and printing industries. Primary manufacturers of asbestos-reinforced plastics produce molding compounds in pellet or flake form. These plastics are used in commutators and rotors in electrical and automotive applications. Based on OSHA and CONSAD's industry profile [CONSAD, 1990; OSHA, 1994], OSHA projects that one plastics plant, employing eighteen workers, will be affected by the revised standard.

"Automotive repair." The general automotive repair and service sector includes establishments involved in brake and clutch repair work and maintenance. The major source of asbestos exposure in this sector occurs when compressed air is used for blowing the residual dust from the brake lining assembly. In addition, minor exposures in brake repair can occur during spray applications and when handling cloths and other supplies contaminated with asbestos fibers. Replacement of clutch assemblies can also lead to fiber release. CONSAD estimates that approximately 329,000 automobile repair shops and garages, brake and clutch repair establishments, and motor vehicle dealers, employing 676,000 workers, will be affected by the revision to the asbestos standard. OSHA is mandating specific engineering controls and work practices that will affect this sector.

"Shipbuilding and repairing -- historical contact with asbestos in shipyard work." The revision to the shipyard asbestos standard affects the shipbuilding and repairing industry, SIC 3731. Shipbuilding and repairing is a large-scale manufacturing activity that requires both skilled and unskilled labor. Shipyard work can be categorized into three main operations: (1) ship construction, (2) ship repair, and (3) ship overhaul. Asbestos exposure occurs during those conversion, repair, or overhaul operations where asbestos-containing components are removed or repaired.

Asbestos products were used extensively on American ships from the early 1940s through the late 1970s in joiner bulkhead systems in living space; for insulation of steam and hot water pipes, boilers, and tanks in machinery space; in ceiling tile; and in fire-resistant sheets in bulkheads [RTI, 1985]. However, after 1973, new specifications reduced the use of asbestos on ships regulated by the Maritime Administration (MARAD). Use of asbestos was only permitted in insulation cement in lagging for machinery casings and in lagging cloth.

Since 1978, specifications for government-subsidized ships have required the elimination of all asbestos lagging and insulation materials. Therefore, current ship building activities ordinarily do not generate any worker exposure to asbestos. However, OSHA believes that all ships delivered before 1975 contain extensive asbestos insulation materials, and that ships delivered between 1975 and 1978 contain asbestos in the form of insulating cement on machinery casings. Potential asbestos exposures occur when workers contact these materials during maintenance and repair activities [OSHA, 1986].

"Occupational exposure to asbestos." The greatest potential for occupational exposure to asbestos occurs during removal activities due to sawing, tearing, cutting, and scraping operations. Additional sources of asbestos exposure, involving a small number of shipyard workers, occur during repair activities such as removal and installation of gaskets [OSHA, 1986]. Whenever possible, asbestos is thoroughly wetted during removal activities. However, wet removal in nuclear reactor compartments is not permitted because of possible radiation contamination.

Shipyards are owned by both the private sector and the U.S. Navy. Private sector shipyards can be classified into three categories: (1) major shipyards engaged in construction and/or repair with drydocking facilities; (2) smaller "second-tier" shipyards that service inland waterways and coastal commerce and that build and repair smaller vessels; and (3) "topside" repair facilities that work on ships while they remain in the water.

The number of reported firms in SIC 3731, Ship Building and Repairing, has differed in recent years among traditional data sources. Many "firms" classified within the industry are very small, perform shipyard work only intermittently, or are marginal firms with short tenure. The 1987 Census of Manufactures included 590 shipyards (287 with twenty or more employees) operated by 547 companies [Dept. of Commerce, 1990a]. The Commerce Department's 1993 Industrial Outlook estimates a total of 585 establishments [U.S. Industrial Outlook, 1993]. However, in 1987, the Commission on Merchant Marine and Defense reported the existence of only 305 "working" shipyards [Merchant Marine Commission, 1987]. In their 1991 Report on Survey of U.S. Shipbuilding and Repair Facilities, the Maritime Administration reported that "over 200 privately-owned firms are involved in repairing ships in the United States" [Dept. of Transportation, 1991]. In addition to the private-sector shipyards, there are currently eight Navy-owned shipyards and two Navy-owned ship repair facilities [U.S. Industrial Outlook, 1993].

Employment in the shipbuilding and repair industry -- as high as 184,000 in 1981 -- was 118,000 in October 1992 according to the Bureau of Labor Statistics [BLS, 1993]. Employment has also declined in government-owned shipyards. In 1990 the five largest firms employed 81,000 workers while the 12 largest firms (all with at least 1,000 workers) employed 98,000 workers [Dept. of Transportation, 1990].

The largest percentage of asbestos work is performed in major shipyards [OSHA, 1991 (Ocken, p. 395)]. OSHA and CONSAD identified a range of 13 to 23 major shipyards as potentially affected by the revision to the asbestos standard [OSHA, 1994]. These establishments employ approximately 74,000 to 80,500 workers, of which an estimated three percent, or 2,220 to 2,415 workers, perform maintenance and repair activities [RTI, 1985; OSHA, 1994].

As shown in Table 2, OSHA analyzed impacts in two areas of ship repair:

wet removal/repair and dry removal/repair. Dry removal and repair occur in ship compartments, such as in nuclear powered vessels, where wet methods are infeasible. Based on OSHA and CONSAD's profile of the ship repair industry, OSHA estimates that 18 shipyards, employing 985 workers, are affected by the revised standard.

"Market conditions in the shipbuilding industry." During the 1980s, the shipbuilding industry experienced a sharp decline in output due to (1) competition from subsidized foreign shipbuilders; (2) decreased demand for new ships caused by excess supply; (3) the elimination of some subsidies for U.S. shipbuilders; and (4) a relaxation of the requirements for foreign ships entering the U.S. commercial fleet. No commercial ships were built in the United States between 1985 and 1990, and only four have been built or under construction since 1990. However, due to the requirements of the Jones Act, American shipyards still build all vessels used in domestic commerce -- smaller ships, barges, and tugboats. Industry forecasts also predict that the demand for commercial ships will "increase significantly" during the 1990s due to the need for replacement of an aging world merchant fleet [U.S. Industrial Outlook, 1993]. It remains to be seen what fraction of this business may be won by U.S. shipbuilders.

In contrast to the declining market for commercial ship construction, the market for ship repair and conversion work is strong. The U.S. Industrial Outlook reports that "the demand for some ship repair services * * * exceeds what is currently available in certain areas." In addition, investments by U.S. shipyards to improve, expand, and modernize repairing facilities are proceeding. Investment in fiscal year 1992 was $215 million, contrasted with $176 million for purchases of plant, machinery and equipment in 1991 [U.S. Industrial Outlook, 1993].

Asbestos in Construction

The construction industry is the principal market for asbestos materials and products in the United States, accounting for 68 percent of the asbestos consumed in 1992 [Bureau of Mines, 1993]. Asbestos products used in construction include asbestos-cement pipe, asbestos-cement sheet, coatings, compounds, packings, and roofing products.

With the decline in consumption of raw asbestos in U.S. manufacturing coupled with the introduction of asbestos substitutes into product design, the asbestos construction industry has shifted away from activities associated with installing asbestos products. Instead, in the last decade concern over the public risk presented by damaged asbestos in place, as well as the practical need to maintain aging interior sections in commercial and residential buildings, has directed the asbestos construction industry to the areas of demolition, removal, and renovation. In addition, custodial personnel occasionally come into contact with asbestos during their housekeeping duties.

The construction industry is comprised of a large number of firms:

approximately 536,300 establishments in 1987, employing just over 5 million workers [Dept. of Commerce, 1990b]. Of this industry total, 423,500 establishments, or 79 percent, employed fewer than 10 workers, while only 9.3 percent had 20 or more employees. The prevalence of small firms is partially related to the ease of entry into the construction industry. To establish a construction firm generally requires minimal capitalization; many firms, in fact, achieve success by carrying little overhead and adapting their services to industry trends. Furthermore, a sizable share of proprietorships in the industry are composed of self-employed individuals who contract their own services, and who shift back and forth from employee status to self-employment status as opportunities change.

In construction, unlike manufacturing, the typical industry end-product is highly differentiated and is produced at a site selected by the purchaser. Due to this degree of product specificity, each worksite usually has its own pattern of material use, building methods, and number and mix of workers. Thus, considerable variation may exist in actual worker use of, or contact with, asbestos materials and products. Although the occasional use of asbestos products appears to be the norm -- particularly given the changing material use patterns in new construction -- some workers (e.g. asbestos pipe installers and abatement/removal specialists) continually come into contact with asbestos materials and products.

Worker mobility, resulting in considerable shifting among both job sites and employers is another characteristic of the industry. Workers tend to identify with their craft or occupation, not with their employer [Lange and Mills, 1979]. Cyclical changes in the economy and seasonal work patterns cause variability of job opportunities, with a large portion of workers frequently entering and exiting the industry. Collectively, these factors make it very difficult to estimate the total number of workers exposed to asbestos and the duration of their exposure.

Based upon profiles of the asbestos construction industry by OSHA and CONSAD [OSHA, 1994; CONSAD, 1990], OSHA in this final RIA has estimated the number of construction workers potentially exposed in the areas affected by the standard -- that is, where asbestos products are installed, replaced, removed, or managed in place. Affected construction activities are found within the following general sectors: new construction; abatement and demolition; building renovation and remodeling; routine maintenance; and custodial work. Table 3 presents OSHA's profile of the population at risk from occupational exposure to asbestos in construction. Below are descriptions of the construction activities categorized within the general sectors affected by OSHA's revised asbestos standard.

Table 3. -- Estimated Population at Risk From Occupational Exposure to
Asbestos During New Construction, Abatement, Renovation, Routine

Maintenance Work and Custodial Activities
Construction activity Annual number of workers potentially exposed (lower bound) Annual number of workers potentially exposed (upper bound) Annual full- time-equiva- lent per- son -- years of exposure (a)
New Construction 494 4,260 2,377
A/C Pipe Installation 224 2,100 1,162
A/C Sheet Installation 270 2,160 1,215
Asbestos Abatement and
Demolition
55,101 79,361 21,295
Asbestos Removal 44,491 66,476 16,518
Encapsulation 4,610 6,885 1,615
Demolition 6,000 6,000 3,163
Renovation/Remodeling 60,735 95,914 60,735
Drywall Renovation 51,300 51,300 51,300
Built-Up Roofing Removal 2,235 19,444 2,235
Removal of Flooring
Products 7,200 25,170 7,200
Routine Maintenance in
Public, Commercial and
Residential Buildings
128,867 740,237 25,771
Repair/Replace Ceiling Tiles 13,686 38,650 725
Repair/Adjust HVAC/Lighting 39,434 60,793 2,091
Other Work Above Drop Ceilings 4,847 5,636 299
Repair Boiler 7,218 180,984 1,126
Repair Plumbing 7,218 180,984 1,126
Repair Roofing 24,040 127,621 2,404
Repair Drywall 3,576 80,231 3,576
Repair Flooring 28,848 65,338 14,424
Routine Maintenance in
Industrial Facilities
243,454 631,046 2,711
Remove/Install Gaskets, Small Scale 58,122 61,623 378
Remove/Install Gaskets, Large Scale 11,083 109,662 211
Remove/Repair Boiler Insulation, Small 22,204 26,172 169
Remove/Repair Boiler Insulation, Large 4,156 48,827 79
Remove/Repair Pipe Insulation, Small 22,204 26,172 169
Remove/Repair Pipe Insulation, Large 4,156 48,827 79
Miscellaneous Maintenance, Small 44,593 49,957 312
Miscellaneous Maintenance, Large 8,312 89,974 158
Miscel. Telecommunications Maintenance, Small 32,544 48,240 354
Miscel. Telecommunications Maintenance, Large 36,080 121,592 802
Custodial Work in Public, Commercial and Residential Buildings: Sweeping, cleaning, dusting activities 1,126,000 3,665,000 223,160
Custodial Work in Industrial Facilities: Sweeping, cleaning, dusting activities 143,355 535,768 31,442
Total 1,758,006 5,751,586 367,491
Sources: U.S. Dept. of Labor, OSHA, Office of Regulatory Analysis,based on OSHA, 1986, and OSHA, 1994
Footnote(a) Totals in this column show the number of full-time-equivalent workers exposed to asbestos at any level

"New construction." New construction activities account for the bulk of asbestos materials and products consumed in a typical year. Major products include asbestos-cement pipe, asbestos-cement sheet, coatings and compounds, and roofing products. As depicted in Table 1, these construction products comprised over half (19 thousand metric tons) of the total U.S. asbestos consumption in 1992.(3)

__________

Footnote(3) Total consumption of asbestos-cement sheet was approximated as 50 metric tons for the purpose of this calculation.

"Asbestos-cement pipe." Asbestos-cement pipe (A/C pipe) is used chiefly for transporting drinking water in a pressurized condition and to provide drainage for storm water, sewage and other liquid waste. Approximately 90 percent of A/C pipe purchases are of pressure water pipe [AIA, Ex. 117, 1991]. A/C pipe is also used in industrial applications, to carry gaseous products, and as an electrical conduit for heating, cooling and gas venting [ICF, 1988].

Use of A/C pipe in the United States is concentrated in the Mountain, Pacific and Southwest regions. In 1991, the Asbestos Information Association commented [Ex. 117] that "pre-cut, pre-tapped pipe has received tremendous marketplace acceptance and represents a large majority of sales." This is significant because the use of pre-cut, pre-tapped pipe may reduce or eliminate some types of field fabrication activities.

A/C pipe is composed of 15-25 percent asbestos, 42-53 percent Portland cement, and 34-40 percent ground silica sand. The use of raw asbestos in the production of A/C pipe fluctuated somewhat but remained fairly constant during the mid-1980s (26,100 metric tons in 1983, 37,000 metric tons in 1984, 32,691 metric tons in 1985) [ICF, 1988] but has declined dramatically since: 7,900 metric tons in 1989, 1,700 metric tons in 1992 [Bureau of Mines, 1993]. The use of substitutes for asbestos and the overall slump in new construction in the early 1990s probably account for much of the decline in asbestos consumption in A/C pipe. Based on OSHA and CONSAD's profile of the industry, OSHA estimates that 224 to 2,100 workers, or an average of 1,162 workers, are exposed to asbestos during installation of A/C pipe.

"Asbestos-cement sheet." Asbestos-cement sheet (A/C sheet) has a variety of uses as a structural, technical and decorative material in large residential buildings, electrical utilities, industrial plants, schools, and hospitals. A/C sheet includes flat sheet, corrugated sheet, and roofing and side shingles. Of these four main types of A/C sheet, all, as of the date of ICF's market survey, were produced in the United States with the exception of corrugated sheet [ICF, 1988]. According to ICF, flat A/C sheet has the following principal applications:

* Wall lining in factories and agricultural buildings * Fire-resistant walls * Curtain walls * Industrial partitions * Soffit material (covering the underside of structural components * Interior and exterior decorative paneling. Specialized applications of flat A/C sheet include its use in cooling towers, as laboratory table tops and fume hoods, and as a component of vaults, ovens, safes, heaters, and boilers.

Asbestos-cement shingles are used as siding and roofing for residential and commercial buildings. According to results from ICF's market survey, demand for roofing shingles represents 70 percent of consumption in the A/C shingle market while demand for siding shingles constitute the remainder of the market.

A/C sheet may contain anywhere from 15 to 40 percent asbestos, in combination with cement and, occasionally, silica [Cogley, et al., 1982]. In recent years, manufacturers have substituted other materials for asbestos in the production of A/C sheet; meanwhile, due to unit price differences, alternative construction components such as pre-cast concrete and cement/wood board have replaced A/C sheet in the building industry [OSHA, 1986]. Together, these factors have contributed to a decline in asbestos consumption in the A/C sheet market from levels of roughly 11,000 metric tons of raw asbestos in the early 1980s [OSHA, 1986] to a 1992 consumption of under 100 metric tons (see Table 1). OSHA estimates that, the population at risk during A/C sheet installation ranges from 270 to 2,160 workers, or an average of 1,215 employees.

"Asbestos abatement and demolition." Increased health concerns regarding the potential release of asbestos fibers have prompted a desire to remove or encapsulate such materials in existing buildings. In response to this demand, a variety of specialty contractors and construction trades have become active in asbestos abatement, particularly in schools, where EPA regulations have indirectly generated a large market for this type of service.

The asbestos abatement industry experienced extraordinary growth in the 1980s due to legal, regulatory, economic and health-related factors. Rifkin-Wernick Associates [Rifkin-Wernick, 1990], specialists in analyzing the asbestos industry, estimate that combined public and private building ownership spent $4.2 billion in 1989 for services and products related to asbestos abatement in their properties. This level of abatement expenditures represented an increase of 24 percent over levels in 1988. According to Rifkin-Wernick, asbestos construction activities associated with demolition, renovation, and operations and maintenance accounted for around 90 percent of abatement expenditures; the remainder of abatement expenditures satisfied legal or economic considerations while addressing lower-level safety concerns.

Rifkin-Wernick reports that approximately 50 percent of asbestos abatement business in 1989 occurred in eight states: California, New York, Texas, Pennsylvania, Illinois, Ohio, Florida and Michigan. Of the $4.2 billion in abatement expenditures in 1989, commercial buildings (offices, retail establishments, hotels/motels and warehouses) accounted for $1.4 billion in abatement services. Industrial buildings accounted for nearly $1 billion in asbestos abatement expenditures, while abatement in schools totaled $800 million, or roughly one-fifth of the industry.

In early 1990, 2,100 asbestos abatement contractors operated in the United States under either state certification or some other license. Rifkin-Wernick estimates that abatement contractors in 1989 employed 161,000 workers, of which 98,000 were full-time. Firm size in the industry was generally small: 80 percent of contractors employ fewer than 50 people and over half of asbestos contractors have no part-time employees.

Contractor revenues in 1989 totaled $3.6 billion. Rifkin-Wernick classified contractors by revenue size and geographic radius of operation. National contractors are defined as conducting business beyond 1,000 miles of headquarters and with revenues above $20 million. Regional contractors, in Rifkin-Wernick's classification system, tend to operate 250 to 1,000 miles from the main office and earn revenues of $5 million to $20 million. Finally, local contractors operate primarily within a 250-mile radius of home and earn under $5 million. Table 4 presents Rifkin-Wernick's 1990 assessment of contractor market concentration for two earlier years and market projection for 1994.

Table 4. -- Market Concentration

[1987-1994]
1987 1989 1994
(projected)
Number of Contractors:
  • National
8 20 15
  • Regional
100 200 150
  • Local
1,200 1,872 500
    • Total
1,308 2,092 665
Revenues ($ Million):
  • National
$155 $832 $1,050
  • Regional
362 1,720 2,250
  • Local
517 1,086 470
    • Total
1,034 3,638 3,770
Market Share (%)
  • National
15% 23% 28%
  • Regional
35% 47% 60%
  • Local
50% 30% 12%
    • Total
100% 100% 100%
Revenues Per Contractor ($ Million):
  • National
$19.3 $41.6 $70.0
  • Regional
3.6 8.6 15.0
  • Local
0.4 0.6 0.9
    • Total
0.8 1.7 5.7
  • Source: Rifkin-Wernick, 1990

In developing its profile of the abatement and demolition industry, OSHA [OSHA, 1994], recognized the growth in market specialization observed by Rifkin-Wernick and other experts. Therefore, OSHA applied lower-bound worker population estimates to the cost and benefit analysis. For all of abatement and demolition, OSHA estimates a full-time workforce of 21,295 persons.(4)

__________

Footnote(4) OSHA notes that its estimate for the number of full-time abatement workers is lower than Rifkin-Wernick's 1989 estimate. OSHA believes that this discrepancy may possibly be due to three factors: 1) the cyclical decline in the industry during the recession of 1990-1991 and subsequent slow recovery; 2) increased specialization among abatement workers and the adoption of labor-saving technologies and work practices; and 3) the inclusion of abatement workers in other activity groups within OSHA's industry profile.

"Renovation and remodeling." The principal general renovation activities that entail occupational exposure to asbestos are: the demolition of drywall (including removal of transite panels), the removal of built-up roofing containing asbestos roofing felts, and the removal of asbestos flooring products. OSHA and CONSAD [OSHA, 1994] estimate that anywhere from 60,735 to 95,914 workers -- all of whom are full-time professionals -- may be at risk from asbestos exposure during renovation and remodeling. OSHA believes that specialization has emerged in the industry to the extent that a lower-bound estimate of the workforce is appropriate in this impact analysis. Consequently, OSHA estimates that 60,735 full-time-equivalent workers in renovation and remodeling of asbestos-containing buildings are affected by the revised standard.

"Drywall demolition." The occupational exposure to asbestos associated with the demolition and renovation of drywall results primarily from the release of asbestos fibers from the spackling, tape, and joint compounds used to produce a smooth surface across the entire wall. Although the use of asbestos in drywall tape and spackling compound is now prohibited, asbestos-containing finishing materials were routinely used in drywall application through the early 1970s. Thus, the demolition and renovation of drywall in any building constructed prior to the mid-1970s is likely to expose workers to friable asbestos.

On occasion, drywall renovation involves contact with sprayed- and troweled-on fireproofing and other asbestos surfacing material. Information on the frequency of contact with high-risk asbestos-containing material during drywall renovation is limited but suggests that a minor percentage of projects are affected [CONSAD, 1985]. OSHA estimates that 20 percent of drywall renovations involve contact with high-risk ACM. A breakdown of the worker population for drywall renovation is given below under BENEFITS.

"Built-up roofing removal." Built up roofs constructed with asbestos roofing felts generally have long useful lives of 20 or more years. CONSAD [CONSAD, 1990] used Bureau of Mines data on production of roofing felt in the 1960s to estimate that approximately 80,000 tons of asbestos-containing roofing products will be removed annually.

"Removal of asbestos flooring products." Asbestos flooring products, also termed "resilient floor coverings," include vinyl/asbestos floor tile, asphalt/asbestos floor tile, and sheet flooring backed with asbestos felt. Asbestos flooring products are estimated to be in over 3.6 million buildings [EPA, 1984]. Although these floors have a useful life of approximately 25-30 years, they are generally replaced more often [RFCI, 1990].

"Routine maintenance in public, commercial and residential buildings."

Routine building maintenance activities can involve exposure to asbestos because of the presence of products containing asbestos. Worker exposure can be a result of direct contact with the asbestos materials and products or can result from disturbance of settled dust in the vicinity of asbestos-containing materials (for example, when work above a drop ceiling is performed where asbestos-containing insulation or fireproofing was used). Maintenance activities that can involve asbestos exposure include: adjustment or repair of HVAC ductwork or lighting (above a drop ceiling); replacement of drop ceiling tiles; repair of leaking water or steam pipes; boiler maintenance or repair activities; and repairs to roofing, drywall or flooring. Workers at risk during these activities include in-house building maintenance personnel, contract maintenance crews, and special trades contractors. Based on an industry profile by CONSAD [CONSAD, 1990], OSHA estimates that anywhere from 128,867 workers to 740,237 workers are potentially exposed while performing routine maintenance activities in public, commercial and residential buildings.

For this economic impact analysis, OSHA assumed that owners of affected buildings will minimize compliance costs by applying maintenance personnel -- whether in-house or contract -- to asbestos projects on a full-time basis, where possible. Under this assumption, the absolute number of affected workers would equal the lower-bound estimate for the population at risk (128,867 workers). In terms of person-years of exposure (number of persons exposed over a year of eight-hour days), the lower-bound population at risk equates to 25,771 full-time-equivalent persons, as shown in Column 3 in Table 3.

Renovation, maintenance, and repair operations comprise a significant portion of total construction activity. In 1987, receipts from maintenance and repair operations alone were $50.4 billion, or 10 percent of total construction receipts [Dept. of Commerce, 1990b].

"Routine maintenance in industrial facilities." In general industry, routine maintenance and repair can involve the disturbance of asbestos- containing materials and products (ACM), including such products as gaskets, pipe and boiler insulation, electronic components and structural building materials. Asbestos industrial materials and products are most widely used in (1) the manufacture of malt beverages, paper products, chemicals, petroleum products, glass and ceramics, iron and steel, and fabricated metal products; (2) telephone communications; (3) electric utilities; and (4) other public utilities (gas, water, sanitary services). Occupational exposure to asbestos fibers can occur among maintenance workers directly involved in disturbance of ACM as well as among production workers near the maintenance work site.

For this final analysis of the costs and benefits of the revised asbestos standard, OSHA identified five general types of routine maintenance in industrial facilities, listed below.

* Gasket removal and installation

* Boiler removal and installation

* Pipe removal and installation

* Miscellaneous maintenance

* Miscellaneous telecommunications maintenance

Miscellaneous maintenance includes the variety of building maintenance (ceiling work, roofing, drywall, etc.) described above under "Routine Maintenance in Public, Commercial, and Residential Buildings." Miscellaneous telecommunications maintenance includes 1) removal of electronic components, particularly line card resistors, insulated with asbestos and 2) placement or removal of communications wire and cable.

Table 3 presents the range of workers in general industry potentially exposed to asbestos during routine maintenance tasks. In this impact analysis, OSHA assumes that, to minimize compliance costs, affected establishments will concentrate asbestos maintenance duties among a group of trained specialists. Shown in Column 3 in the table are OSHA's estimates for full-time populations at risk for each maintenance activity. For all of general industry, a total of 2,711 full-time-equivalent persons perform construction-related duties.

"Custodial work in public, commercial and residential buildings."

Asbestos exposure in public and commercial buildings can occur during a variety of tasks involving disturbance of asbestos or asbestos-containing materials, in addition to routine maintenance activities described above. Custodial work in buildings with ACM can include any of the following types of activities: sweeping; cleaning; dusting; mopping; vacuuming; stripping and buffing of vinyl-asbestos floor tile; and clean-up after asbestos removal or other significant asbestos construction work.

A recent EPA-sponsored study of asbestos exposure among custodial workers in Missouri reports frequency and duration of custodial activities [Wickman, et al., 1992]. Modeling a custodial worker profile on the Missouri study and on building survey data from EPA, OSHA and CONSAD estimated the range of workers potentially at risk [OSHA, 1994]. OSHA estimates that anywhere from 1.1 million to 3.7 million workers are at risk from asbestos exposure during custodial work.

OSHA believes that there is presently little specialization in asbestos custodial work and that the actual number of workers at risk approximates the average of the lower-bound and upper-bound number of workers. In terms of person-years of exposure over work weeks consisting of eight-hour days, OSHA estimates that 223,160 full-time-equivalent workers are at risk during custodial disturbance of asbestos or asbestos-containing materials.

"Custodial work in industrial facilities." Custodial work in industrial facilities largely resembles custodial work in public, commercial, and residential buildings and was identically modeled by CONSAD. The workforce at risk performing custodial activities in industrial facilities ranges from 143,355 to 535,768 workers, as shown in Table 3. Taking the average of this range and calculating the full-time-equivalent population, OSHA estimates that 31,442 person-years of exposure occur in general industry annually during custodial work.

C. Assessment of Regulatory and Non-Regulatory Alternatives Introduction

The declared purpose of the Occupational Safety and Health (OSH) Act of 1970 is "* * * to assure so far as possible every working man and woman in the Nation safe and healthful working conditions and to preserve our human resources * * *" Thus, the Act requires the Secretary of Labor, when promulgating occupational safety and health standards for toxic materials or harmful physical agents, to set the standard " * * * that most adequately assures, to the extent feasible, on the basis of the best available evidence, that no employee will suffer material impairment of health or functional capacity * * *" On the basis of this congressional directive, OSHA has responded to the Court of Appeals by issuing a final revision to the asbestos standard, the intent of which is to further reduce the adverse health effects associated with occupational exposure to asbestos. This chapter reviews regulatory and non-regulatory alternatives that OSHA considered and found to be inadequate for full remediation of the occupational hazards of asbestos.

Private Markets and Occupational Health

Economic theory suggests that the need for government regulation is greatly reduced where private markets work efficiently and effectively to allocate health and safety resources. The theory typically assumes perfectly competitive labor markets where workers, having perfect knowledge of job risks and being perfectly mobile among jobs, command wage premiums that fully compensate for any risk of future harm. Thus, theoretically, the costs of occupational injury and illness are borne initially by the firms responsible for the hazardous workplace conditions and, ultimately, by the consumers who pay higher prices for the final goods and services produced by these firms. With all costs internalized, private employers have an incentive to reduce hazards wherever the cost of hazard abatement is less than the cost of the expected injury or illness. The resultant level of safety and health is considered "efficient" in the sense that it minimizes the sum of the costs of hazard prevention and of injury or illness. Perfectly competitive labor markets, however, do not exist for many industrial markets. OSHA, therefore, believes that it must take appropriate actions to provide greater worker protection against exposures to toxic substances.

Evidence indicates that market forces have not been effective in reducing excessive occupational exposure to asbestos, thereby contributing to the development of diseases related to it. In spite of the hazards associated with asbestos, the social costs of production have not been internalized, in part because of market imperfections and the existence of externalities. Consequently, the amount of protection that the private market will offer to workers differs from the socially desired level, for the following reasons.

First, evidence on occupational health hazards in general suggests that, in the absence of immediate or clear-cut danger, employees and employers have little incentive to seek or provide information on the potential long-term effects of exposure. When relevant information is provided, however, employers and employees might still find informed decision making a difficult task, especially where long latency periods precede the development of disease. Moreover, if signs and symptoms are nonspecific -- that is, if an illness could be job-related or could have other causes -- employees and employers may not link disease with exposure.

Second, even if workers were fully informed of the health risks associated with exposure to asbestos, many face limited employment options. Non-transferability of occupational skills and high regional unemployment rates sharply reduce a worker's expectation of obtaining alternative employment quickly or easily. A worker employed in resurfacing automobile brakes, for example, could find it difficult to apply occupational skills to a new job in searching for a safer workplace. In many regions of the country, the practical choice for workers is not between a safe job and a better paying but more hazardous position, but simply between employment and unemployment at the prevailing rates of pay and risk. In addition to the fear of substantial income loss from prolonged periods of unemployment, the high costs of relocation, the reluctance to break family and community ties, and the growth of institutional factors such as pension plans and seniority rights serve to elevate the cost of job transfer.

In addition to the market imperfections, externalities result in employers and employees settling for an inefficiently low level of protection from toxic substances. For the competitive market to function efficiently, only workers and their employers should be affected by the level of safety and health provided in market transactions. In the case of occupational safety and health, however, society shares part of the financial burden of occupationally induced diseases, including the costs of premature death, excess sickness, and disability. Individuals who suffer from occupationally related illness are cared for and compensated by society through taxpayer support of social programs, including welfare, Social Security, and Medicare. These combined factors of labor market imperfections and the existence of externalities prevent the market from delivering an optimal supply of healthful working conditions in industries where asbestos hazards exist.

Tort Liability and Asbestos Litigation

Greater reliance on the use of liability under tort law is one of the examples of a non-regulatory alternative identified and set forth by the Office of Management and Budget guidelines for implementing Executive Orders 12866 and 12291. Prosser [Prosser, 1971] describes a tort, in part, as a "civil wrong, other than a breach of contract, for which the court will provide a remedy in the form of an action for damages," although he says that "a really satisfactory definition has yet to be found."

If the tort system effectively applied, it would allow a worker whose health has been adversely affected by occupational exposure to asbestos to sue and recover damages from the employer. Furthermore, the tort system would shift the liability of direct costs of occupational disease from the worker to the firm under certain specific circumstances. The tort system has had limited success in shifting the cost of occupational disease. The limitations of the system are discussed in the following paragraphs.

Asbestos product liability litigation as a means of reducing worker exposure to asbestos has proven effective in some areas, but cumbersome to resolve. The difficulties are inherent in the litigation process as it relates to asbestos products and in the nature of the diseases associated with asbestos.

With very limited exceptions, however, the tort system is not a viable alternative in dealings between employees and their employers. All states have legislation providing that Workers' Compensation is either the exclusive or principal remedy available to employees against their employers. Thus, tort law can only be applied to third-party suppliers of a hazardous substance. It is often difficult, however, to demonstrate cause, which is a necessary prerequisite for the successful application of tort liability against these suppliers.

First, knowledge of the worker exposure must exist. The worker and/ or the physician must be aware of both the magnitude and duration of exposure to asbestos and the causal link between the disease and the occupational exposure. Furthermore, it could be extremely difficult to isolate the role of occupational exposures in causing the disease, especially if workers are exposed to many toxic substances. Second, the liable party must be identifiable, but workers may have several employers over a working lifetime. Third, the scientific and medical evidence available to support the contention that the disease was caused by job-related exposure must withstand judicial standards for proof of causality. This task is very difficult because of the long latency periods associated with asbestos-related diseases.

The costs associated with producing information and with litigation itself may be quite substantial. First, information is a public good, which means that once produced it can be transmitted inexpensively to any number of individuals without diminishing the quality or quantity of the information. It is, therefore, difficult to control distribution once the information is produced. A producer of information may find that information produced at great expense can be acquired freely by potential customers, and that, consequently, the market for the information has virtually disappeared. As a result, public goods are typically underproduced relative to what is considered economically efficient. This general undersupply of information adversely affects the workers' awareness of the cause of their illness and thus reduces the likelihood that they will pursue tort liability suits.

Second, legal proceedings impose costs on both plaintiffs and defendants. Victims of torts must incur legal fees associated with bringing about court action. In deciding whether to sue, the victim must be sure that the size of the claim will be large enough to cover legal expenses. In effect, the plaintiff is likely to face substantial transaction costs in the form of legal expenses. These are commonly set at a 33 percent contingency for the plaintiff's lawyer, plus legal expenses. The accused firm must also pay for its defense. A report prepared by the Research Triangle Institute [RTI, 1982], contains some data pertaining to legal costs and the size of awards. One investigator, for example, found that an average ratio of legal costs to proceeds was 37 percent for a sample of cases. The data, however, do not separate legal fees paid by the defendants and plaintiffs.

The majority of occupational disease tort activity has involved workers exposed to asbestos. These employees could avoid the exclusive remedy of Workers' Compensation by suing suppliers, whereas asbestos exposures are best controlled by employers.

In a consolidated class-action case in 1990, a Texas court awarded more than $3.5 million in compensatory damages to 2,366 workers who had been exposed to asbestos in refineries. Punitive damages were to be awarded on the basis of gross negligence on the part of the suppliers [Dallas Morning News, 1990].

In 1993, a settlement was reached in a lawsuit involving future personal injury claims against 20 asbestos product manufacturers represented by the Center for Claims Resolution (Carlough v. Amchem Products, Inc). It would provide $1 billion over the next ten years to settle about 100,000 claims as people exposed to the manufacturers' products contract asbestos-related conditions. Payments would depend on the type of condition and attorneys' fees would be capped at 25 percent of each payment [BNA, 1993]. The settlement was reached by parties aware of the decades-long impasses in asbestos litigation that have frustrated the tort liability process.

It is unusual for insurance and liability costs to be borne in full by the specific employer responsible for the risk involved. For firms using insurance, the premium determination process is such that premiums only partially reflect changes in risk associated with changes in asbestos or other hazardous exposures. This results in the so-called "moral hazard problem," which is the risk that arises from the possible dishonesty or imprudence of the insured. As the insured has paid for an insurance company to assume some of his or her risks, he or she has less reason to exercise the diligence necessary to avoid losses. This transfer of risk is a fundamental source of imperfection in markets.

For firms that self-insure or carry liability insurance with a large deductible, the costs of a single claim may be fully borne by the firm. Very small firms, and large firms with a large number of claims, however, may fail to meet the full costs by declaring bankruptcy, as has happened with Johns Manville and other former asbestos producers. The attempts at financial restructuring by defendants of asbestos litigation further reduce the chances that workers who contract asbestos-related diseases as employees of these companies or as employees of companies that used their products will collect compensation [Washington Post, 1990].

Workers' Compensation

The Workers' Compensation system came about as the result of perceived inadequacies in liability or insurance systems to compel employers to prevent occupational disease or compensate workers fully for their losses. This system was designed to internalize some of the social costs of production, but in reality it has fallen short of compensating workers adequately for occupationally related disease. Thus, society shares the burden of occupationally related adverse health effects, premature mortality, excess morbidity, and disability through taxpayer support of social programs such as welfare, Social Security disability payments, and Medicare.

Government Regulations and Rejected Alternative Standards

In order to compensate for market imperfections (some of which are detailed above), a number of federal and state regulations have been promulgated in the attempt to improve the allocation of resources. While some of these regulations may have a limiting effect on occupational exposures to asbestos, OSHA does not believe that these regulations obviate the need for an OSHA standard regulating occupational exposure to asbestos.

OSHA's current permissible exposure level (PEL) for asbestos of 0.2 fibers per cubic centimeter (f/cc) does not eliminate all significant risk to workers. Given the recent health evidence of carcinogenic and non-carcinogenic hazards, OSHA believes that to fully protect workers it is necessary to lower the asbestos PEL and establish ancillary provisions.

For public, commercial, residential and industrial buildings, OSHA rejected, on the basis of cost and feasibility considerations, alternative approaches requiring owners to conduct up-front inspections for asbestos-containing materials or to inspect before ACM is disturbed. These approaches have also been examined by the Environmental Protection Agency. An analysis by EPA's contractor [Abt, 1992] projected potential compliance costs of $13.2 billion to $16.2 billion for an up-front survey approach and potential costs of $3.2 billion to $14.5 billion for an identify-before-disturb option. OSHA's approach, instead, specifies parameters for making reasonable assumptions about the presence of asbestos-containing materials within building components and notifying and protecting maintenance workers, custodians and building occupants as prescribed elsewhere in the revised standard.

D. Benefits of the Revision to the Final Asbestos Standard Introduction

The inhalation of asbestos fiber has been clearly associated with three clinical conditions: asbestosis, mesothelioma (a cancer of the lining of the chest or abdomen), and lung cancer. Studies have also observed increased gastrointestinal cancer risk. Risk from cancer at other sites, such as the larynx, pharynx, and kidneys, is also suspected.

Initial exposure limits for asbestos were based on efforts to reduce asbestosis which was known to be associated with asbestos exposure. The reduction in cases of asbestosis, however, resulted in workers living long enough to develop cancers that are now recognized as associated with asbestos exposure. The following discussion of the benefits associated with a reduction in exposures, therefore, focuses on the number of cancer cases avoided within the exposed work force. The results are expressed in terms of deaths avoided because these cancers almost always result in death.

Methodology

OSHA calculated expected benefits following promulgation of the final revised asbestos standard for workers employed in the general industry, shipyards, and construction sectors. In this benefits analysis, the following types of preventable asbestos-related cancer mortalities were evaluated: (1) Preventable lung cancers, (2) preventable mesotheliomas, and (3) preventable gastrointestinal cancers. The risk assessment used to derive OSHA's estimate of the number of cancers prevented is discussed in Chapter 5 of the regulatory impact analysis of the 1986 final asbestos standard [OSHA, 1986]. For this analysis, OSHA updated the 1986 risk assessment to include 1991 data on the gender and age distribution within affected industry sectors [BLS, 1991] and the 1991 mortality rates associated with malignant neoplasms of respiratory and intrathoracic organs [NCHS, 1993].

The benefits of a reduction in the PEL depend upon current exposure levels, the number of workers exposed, and the risk associated with each exposure level. OSHA's estimates for current exposures, the number of full-time equivalent workers exposed, and the exposure levels after compliance with the revision to the final rule are presented in Table 5 for general industry and shipyards and Table 6 for construction.

Table 5. -- Estimated Occupational Exposure to Asbestos and
Reduction in Cancer Risk in General Industry and
Shipyards as a Result of the Final Revision
to the Standard
Sector Number of full- time- equiva- lent exposed workers Represen- tative exposure levels absent respira- tory protec- tion (f/cc) Current exposure level (f/cc) Level of exposure (f/cc) after final rule Reduction in cancer deaths
General Industry:
  • Primary Manufacturing:
  • Friction Materials
1,415 0.1419 0.0390 0.00651 0.0510
  • Gaskets and Packings
168 0.0999 0.0430 0.00718 0.0067
  • Coatings and Sealants
1,181 0.0970 0.0420 0.00701 0.0458
  • Plastics
18 0.0638 0.0540 0.00902 0.0009
Services:
  • Automotive Repair
126,750 0.017 0.0170 0.00294 1.9768
Shipyards:
  • Wet Removal/Repair
193 0.42 0.1162 0.00739 0.0244
  • Dry Removal/Repair
48 3.7 0.1889 0.01202 0.0099
    • Total
129,774 2.12
Source: U.S. Department of Labor, OSHA, Office of Regulatory Analysis, based on CONSAD, 1990, Table 3.2, OSHA 1986, Table V-1, and the rulemaking record

Table 6. -- Estimated Occupational Exposure to Asbestos and Reduction in
Cancer Risk In Construction As A Result Of The Final
Revision To The Standard

(For Table 6, see printed copy)

OSHA calculated annual preventable cancers associated with the revised standard through a five-step procedure. First, OSHA estimated baseline occupational exposure levels -- in terms of 8-hour time-weighted average fiber levels -- for all affected sectors using data from the record and from previous asbestos regulatory impact analyses. Then, applying the OSHA/Nicholson risk assessment model to baseline exposures and the associated populations at risk, OSHA calculated baseline cancers among affected workers. In the third step, OSHA estimated occupational exposure levels as a result of compliance with the final standard, using assigned protection factors for designated controls. OSHA then projected total residual cancers following promulgation of the standard. Finally, OSHA calculated the number of compliance-related preventable cancers by subtracting the number of residual cancers from the number of baseline cancers.

Occupational Exposure Profile

For each sector affected by the revised asbestos standard, OSHA assessed current occupational exposures using data from past regulatory impact analyses and the rulemaking records for this final standard and for previous OSHA asbestos standards. Principal sources of exposure data for this final RIA were Economic and Technological Profile Related to OSHA's Revised Permanent Asbestos Standard for the Construction Industry and Asbestos Removal and Routine Maintenance Projects in General Industry prepared by OSHA's contractor CONSAD Research Corporation [CONSAD, 1985]; Economic Analysis of the Proposed Revisions to the OSHA Asbestos Standards for Construction and General Industry, also by CONSAD [CONSAD, 1990]; OSHA's 1986 final asbestos regulatory impact analysis [OSHA, 1986]; and OSHA's regulatory analysis of the excursion limit [OSHA, 1988].

Average exposures and the range of exposures reported in CONSAD [CONSAD, 1985, 1990] and OSHA [1986] were developed from a review of the record for the rulemaking proceeding that led to promulgation of the current OSHA asbestos standard. Baseline exposures described in the literature and reported by CONSAD in 1985 generally reflected the use of minimal engineering controls and the virtual absence of respiratory protection. These baseline exposures were reported by OSHA in its 1986 RIA and served to establish baseline risk estimates for affected workers prior to compliance with the final standard promulgated in 1986. In its 1986 RIA, OSHA assumed that the controls implied by compliance with the 1986 standard would result in specified rates of effectiveness and would lead to benefits in preventable cancers.

In this final RIA for the revised asbestos standard, OSHA developed an exposure profile for affected occupational groups using representative data from the 1986 RIA, from CONSAD reports [1985, 1990] and from the rulemaking record. For each affected sector, OSHA estimated baseline exposures using the following assumptions: (1) Where reasonable and appropriate, engineering controls and work practices assigned in the 1986 RIA were assumed to be in current use; (2) where engineering controls and work practices were not sufficient to reduce maximum exposures to a PEL of 0.2 f/cc and an excursion level of 1.0 f/ cc, OSHA assumed that the least-cost respiratory protection would be applied. OSHA's baseline exposure profile for this revision to the asbestos standard thus reflects industry application of controls, work practices and respirators to achieve permissible limits established under the OSHA 1986 and 1988 rulemakings.

Table 5 presents average baseline exposure levels for general industry and shipyards and Table 6 presents average baseline exposure levels for construction. Tables 5 and 6, in addition, show average baseline exposure levels in the absence of respiratory protection and other primary controls and work practices (Column 2 in Table 5, Column 3 in Table 6), taken from representative data in the rulemaking record (see [CONSAD, 1985] and [CONSAD, 1984]). Also shown in Table 6 are representative exposure levels (Column 4) in the absence of respiratory protection. Fiber levels prior to respirator use were estimated by applying, to potential mean exposure levels (Column 3), protection factors for wet methods, glove bags and other controls judged currently in use, at hypothetical application levels of 100 percent.

Mean exposures in nearly all sectors are estimated to be at or below the current PEL and excursion limit, consistent with the assumptions in the 1986 RIA and 1988 excursion limit analysis of 100 percent compliance with the final standards. For most of the sectors presented in the tables, OSHA's estimated current exposure levels were determined by applying, to baseline exposures in the absence of controls, protection factors ranging from 10 to 1000, adjusted to reflect current application of controls. In that real-world application of engineering controls and work practices is under 100 percent in nearly all asbestos construction sectors, mean current exposure levels (Column 5) can exceed representative (hypothetical) fiber levels absent respirators (Column 4).

Also shown in Tables 5 and 6 are OSHA's estimated exposure levels following the final revision to the standard. OSHA projected exposure levels for each affected General Industry, Shipyards, and Construction activity by applying protection factors to average baseline exposures. OSHA calculated protection factors for each activity by assuming that controls have a multiplicative effect in reducing exposures, that is, the cumulative protection provided by a set of controls is the product of individual protection factors. OSHA assigned protection factors to all significant controls and calculated cumulative protection factors for all affected sectors. Cumulative protection factors were then applied to baseline exposures in order to determine exposures resulting from compliance with the final revised standard. As shown in Column 3 in Table 5 and in Column 5 in Table 6, projected exposures are quite low (some below the level of detection), commensurate with the high degree of protection provided by the controls required by, or, in some cases, implied by the revised standard.

Estimates of Cancers Prevented, by Industry

"Benefits to workers in direct contact with asbestos." Tables 5 and 6 present OSHA's estimated annual benefits to employees affected by the revised standard. Quantified benefits represent the total of avoided cases of death from lung cancers, mesothelioma, and gastrointestinal cancers. In general industry and shipyards, OSHA projects that wider use of engineering controls, work practices and respiratory protection will result in 2.1 avoided cancer deaths. In construction, expected benefits total 40.5 avoided cancers. Of these total avoided deaths resulting from compliance with the revised construction standard, 26.3 deaths will be avoided through protection of personnel directly exposed to asbestos-containing material. However, OSHA's analysis does not quantify benefits among those workers that may be secondarily exposed while present at sites where asbestos work is being done. Among workers secondarily exposed are construction tradespersons -- for example, plumbers, electricians, and ceiling tile installers -- whose activities can be complementary to, or immediately succeed, asbestos work. Since OSHA's revised asbestos standard will reduce ambient asbestos levels at these sites, any exposure among these workers would also be reduced.

In custodial work in industrial buildings and in commercial and residential buildings, where 13.5 avoided cancers are projected, estimated baseline average exposures (0.046 f/cc) lie below the revised PEL and are derived from data in the asbestos exposure literature [Wickman, et al. 1992]. OSHA's estimate of current exposures to custodians and other building service workers recognizes that these workers may not be receiving the protection afforded other "construction" workers who encounter asbestos on a more frequent basis. Service workers may, in fact, at times be exposed to asbestos at levels exceeding the current PEL and excursion limit. OSHA believes that employees performing custodial duties such as cleaning, sweeping, dusting, vacuuming and floor maintenance presently receive minimal protection from asbestos exposure. This revised asbestos standard explicitly addresses risks to employees performing custodial tasks; consequently, in this final analysis OSHA examined the occupational risks and estimated the expected benefits to service workers in industrial, commercial and residential buildings.

"Long-term exposures to building occupants." Data from the asbestos exposure literature reveal that ambient outdoor exposures to asbestos are quite low, averaging roughly 0.00007 f/cc. Regarding indoor exposures, the Health Effects Institute -- Asbestos Research reports that for 1,377 air samples from 198 different buildings with asbestos-containing materials (ACM), mean exposures were on the order of 0.00027 f/cc, with 90th and 95th percentiles of 0.0007 f/cc and 0.0014 f/cc [HEI-AR, 1991].

The HEI-AR report indicates that improper handling of asbestos fibers can contribute significantly to higher exposure levels to building occupants, even after completion of all asbestos removal jobs at a building. Of 18 building projects where interior perimeter samples were taken, asbestos levels increased in 12 buildings after abatement. The higher exposures were attributed to leakages in glove bags and improper work practices. While the effect of these removal efforts on exposures varied widely, some exposures increased by a factor of 750 [HEI-AR, 1991, p. 5-30]. In at least one case, a building with previously non-detectable asbestos levels later was found to have detectable levels of airborne asbestos.

OSHA believes that the controls mandated by the standard -- such as negative pressure enclosures, wet methods, critical barriers, and HEPA vacuums, to name a few of the more protective controls -- not only should help lower exposures to employees working in and around them, but should also be nearly 100 percent effective in preventing migration of stray asbestos. Controls required by the revised standard are therefore expected to enhance protection of service workers and building occupants. While any building owner can choose to have ACM removed from a property, owners of buildings with higher concentrations of asbestos, and therefore greater exposure potential for building employees and occupants, are relatively more likely to opt for removal.

Low-level asbestos concentrations can become elevated and remain elevated for long periods of time, as residual asbestos is disturbed. Recent long-term data suggest that after a year's time, exposure levels cease to fall and may actually rise [Wall Street Journal, 1993]. If new asbestos fibers are continually introduced to the general building environment, background asbestos levels could remain elevated and potentially increase.

Based on the Environmental Protection Agency's 1984 survey of buildings [EPA, 1984], OSHA estimates that approximately 156 million maintenance and custodial projects occur annually in 648,000 commercial and residential buildings in which friable asbestos may be disturbed [OSHA, 1994]. Buildings containing friable asbestos constitute less than 20 percent of all buildings with asbestos-containing materials and are believed to have the highest exposure levels. Applying data from the Energy department and Census bureau, OSHA estimates that an average of 18 employees per building are at risk annually from stray asbestos exposures in commercial buildings with friable asbestos, yielding an estimated total population of 11.7 million employees (648,000 buildings x 18 employees per building) [Dept. of Energy, 1986; Dept. of Commerce, 1993]. In this analysis OSHA assumed, based on data from HEI-AR on the distribution of asbestos exposures in public buildings, that higher-risk buildings have a mean current baseline exposure of 0.0014 f/cc (95th percentile of HEI-AR data), in the absence of OSHA-mandated controls. OSHA further assumed that the use of OSHA controls would lower mean background asbestos exposures to levels (0.00035 f/cc) projected by OSHA for custodial workers. Applying these exposure levels to the asbestos risk model, OSHA estimated that 14.2 cancers would be prevented annually among building occupants. It should be noted that this estimate is based solely on exposures to employees working in commercial and residential buildings and does not include exposures to residents and other non-employees, such as students, who may also be exposed while in these buildings.

Other Health Benefits

"Asbestosis." Applying pre- and post-regulation exposures to the asbestosis risk model detailed in the 1986 RIA, OSHA estimates that compliance with the revised final rule will prevent approximately 14 cases of disabling asbestosis annually, among workers directly exposed to asbestos in general industry, shipyards, and construction. In addition, non-quantified benefits of avoided cases of asbestosis are anticipated for building occupants and others secondarily exposed. As these cases represent disabilities and not deaths, they are not included in the total estimated benefits. Asbestosis cases often lead to tremendous societal costs in terms of health care, worker productivity, and in the quality of life to the affected individual. Their prevention, therefore, would have a positive economic effect.

"Reduction of solvent exposures." Presently, approximately 25 percent of auto service establishments rely upon solvent sprays to control asbestos exposure. The most commonly used solvent has been 1-1-1 trichloroethane, a neurotoxin. OSHA attempted to establish a short-term exposure limit for this substance in the 1989 Air Contaminants rulemaking [54 FR 2333], but that rulemaking was stayed by the courts for technical reasons. The revision to the final asbestos rule, by discouraging the use of solvent spray as a control method, will prevent peak trichloroethane exposures to over 150,000 workers. Moreover, 1-1-1 trichloroethane, a chlorofluorocarbon, has been linked with depletion of the ozone layer, thereby possibly contributing to development of skin cancers. Partly as a result of this, some automotive service establishments have switched to a spray based on perchloroethylene, a flammable carcinogen. OSHA believes that as these establishments select control technologies that are feasible alternatives to solvent spray, there will be reduced risks of cancer and fires (from rags contaminated with solvent) as a consequence of the revision to the standard.

Economic Benefits

"Building reoccupation." Significant economic benefits may be derived from lowering asbestos exposures to long-term building occupants. The more rapidly that building owners, whether private or public, can put their asbestos-contaminated building areas back into use, the sooner they can derive explicit or implicit "rental" value. For example, the HEI-AR report discusses an asbestos abatement job at a college building with pre-abatement exposure levels of 0.0002 f/cc [HEI-AR, 1991, p. 5-37]. Shortly after abatement, exposure levels of 0.065 f/cc were measured. After 26 weeks, exposure levels were measured at 0.0008 f/cc. Reoccupation occurred after 35 weeks, when exposures had decreased to 0.0004 f/cc. In this example, the building was not deemed usable for eight months, until exposures began to approach pre-abatement levels.

EPA's asbestos National Emission Standards for Hazardous Air Pollutants (NESHAP) require that asbestos be lowered to specified levels (although not as low as pre-abatement levels) before certain buildings can be reoccupied. These requirements have been built into many asbestos abatement contracts for liability reasons. OSHA calculated, as a hypothetical example, that if reoccupation of portions of 5,000 office buildings, with an annual rental value of $100,000 each, were delayed for 6 months in order for asbestos levels to settle, there would be a deadweight economic loss of $250 million to building owners and society.

"Asbestos liability savings." As discussed in the section on REGULATORY AND NON-REGULATORY ALTERNATIVES, asbestos liability has become a major area of tort litigation. Roughly $8 billion has been spent on asbestos litigation in the last decade [Wall Street Journal, 1992; OSHA, 1986]. The dollar amount of awards has exploded in the last decade. Industry observers forecast that up to $80 billion will be spent on asbestos abatement over the next 20 years, largely as a result of a fear of lawsuits [Wall Street Journal, 1992].

Building owners commission asbestos removal in an attempt to eliminate, or at least reduce, the probability of future lawsuits. Although the likelihood of future lawsuits is uncertain, building owners presumably calculate that the "expected" cost of such lawsuits would run over $4 billion a year, on average (using the 20-year forecast given above). If an individual building owner spends $50,000 to remove the asbestos from a building to avert potential future lawsuits, the owner may be implicitly calculating that such an expenditure will effectively eliminate a 5 percent chance that the owner will have to pay out over $1 million in a lawsuit.

Unfortunately, the evidence suggests that such attempts to reduce the probability of lawsuits, in the absence of proper protections, may be in vain. As discussed elsewhere in this BENEFITS section, recent evidence suggests that such removal attempts, in the absence of proper protections, may actually increase building occupants' exposure to asbestos. Ultimately, exposure to asbestos is the impetus for lawsuits. While it might be arguable, from an exposure standpoint, that the building owner's most economical choice would be to encapsulate existing asbestos, the path of minimizing liability is driving many building owners to actually remove the asbestos. It appears that successful avoidance of liability is guaranteed only by taking all feasible measures to minimize exposures to occupants during removal. Thus, spending an additional $5,000 for worker health to complete a $50,000 removal operation could ultimately prevent a $1 million lawsuit.

This analysis suggests, then, that the asbestos standard's requirements for engineering controls and work practices, including the use of negative pressure enclosures and other isolation efforts, if successful in averting lawsuits, would have a market value of upwards of $4 billion a year (the minimum value of averting lawsuits). Note that there need not actually be over $4 billion a year in lawsuits; the market behavior of owners willing to pay for asbestos abatement simply reflects the market value to those owners of minimizing the likelihood of lawsuits, in effect acting as a type of insurance policy. Moreover, as discussed above, it is not necessary that such efforts be 100 percent successful in preventing lawsuits -- the estimated effectiveness in reducing the probability or value of potential lawsuits possesses considerable value. Additionally, it is not necessary that such controls dramatically reduce exposures to building occupants, although OSHA's analysis indicates that they will, as long as it is established that all feasible measures were taken to minimize asbestos exposures to building occupants so that owner negligence cannot be the grounds of a lawsuit. If instituting the asbestos controls mandated by the OSHA standard were only marginally effective in reducing the probability of lawsuits, say by 10 percent, the use of these preventative measures would still possess a value of over $400 million.

Finally, asbestos removal efforts reflect concern over liability claims from building occupants, and perhaps custodians and maintenance personnel. It does not include the value of prevented claims from workers who must remove the asbestos. The revised asbestos standard eliminates significant risk to the extent feasible, as defined by law, and thereby minimizes secondary liability created by attempts to minimize primary liability.

E. Technological Feasibility and Compliance Costs

This section examines the technological feasibility and estimated costs of compliance for the final revised asbestos standard.

Technological Feasibility

"General industry." OSHA's 1986 Regulatory Impact Analysis [OSHA, 1986] described in detail the controls that would be necessary in order to achieve a PEL of 0.2 f/cc in each of the affected sectors in general industry. OSHA determined that compliance with the 0.2 f/cc PEL was feasible through the use of wet methods, engineering controls, and housekeeping practices. In addition, for the following operations compliance with the PEL of 0.2 f/cc was generally not achievable without the use of respirators: the dry mechanical process in A/C pipe manufacturing and the dry mechanical, wet mechanical, and nuclear ripout processes in ship repair. Compliance with the 1.0 f/cc excursion limit promulgated in the 1988 rulemaking was also expected to lead to occasional respirator use in high-exposure activities throughout primary and secondary manufacturing [OSHA, 1988].

For the revised PEL of 0.1 f/cc, some manufacturing operations will need to supplement engineering controls and work practices with respiratory protection. In all, 2,345 workers (or less than 1 percent of the 682,685 workers exposed in all affected industry sectors) in general industry are expected to need respirators at least part of the workday in order to maintain exposures below the revised PEL. Since all affected employers in general industry will be able to comply with the proposed PEL through the use of engineering controls or, where necessary, respirators, OSHA concludes that the proposed PEL is technologically feasible.

In addition to respirators, ancillary controls will also be needed in affected industry/process groups as a result of the lowering of the PEL. These controls include:

* Regulated areas;

* Disposable protective clothing and gloves;

* Changerooms and lockers;

* Shower rooms;

* Lunch areas; and

* Annual update of the written compliance program.

All ancillary controls required by the revised general industry standard are currently in extensive use throughout industry and are therefore technologically feasible.

Paragraph (k)(7) Care of asbestos-containing flooring material, prohibits for the first time, sanding and high-speed (greater than 300 RPM) stripping of floor material. This new housekeeping paragraph also requires that burnishing and dry buffing of asbestos-containing flooring be performed only when a finish on the flooring is sufficient to prevent contact with ACM. Evidence from the record indicates that many building maintenance personnel are currently meeting these requirements (Tr. 2/7/91 at 4256-4270, Ex. 7-91). Therefore, new Paragraph (k)(7) is technologically feasible.

Lastly, the final revision to the current standard requires certain engineering controls and work practices for brake and clutch repair and services. These requirements include the mandatory use of a negative pressure enclosure/HEPA vacuum method, a low pressure/wet cleaning method, or an alternate method capable of reducing exposure levels to or below levels achieved by the enclosure/HEPA vacuum method. Brake shops performing fewer than six brake or clutch repair jobs per week are permitted to use Method [D] Wet Methods in revised Appendix F of 1910.1001. According to the National Automobile Dealers Association, both the enclosure/HEPA vacuum method and the low pressure/wet cleaning method are currently in use throughout the automotive brake and clutch repair industry (Ex. 7-104); therefore, the revised control requirements for brake and clutch repair are judged by OSHA to be technological feasible.

"Construction." The evaluation of technological feasibility in construction focused on the various combinations of engineering controls, work practices, and respiratory protection necessary to reduce current exposures to achieve compliance with the final PEL of 0.1 f/cc. In addition, OSHA examined a number of engineering controls, work practices, and ancillary requirements which will directly and indirectly contribute to reducing employee exposures. Exposures to asbestos in the construction industry were classified into six activity categories:

* "New construction" -- including the installation of asbestos/cement (A/C) pipe and sheet. New construction falls under Class III asbestos work as defined in the revised asbestos standard.

* "Asbestos abatement" -- including both asbestos removal and encapsulation with a polymeric coating, or enclosure. Asbestos abatement falls under asbestos work Classes I and III as defined in the revised standard.

* "Demolition" -- involving asbestos removal prior to the demolition of all or part of a building or industrial facility that contains asbestos materials. Demolition falls under asbestos work Class I as defined in the revised standard.

* "General building renovation and remodeling" -- including drywall demolition involving the removal of pipe and boiler insulation, fireproofing, drywall tape and spackling, acoustical plasters, transite panels, built-up roofing and flooring products. Renovation and remodeling generally involve contact with generic building materials and would therefore fall under asbestos work Class II as defined in the revised standard.

* "Routine facility maintenance in commercial/residential buildings and in general industry" -- including maintenance and repair activities involving disturbance of asbestos materials and products (for example, repair of leaking steam pipes, ceiling tiles, roofing, drywall, or flooring; or adjustment of HVAC equipment above suspended ceilings). Routine maintenance falls under Class III asbestos work as defined in the revised standard when asbestos-containing materials (ACM) are disturbed during the maintenance activity; and under Class IV asbestos work as defined in the revised standard when maintenance involves minor, incidental contact with ACM.

* "Custodial Work" -- including sweeping, dusting and other housekeeping duties that occasionally expose building maintenance and custodial personnel to asbestos. Custodial work falls under Class IV asbestos work as defined in the revised standard.

To support the regulatory impact analysis for the 1986 asbestos standard, CONSAD derived baseline exposure levels for each construction activity from a database that included personal and area air samples, OSHA inspection reports, expert testimony, and various published reports [CONSAD, 1990]. The technological feasibility assessments for this final revised standard were influenced by expected exposure reduction following the promulgation of the 1986 asbestos standard, and by a review of the literature, including submittals to the OSHA docket (H-033e).

OSHA determined in 1986 that, for a variety of construction activities, it was feasible to reach the current PEL of 0.2 f/cc through the use of available engineering controls and work practices (i.e., without the need for respiratory protection). These construction activities included:

* Asbestos/cement (A/C) pipe installation;

* Asbestos/cement (A/C) sheet installation;

* Floor products installation;

* Plumbing repairs in commercial/residential buildings;

* Floor repairs in commercial/residential buildings;

* Gasket removal and installation in general industry; and

* Pipe insulation repairs in general industry.

For the remaining activities, respiratory protection was necessary in order to reach the current PEL of 0.2 f/cc. OSHA assumed that employers would choose the most cost-effective approach and supply their workers with half-mask supplied-air respirators (or full-facepiece supplied-air respirators for asbestos removal projects) in order to eliminate the need for exposure monitoring [OSHA, 1986]. Thus, in the 1986 RIA, OSHA assumed that workers in many higher-risk construction activities would be provided supplied-air respirators.

OSHA now believes that the prior analytical assumption of widespread use of supplied-air respirators may not be consistent with field experience. OSHA believes that supplied-air respirators are used in many construction activities -- particularly removal and demolition, where exposures tend to be highest. For other construction activities where peak exposures are generally lower and episodic, many abatement and maintenance personnel appear to be complying with the current standard using a combination of engineering controls, work practices and lighter respirators.

Construction employers also appear to meet the requirements for daily monitoring (1926.58(f)(3) in the current standard) by compiling historical exposure data documenting compliance with the current OSHA PEL during representative projects. OSHA anticipates that some construction employers will meet the requirements of revised Paragraph (f) Exposure assessments and monitoring, through the use of selective initial monitoring to establish an historical exposure data record, which can form the basis for achieving all necessary requirements of the standard. Where exposures may exceed levels documented by objective data, additional respiratory protection may be necessary, and is judged by OSHA to be technologically feasible based on field experience and information in the rulemaking record [Corn, 1992; HEI-AR, 1992].

As in the standard for general industry, OSHA is proposing the prohibition of high-speed sanding and the use of highly abrasive pads during asbestos floor tile work. In CONSAD's 1985 study [CONSAD 1985] and in OSHA's 1986 RIA [OSHA, 1986], exposures during floor tile installation, removal, and sanding were reported to be generally below 0.2 f/cc when the recommendations of the Resilient Floor Covering Institute were followed. These recommended practices included wet sweeping and handling, and the prohibition of power sanding and blowing asbestos dust. OSHA estimated current exposures in floor repair at 0.024 f/cc under the assumption that the Institute's recommended practices have been adopted by a majority of establishments. Therefore, the prohibition of high-speed sanding in the current proposal is not expected to significantly affect floor repair.

With the final PEL of 0.1 f/cc, additional respiratory protection may be necessary. Specifically, some projects involving A/C pipe installation, A/C sheet installation, floor removal, floor repair, large-scale gasket removal, pipe repair, and custodial work in industrial, commercial and residential buildings would require the use of half-mask respirators to meet the revised PEL. In addition, drywall demolition projects may need to upgrade their respiratory protection to full-facepiece negative-pressure respirators to meet the lower permissible exposure limit.

Assessing current respirator usage and predicted demand under the revised standard, OSHA concludes that nearly all construction activities will require respiratory protection during at least part of the project-day in order to comply with the 0.1 f/cc PEL. Based on the lower-bound exposure estimates provided in the literature and reported in CONSAD [CONSAD, 1990, 1985], it appears that a variety of routine maintenance activities and some abatement jobs may be able to achieve the proposed PEL of 0.1 f/cc without respirators. From its analysis of current exposures, OSHA anticipates that only in small-scale gasket removal and installation will respiratory protection not be necessary for most project-days.

The other incremental controls necessary to comply with OSHA's final asbestos standard, include (depending upon the construction activity):

 

  • * HEPA vacuums or HEPA vacuum/ventilation systems;
    * Wet methods;
    * Glove bags;
    * Regulated areas (air-tight or demarcated with caution signs);
    * Critical barriers;
    * Protective disposable clothing;
    * Impermeable drop cloths;
    * Decontamination area (adjacent to regulated area or remote showers
    and changerooms);
    * Lunch areas;
    * Competent person supervision;
    * Training;
    * Medical exams;
    * Recordkeeping (exposure assessment, medical exams and training);
    * Notification of building owners and employees by contractors;
    * Notification of contractors and building occupants by building
    owners;



  •  

 

Based on information in the record and in OSHA's inspection files, OSHA observes that many construction employers currently apply these controls in varied combinations and at varied levels of utilization. OSHA estimated that for construction employers, rates of current compliance range from roughly 20 percent to 80 percent, depending on the control requirement and construction activity. Therefore, OSHA believes all controls are technologically feasible for the appropriate construction activities. In conclusion, therefore, OSHA projects that the final revisions to the asbestos construction standard will be technologically feasible because all of the provisions, including the lowered PEL, can be met using existing engineering controls, respiratory protection and work practices.

"Shipyards." Historically, exposure to asbestos in shipyards took place during shipbuilding and ship repair. At present, the majority of asbestos activity aboard maritime vessels involves repair and maintenance of machinery and plumbing with asbestos insulation. In this final rulemaking, the revised asbestos standard for shipyards, Sec. 1915.1001, applies most of the requirements given in the revised asbestos construction standard.

For the two main shipyard activities affected by the revised asbestos standard -- wet removal/repair and dry removal/repair -- comment in the record [Ex. 7-77, Ex. 7-85] suggests that employers are able to achieve the revised PEL of 0.1 f/cc through the use of engineering controls and, where necessary, respiratory protection. The OSHA Shipyard Employment Standards Advisory Committee [Ex. 7-77] commented that on many shipyard projects, exposure levels have been reduced to levels considerably below the revised PEL. Moreover, to a large extent employers appear to be currently applying the ancillary controls and work practices required in the revised construction standard (and applied to the revised shipyard standard) [Ex. 9-23]. Therefore, on the basis of evidence in the record, OSHA believes the revised shipyard standard is technologically feasible.

Compliance Costs

OSHA estimated the costs of complying with the final revisions to the asbestos standard for general industry, construction and shipyards. OSHA's cost assumptions and methodologies are based upon an OSHA/CONSAD technical analysis of the final rule [OSHA, 1994]; OSHA's PRIA [OSHA, 1990]; CONSAD's final report supporting the PRIA [1990]; the rulemaking record; and previous regulatory analyses performed by OSHA [OSHA, 1986], CONSAD [CONSAD, 1985] and Research Triangle Institute [RTI, 1985].

Cost data for control mechanisms were obtained from published price lists of equipment suppliers and from other information collected by OSHA and CONSAD. Wage data were taken from the U.S. Department of Labor's Bureau of Labor Statistics' Employment and Earnings (BLS, 1993a) and Employment Cost Indexes and Levels (BLS, 1993b). Unit costs are expressed, as appropriate, on a per-establishment, -crew, -project, -worker, project-day, and worker-day basis, using industry profile data presented in the OSHA/CONSAD technical analysis [OSHA, 1994] and in CONSAD's prior analyses [CONSAD, 1990, 1985].

To derive estimates of the annual incremental compliance costs for the revised asbestos standard, the estimated unit cost factors for the controls were multiplied by the estimated number of required control resources. In order to develop net annual compliance cost estimates, these gross annual cost estimates were then adjusted using estimates of current application of controls. Costs were estimated on an annual basis, with total annual costs calculated as the sum of annualized initial costs and annual recurring costs. Initial costs were annualized over the service life of the equipment or administrative activity, at a discount rate of 10 percent.

The section below presents the estimated costs to general industry, followed by the costs to construction and to shipyards.

"General industry." In developing the annual compliance cost estimates for general industry, unit cost estimates were first developed for each of the control practices and ancillary measures required by the revised standard for each of the industry/process groups affected by the proposed standard. The annual compliance costs for each affected industry/process group were then computed by combining the unit cost data with the number of units of each type of control practice needed per year to achieve compliance with OSHA's proposed standard. Compliance costs were also adjusted to reflect current compliance with the required control practices.

"Manufacturing." The industry/process groups in manufacturing with exposures above the revised PEL of 0.1 f/cc will require the implementation of a set of uniform control practices, including written compliance programs, regulated areas, respirators (including the respirator unit, accessories, fit testing and cleaning), disposable protective clothing and gloves, change rooms and lockers, shower rooms, and lunch rooms. Other controls, while necessary for compliance with the revised standard, are also required by the current asbestos standard and, thus, will not create an incremental burden. Controls assumed by OSHA to be currently in place include periodic monitoring; prescribed methods of compliance; employee information and training; medical surveillance; and recordkeeping.

The revised asbestos standard for general industry imposes new communication requirements for building and facility owners. In particular, under Paragraph (j)(2)(ii), owners are required to maintain records of information concerning the presence, location and quantity of asbestos-containing material (ACM) and presumed asbestos-containing material (PACM). Under Paragraph (j)(2)(iii), owners of buildings and facilities are required to inform employers of employees who perform housekeeping activities in the presence of ACM or PACM of the presence and location of the ACM or PACM in the area. In this regulatory analysis OSHA treats housekeeping and custodial activities in general industry as construction activities. OSHA's estimated compliance costs for information requirements pertaining to housekeeping/custodial activities are discussed below in the section on compliance costs for the revised construction standard.

Brake and clutch repair. As in the existing OSHA asbestos standard for general industry, automotive repair work is regulated in revised Sec. 1910.1001. In Paragraph (f)(3) employers performing six or more brake or clutch jobs per week are required to use a negative pressure enclosure/HEPA vacuum method, a low pressure/wet cleaning method, or an alternate method proven to achieve results equivalent to those for the enclosure/HEPA vacuum method. OSHA assessed the extent to which control practices are being applied during brake and clutch repair in the automotive services industry and identified the additional resources needed to reach full compliance with the revised standard.

Based on OSHA's and CONSAD's assessment of current industry practice, OSHA believes that only a small fraction of auto repair shops perform fewer than six brake or clutch inspections per week [OSHA, 1994]. Thus, OSHA anticipates that few shops will qualify for the exemption from engineering controls mandated in revised Appendix F. OSHA and CONSAD [OSHA, 1994] estimate that 65 percent of brake shops currently use wet methods and solvent spray systems during brake and clutch work. Under the revised standard, these shops would have to switch to one of the fiber control methods permitted in Appendix F.

For this cost analysis, OSHA assumed most of the shops currently not in compliance with the revised rule, will adopt the low pressure/ wet cleaning method as the least expensive option permitted in the revised standard. OSHA estimates that incremental expenditures for equipment, supplies and labor time will total $11.2 million per year.

Comment in the record [Ex. L162-61] points to the potential for substantial cost offsets from use of the low pressure/wet cleaning method. These cost offsets include the reduced need for solvent; reductions in costs associated with housekeeping and with laundering and disposal of contaminated rags and other articles; and improved operating efficiencies. Because of potential cost savings, use of the low pressure/wet cleaning method has grown in recent years. Moreover, concern over the effect of 1-1-1 trichloroethane on the ozone layer has led to a phase-out of the solvent, forcing brake shops to discontinue use of the solvent spray method. Of concern to occupational health specialists is the regular use of solvents among a workforce with minimal protection from exposures. In sum, OSHA believes that cost offsets and environmental and health concerns combine to mitigate the direct costs facing brake shops who must switch to alternative asbestos control systems.

"Current work practices." In addition to work practices in automotive services that meet the revised standard, certain work practices that were required by OSHA's previous standard with a PEL of 2.0 f/cc, and are required by the current standard, as well as by the proposed revisions to the current standard (e.g. wet handling and the collection, disposal, and labeling of wastes in sealed, impermeable bags), are also not identified as additional costs. OSHA believes that wet methods (to the extent that they are feasible), and the use of HEPA vacuums for housekeeping in primary and secondary manufacturing, are already widely in use.

"Total costs for general industry." To derive estimates of the annual incremental compliance costs for the industry/process groups affected by the revised general industry standard, the estimated unit cost factors were first multiplied by estimates of the resources necessary to achieve compliance for that industry/process group. These gross annual cost estimates were then adjusted to account for current compliance rates which were first projected in the 1986 RIA [OSHA, 1986] and were modified as a result of compliance with the excursion limit rule in 1988 [OSHA, 1988] and evidence from the rulemaking record.

For each of the manufacturing processes in the affected industries, CONSAD estimated the number of plants with exposures above the revised PEL of 0.1 f/cc (the number of plants needing controls), the number of processes to be controlled, the number of work stations to be controlled, the number of workers directly exposed, worker-days of exposure per year, and the direct worker-hours of exposure per year. These estimates are based on: the number of establishments in each industry sector, determined by CONSAD from information presented in EPA's ban and phase-out rule [ICF, 1988], and from contacts with industry experts; the percentage of processes within plants with exposures above the proposed PEL of 0.1 f/cc and requiring controls; and finally, characteristics concerning the number of processes per plant, work stations per process, workers per work station, and the frequency and duration of each process in these affected industries. The resource estimates used to develop annual compliance costs are developed in detail in [CONSAD, 1990, Table 3.11].

Based on OSHA and CONSAD's analysis [OSHA, 1994; CONSAD, 1990], OSHA estimates that annual costs of compliance in general industry will total $14.8 million. Table 7 presents compliance costs by control practice, for each industry process, for the industry sector as a whole, and for all of general industry. Examining compliance costs by sector, it can be seen that the largest compliance expenditures will be in auto repair ($11.2 million), followed by friction materials ($2.2 million) and coatings and sealants ($1.2 million).

Table 7. -- Estimated Annual Costs of Compliance For
General Industry Sectors

(For Table 7, see printed copy)

Comparing costs per provision along the bottom row of the table, incremental costs for engineering controls in auto repair represent the leading expenditure. Other controls bearing significant costs are half- mask respirators ($1.4 million), disposable protective clothing and gloves ($1.1 million), change rooms and lockers ($563 thousand), and shower rooms ($418 thousand).

For secondary manufacture of gaskets and packings and secondary auto remanufacturing, where exposures currently are below the revised PEL, OSHA anticipates little or no incremental costs. Therefore, impacts on establishments in these industry groups will be insignificant.

"Construction." Within the construction industry, 24 unique activities will come under the scope of the proposed revision. These construction activities are found in new construction, asbestos abatement and building demolition, general building renovation and remodeling, and routine facility maintenance and custodial work in public, commercial, and residential buildings and in general industry. Although the construction activities under consideration in this study will require the implementation of different control practices and/or combinations of these practices, the basic characteristics of available control practices are relatively uniform, and the options for combining control practices in the construction industry and during routine maintenance and repair activities in general industry are limited in number.

The control mechanisms considered in this analysis include:

 

  • * Shrouded tools with HEPA vacuums;
    * HEPA vacuum/ventilation systems;
    * HEPA vacuums;
    * Glove bags;
    * Critical barriers (including the materials and labor for setting up
    and taking down;
    * Regulated areas;
    * Respirators (including the respirator unit, accessories, fit testing,
    cleaning, and training);
    * Disposable protective clothing and gloves;
    * Impermeable drop cloths;
    * Wet methods (including the sprayer, wetting agent, and labor);
    * Decontamination areas (or clean changerooms);
    * Lunch areas;
    * Training;
    * Use of competent person supervision;
    * Exposure assessments and monitoring;
    * Medical exams;
    * Recordkeeping;
    * Labeling of installed asbestos products;
    * Notification of building owners and employees by contractors; and
    * Notification of contractors and building occupants by building
    owners.


  •  

 

Certain work practices that have been required since OSHA's earlier asbestos standards (e.g., wet handling and the collection and disposal of waste in sealed, impermeable bags) are not included as cost elements.

For each major provision of the revised construction standard, below, OSHA presents cost estimates by type of engineering or administrative control, work practice or personal protective equipment, where appropriate.

(c) "Permissible exposure limits." The revised asbestos construction standard lowers the permissible exposure limit from 0.2 fiber per cubic centimeter to 0.1 fiber per cubic centimeter of air as an eight-hour time-weighted average. The revised standard retains the current excursion limit of 1.0 fiber per cubic centimeter of air as averaged over a sampling period of thirty minutes.

After reviewing both (1) the literature on risk to asbestos in the construction industry and (2) the earlier OSHA rulemaking record (Docket H-033c), CONSAD [CONSAD, 1990, Table 2.8] reported representative exposure levels by construction activity that formed the basis of OSHA's risk estimates in the PRIA. CONSAD presented the range of exposure levels in the absence of respiratory protection for each construction activity. From the raw exposure data, OSHA [1986, 1990] developed arithmetic mean estimates, against which the proposed PELs were compared. OSHA then assigned engineering and respiratory controls as required and implied by the earlier rules.

For this final regulatory impact analysis, OSHA adjusted CONSAD's baseline (pre-1986) exposure levels to reflect likely controls applied since OSHA promulgated final asbestos rules in 1986 and 1988. In adjusting exposures from baseline levels, OSHA attempted to represent realistic reductions in fiber levels under a regulatory regime consisting of a 0.2 f/cc eight-hour PEL, a 0.1 f/cc eight-hour action level, a 1.0 f/cc thirty-minute excursion level, and ancillary controls and procedures. OSHA's adjusted baseline exposures were presented in Section D.

OSHA's revised PEL is expected to lead to wider use of respirators in construction. In particular, OSHA anticipates increased usage of half-mask and full-face cartridge respirators as a result of the revised PEL. For some activities where average exposures are projected to be below the PEL due to the use of engineering controls and work practices, respirators may be necessary where peak exposures occur. OSHA conservatively applied half-mask cartridge respirators, with a protection factor of 10, where peak exposures can exceed ten times the revised PEL; OSHA applied full-facepiece cartridge respirators for activities where peak exposures can exceed 50 times the revised PEL. In all, annual respirator costs will total $24.9 million. Included in this total cost are expenditures for the respirator unit, accessories, filters, training (costs assigned under Paragraph (k) Communication of hazards), cleaning and fit testing.

(d) "Multi-employer worksites." Revised Paragraph (d) expands upon the current requirement that an employer performing asbestos work in a regulated area inform other employers on the site of the nature of the employer's work with asbestos and the existence of, and rules pertaining to, regulated areas. In addition, Paragraph (d) requires * Abatement of asbestos hazards by the contractor controlling the source of the contamination -- (d)(2) * Protection of employees adjacent to asbestos worksite -- (d)(3) * Daily assessment by adjacent employers of integrity of enclosures or effectiveness of other control methods relied on by the primary asbestos contractor -- (d)(4) * Supervisory authority by general contractors over the work of the asbestos contractor on the asbestos worksite -- (d)(5).

OSHA anticipates significant compliance costs for three of the four additional requirements in the revised paragraph on multi-employer worksites. For provisions (d)(2) and (d)(3), OSHA believes that compliance with the requirements for PELs [Paragraph (c)] and initial exposure assessment [Paragraph (j)] will ensure compliance with these areas. Regarding daily assessment of work areas, required by (d)(4), OSHA considers these duties to fall under the supervision of competent persons. Compliance costs for competent persons are discussed below under Paragraph (o).

For Paragraph (d)(5), OSHA assumes that after promulgation of the revised standard, asbestos contractors will achieve full compliance and, therefore, that general contractors will rarely need to exercise authority over employee protection.

(e) "Regulated areas." Paragraph (e) specifies the controls required for construction activities designated as regulated areas. OSHA anticipates incremental costs for all construction work defined in the revised standard as Class I, II or III. Incremental costs for regulated areas will stem from the need for caution and warning signs and caution tape at the perimeter of work areas, as required by (e)(2) Demarcation and (k)(6) Signs. OSHA anticipates total costs of $15.8 million for caution and warning signs.

(f) "Exposure assessments and monitoring." Revised Paragraph (f) alters current requirements for initial exposure monitoring, periodic monitoring, termination of monitoring, additional monitoring, employee notification of sampling results, and observation of monitoring. OSHA anticipates that following promulgation of this revised standard, many employers will initially monitor higher-risk sites -- under conditions of full application of controls -- in order to establish compliance with the revised PEL of 0.1 f/cc. Results from initial monitoring can be used as historical, objective data for compliance purposes, consistent with revised (f)(1)(iii) Negative initial exposure assessment.

To estimate monitoring costs in construction, OSHA assumed -- for activities where objective data has not been established -- that employers conducting Class I, II or III work, will purchase monitoring equipment, train a supervisor to conduct monitoring, and have three representative exposure samples analyzed by a laboratory. OSHA assumed that employers conducting Class IV activities will hire an outside industrial hygiene technician to monitor workers and collect three exposure samples. Basing cost analysis on these assumptions, OSHA projects total incremental compliance costs of $40.1 million for exposure monitoring.

(g) "Methods of Compliance." In revised Paragraph (g) Methods of compliance, OSHA has significantly expanded the structure and content of the regulatory text in the current standard. Revised Paragraph (g) prescribes specific engineering controls and work practices for each of the four asbestos construction classes defined in the standard. To satisfy the requirements for ancillary controls, employers are expected to purchase or otherwise adopt the following types of controls and practices: HEPA vacuum/ventilation systems; HEPA vacuums; wet methods; airtight (negative-pressure) regulated areas; drop cloths; mini enclosures; critical barriers; and glove bag systems (with HEPA vacuums). Included in the cost of each control are expenditures for basic equipment, accessories, construction supplies (for barriers and enclosures), smoke testers (for negative-pressure enclosures), and incremental labor resources needed to implement the control, to smoke test (where necessary) and to disassemble the control.

Incremental compliance costs associated with engineering controls and work practices are anticipated for all construction activities affected by the revised standard. The combination of controls vary by activity, depending on current exposure levels, the extent of current compliance assumed by OSHA, and the construction class (as defined in the revised standard) for the work activity. OSHA projects the following annual compliance costs for methods of compliance:

* HEPA vacuum/ventilation systems -- $15.3 million

* HEPA vacuums -- $32.5 million

* Wet methods -- $55.2 million

* Airtight regulated areas -- $2.2 million

* Drop cloths -- $13.8 million

* Mini enclosures -- $41.6 million

* Critical barriers -- $22.2 million

* Glovebag systems -- $4.5 million.

(h) "Respiratory protection." Revised Paragraph (h) mandates the use of respirators under particular circumstances during asbestos construction work. As prescribed in the standard, respirators must be worn (1) during all Class I work; (2) during all Class III work when TSI or surfacing ACM or PACM is being disturbed; (3) during all Class II and III asbestos jobs where wet methods are not used or where insufficient or inadequate data prevents development of a negative exposure assessment; or (4) in emergencies. For this final regulatory impact analysis, OSHA identified an additional need for respirators in new construction, during removal and repair of flooring products, during routine maintenance in general industry, and during custodial work in industrial, commercial and residential buildings. Respirators were assigned to construction activities where baseline exposure ranges suggested workers would occasionally exceed the revised PEL. Incremental compliance costs for respirators were presented above under (c) Permissible exposure limits.

(i) "Protective clothing." Paragraph (i) in this final rulemaking has been revised such that protective clothing will be required for all Class I activities and in Class III activities where thermal system insulation or surfacing ACM/PACM is being disturbed in which a negative exposure assessment has not been produced, in addition to the requirement that clothing be worn when the PEL or excursion limit (EL) is exceeded. OSHA anticipates an additional need for protective clothing in the following construction activities where workers may occasionally exceed the PEL:

* A/C pipe installation

* A/C sheet installation

* Remove flooring products

* Repair flooring

* Custodial work in industrial buildings

* Custodial work in public, commercial and residential buildings.

OSHA assumes that to provide protective clothing to employees as required by the standard, employers will minimize costs by providing to each employee one set of disposable clothing and gloves for each worker-day. For disposal, clothing can be combined with other contaminated waste and sealed in impermeable bags. Summing incremental costs for protective disposable clothing, OSHA estimates total costs of $17.9 million associated with revised Paragraph (i).

(j) "Hygiene facilities and practices for employees." Revised Paragraph (j) provides for decontamination areas, equipment rooms, showers, change rooms, and lunch areas for Class I activities. Class II and Class III activities may conduct decontamination in adjacent areas on impermeable drop cloths, with clothing and equipment cleaned with HEPA vacuums. Decontamination following Class IV activities must be at least as stringent as required for the class of activity within which the Class IV work is being performed.

OSHA anticipates that Class I hygiene requirements will apply for the first time to boiler repair, pipe repair and miscellaneous maintenance in general industry. Annual compliance costs will total $5.5 million for equipment and labor involved with the hygiene facilities in Class I work.

Employers can decontaminate Class II and Class III work using drop cloths and HEPA vacuums, controls required under (g) Methods of compliance. OSHA's estimated costs for drop cloths and HEPA vacuums were presented above in the discussion of revised Paragraph (g).

OSHA assumes that decontamination following Class IV work conducted in regulated areas will be provided by the primary contractor at the job site. Costs for decontamination of Class IV employees, then would be captured by the total decontamination costs for the activity in the regulated area. In addition, OSHA assumed that drop cloths and HEPA vacuums will be needed by custodians following higher-risk activities outside regulated areas. Costs for drop cloths and HEPA vacuums were presented under (g) Methods of compliance, above.

(k) "Communication of hazards." Revised Paragraph (k) supplements the existing hazard-communication requirements in the asbestos standard by introducing provisions for notification of building and facility owners, contractors, employees and building occupants of the presence, location and quantity of asbestos-containing material (ACM) or presumed asbestos-containing material (PACM). The final revisions to (k) also include training requirements that mirror the training required under the EPA ASHARA legislation, for employees working around ACM or PACM. Training required under revised Paragraph (k) appears to strengthen the content of training required under existing (k) by explicitly referencing the EPA Model Accreditation Plan (MAP) and Operations and Maintenance (O&M) worker protection training.(5)

__________

Footnote(5) Revised Paragraph (k) allows employers to substitute -- for Class II activities working with generic building materials -- training suitable to the removal or disturbance of that category of building material.

For this final regulatory impact analysis, OSHA identified incremental compliance costs for employee training and notifications involving building/facility owners, construction employers, construction employees, and building occupants. For the purpose of cost estimation, OSHA categorized employee training into three groups: (1) Classes I and II, (2) Class III, and (3) Class IV.(6) For each of the three categories of training required by the revised standard, OSHA estimated compliance costs as follows:

__________

Footnote(6) Class I training was assumed to require a total of 32 hours, whereas Class II training was assumed to require a total of 24 hours. Total costs for Class I and Class II training are combined in this discussion.

* Class I/II -- $51.8 million

* Class III -- $35.9 million

* Class IV -- $22.6 million.

In that OSHA's training requirements parallel the requirements mandated in EPA's MAP regulation, OSHA attributes to the EPA regulation, training costs in this final revision to the OSHA asbestos construction standard.

To estimate compliance costs of the new notification requirements in revised Paragraph (k), OSHA identified seven unique types of notifications. OSHA assumed that notification among affected parties could involve memos, phone calls, notices or other lower-cost means of communication, ranging in labor time from three to five minutes per project. The types of notifications are given below, along with OSHA's estimated total annual compliance cost.

* Notification by contractor to building owner prior to start of project -- high-risk ACM -- $305 thousand

* Notification by contractor to building owner prior to start of project -- low-risk ACM -- $5.0 million

* Notification by contractors to employees -- $394 thousand

* Notification by contractor to building owner regarding asbestos remaining in building -- $397 thousand

* Notification by building owner to building occupants -- high-risk ACM -- $612 thousand

* Notification by building owner to building occupants -- low-risk ACM -- $22.3 million

* Notification by building owner to all contractors in building --

$6.1 million.

In addition to requirements for notification, Paragraph (k)(2)(iii) requires owners to maintain records of all information indicating the presence, location and quantity of ACM and PACM in the building. OSHA estimated recordkeeping costs of $9.7 million to comply with revised (k).

(l) "Housekeeping." Paragraph (l) is expanded in this final revision to the asbestos construction standard to include a section on care of asbestos-containing flooring material. Included in the new section are a prohibition on sanding of asbestos-containing material; work practices specifying wet methods for floor stripping and adequate floor finish for burnishing and dry buffing; and a requirement that dusting and dry sweeping be performed with HEPA vacuums. OSHA anticipates incremental compliance costs associated with using wet methods and HEPA vacuums during housekeeping duties. Costs for the use of wet methods during custodial work is included in the total costs for wet methods given under (g), above, and are expected to be $55.2 million. Costs for the use of HEPA vacuums during custodial work is included in the total costs for HEPA vacuums given under (g), above, and are expected to be $32.5 million.

(m) "Medical surveillance." Revised Paragraph (m) provides that medical exams be given for all employees whose exposures exceed the PEL or excursion limit for 30 or more days per year, or who are required by the standard to wear negative pressure respirators. For this final RIA, OSHA recognized the extent to which medical exams are currently provided to employees. Therefore, incremental costs were estimated only for employees in those construction activities which previously did not qualify for medical exams but which now appear to meet the qualifications. Activities qualifying for medical exams under the revised standard include the following (along with estimated annual compliance costs):

* A/C pipe installation -- $59 thousand

* A/C sheet installation -- $61 thousand

* Floor removal -- $828 thousand * Floor repair -- $6.5 million

* Large-scale gasket removal in general industry -- $702 thousand

* Pipe repair in general industry -- $1.9 million.

Estimated compliance costs for Paragraph (m) include costs for medical exams and for recordkeeping. In all, $10.1 million in annual costs for medical surveillance are expected for affected construction activities.

(n) "Recordkeeping." Revised Paragraph (n) requires that employers establish and maintain records of objective data (in compliance with (f)), exposure measurements, medical surveillance, and training. Revised Paragraph (n) also provides for availability and transfer of records. Incremental recordkeeping costs for each of these areas were presented above.

(o) "Competent person." Paragraph (o) is a new section of the construction standard and provides for competent person training and supervision for Class I, II, and III activities. Consistent with the distinctions among activity classes in (o), OSHA identified two levels of competent person training: Class I/II and Class III. OSHA estimates that costs for annual Class I/II competent person supervision will be $13.5 million; OSHA estimates annual costs of $6.0 million for Class III competent person supervision. OSHA's estimates of competent person training costs are based on an analysis by EPA's contractor Abt Associates [Abt, 1993], of the costs and benefits of the EPA Model Accreditation Plan regulation.

In addition to competent person supervision, the revised standard requires that the person evaluating compliance methods that are alternatives to those in (g) Methods of compliance, be qualified as a project designer [(g)(6)(ii)]. OSHA estimated the costs for training project designers for Class I activities. At an annual cost of $171 thousand, the training burden implied by this requirement is attributed to the EPA MAP regulation, which provides for training of project designers and other competent persons.

"Total construction costs." Based on OSHA's preliminary regulatory impact analysis [OSHA, 1990], preliminary analysis by CONSAD [CONSAD, 1990], and cost analysis of the revised standard by OSHA and CONSAD [OSHA, 1994], OSHA estimated total costs of compliance with the revised PEL of 0.1 f/cc and the ancillary requirements pertaining to regulated areas, methods of compliance, respiratory protection, hygiene facilities, communication of hazards and competent person training. The estimated compliance costs, by control requirement, are shown in Table 8 for each major construction sector. OSHA's estimate of total cost, $476.4 million, is the average cost for a range of construction workers potentially at risk in each of the activities affected by the standard (see [CONSAD, 1990, Appendix A] and [OSHA, 1994]). This estimate of incremental costs, however, includes the training costs -- for workers, supervisors, project designers and competent persons -- that would otherwise be incurred through compliance with the EPA Model Accreditation Plan regulation. Excluding EPA-related training costs, OSHA estimates that $346.5 million in incremental costs are attributed to the OSHA construction standard. Table 9 presents total annual compliance costs by construction activity, for requirements unique to the revised OSHA construction standard.

Table 8. -- Annual Incremental Compliance Costs For OSHA's
Revised Asbestos Standard For The Construction
Industry, By Construction Category and Control
Requirement

(For Table 8, see printed copy)

Table 9. -- Net Compliance Costs for OSHA's Revised Asbestos
Construction Standard

[By Construction Activity, 1993 Dollars]
Construction activity Annual cost
New Construction:
  • A/C Pipe Installation
$ 578,189
  • A/C Sheet Installation
233,602
Abatement and Demolition:
  • Removal
1,089,688
  • Encapsulation
77,611
  • Demolition
1,095,692
Remodeling and Renovation:
  • Drywall Renovation
4,697,904
  • Remove Roofing Felts § Coatings
436,077
  • Remove Flooring Products
13,183,683
Routine Maintenance in Public, Commercial, and Residential Buildings:
  • Repair ceiling tiles
9,136,115
  • Repair HV AC/lighting
15,612,401
  • Other Work/Drop Ceiling
3,937,675
  • Repair Boiler
16,711,380
  • Repair Plumbing
21,730,412
  • Repair Roofing
8,392,722
  • Repair Drywall
23,276,376
  • Repair Flooring
45,094,590
Routine Maintenance in Industrial Facilities:
  • Remove Gaskets (Small-Scale)
10,490,046
  • Remove Gaskets (Large-Scale)
2,113,420
  • Repair Boilers (Small-Scale)
1,307,159
  • Repair Boilers (Large-Scale)
14,134,324
  • Repair Pipe (Small-Scale)
3,229,996
  • Repair Pipe (Large-Scale)
2,574,361
  • Miscellaneous Maintenance (Small-Scale)
22,462,603
  • Miscellaneous Maintenance (Large-Scale)
4,602,548
  • Telecommunications Maintenance (Small-Scale)
7,972,794
  • Telecommunications Maintenance (Large-Scale)
728,523
Custodial Work in Public, Commercial and Residential Buildings 104,338,415
Custodial Work in Industrial Facilities 7,279,509
    • All Activities
346,517,816
Source: U.S. Department of Labor, OSHA, Office of Regulatory Analysis, based on OSHA, 1994; CONSAD, 1990; and the rulemaking record

"Shipyards." The revised standard for shipyards largely resembles the revised construction standard. OSHA and CONSAD [OSHA, 1994] identified two shipyard activities -- wet removal/repair/installation and dry removal/repair/installation aboard vessels -- where significant contact with asbestos can take place. CONSAD's cost analysis assumes asbestos removal will be performed by abatement specialists currently complying with requirements in the existing asbestos general industry standard (under which asbestos contact during shipbuilding and repairing is presently regulated). Specifically, abatement specialists in shipyards are believed to be currently using the following controls at near-100 percent level:

 

  • * HEPA vacuums
    * Wet methods (where feasible)
    * Regulated areas with caution signs
    * Respirators (full-facepiece cartridge respirators and full-facepiece
    supplied-air respirators)
    * Disposable protective clothing and gloves
    * Decontamination units
    * Lunch areas
    * Training (General Industry standard)
    * Exposure monitoring (daily)
    * Medical Exams
    * Written compliance plan.


  •  

 

For affected shipyards, OSHA's cost analysis assigned engineering controls and work practices required or implied by the revised asbestos standard. OSHA anticipates incremental costs associated with airtight regulated areas; drop cloths; critical barriers; glove bag systems; worker training and competent person training (Class I); initial exposure monitoring and development of objective data; and notification requirements. In all, OSHA projects annual incremental compliance costs of approximately $229 thousand for the shipbuilding and repairing sector. Of these costs, $137 thousand are associated with training required by the EPA Model Accreditation Plan regulation mandated by the ASHARA legislation. Therefore, net OSHA-related annual costs for ship repair under the revised asbestos standard are expected to total approximately $93 thousand (after rounding). Compliance costs for ship repair are presented in Table 10 by control requirements for affected shipboard activities.

Table 10. -- Estimated Incremental Compliance Costs for
Affected Sectors in Shipbuilding and Repairing

[By Activity and Control Requirement, 1993 Dollars]
Wet removal with repair and installation Dry removal with repair and installation Totals
HEPA Vacuum/Ventilation System 7,236 0 7,236
HEPA Vacuums 0 0 0
Wet Methods 0 0 0
Regulated Areas (airtight, caution signs) 4,294 1,073 5,367
Regulated Areas (caution signs) 0 0 0
Drop Cloths 179 45 224
Critical Barriers 385 96 481
Glove Bag Systems (with HEPA Vacuums) 56,132 13,750 69,882
Respirators 0 0 0
Disposable Protective Clothing and Gloves 0 0 0
Decontamination Areas 0 0 0
Lunch Areas 0 0 0
Training -- Class I 105,280 26,270 131,550
Competent Person Training 3,294 0 3,294
Competent Person -- Project Designer 1,680 0 1,680
Exposure Monitoring (initial) 8,983 0 8,983
Exposure Monitoring (semi-annual) 0 0 0
Medical exams -- Initial and Recurring 0 0 0
Notification by Contractor to Facility Owner -- High Risk ACM 89 22 112
Notification by Contractor to Facility Owner -- Low-Risk ACM 0 0 0
Notification by Contractor to Employees 15 4 19
Notification by Contractor to Facility Owner 15 4 19
Notification by Facility Owner to Facility Occupants -- High-Risk ACM 187 47 234
Notification by Facility Owner to Facility Occupants -- Low-Risk ACM 0 0 0
Notification by Facility Owner to Contractors 7 2 9
Recordkeeping by Facility Owner 12 3 15
Totals 187,790 41,316 229,105
Totals Net of EPA -- Related Training 77,535 15,046 92,581
Source: U.S. Dept. of Labor, OSHA, Office or Regulatory Analysis, based on OSHA, 1994; OSHA, 1986; and RTI, 1985

Aggregate incremental compliance costs. As described above, OSHA estimated compliance costs associated with the revised asbestos standard for General Industry, Construction and Shipyards. Total annual costs for each of the three main parts of the asbestos standard are as follows (excluding EPA-related training costs):

 

  • * General Industry -- $14.8 million
    * Construction -- $346.5 million
    * Shipyards -- $93 thousand.

 

Summing compliance costs across affected sectors, OSHA estimates that annual incremental compliance costs of $361.4 million will result following promulgation of the rule.

The next section applies these estimates of incremental compliance costs for an analysis of the economic impacts of the revised asbestos standard.

F. Economic Impact and Regulatory Flexibility Analysis Introduction

OSHA examined the impacts of compliance costs on payroll, sales and profits for firms in general industry, shipyards and construction affected by the revision to the asbestos standard. OSHA's economic impact analysis is presented below.

Data Sources and Methodology

OSHA used a variety of financial indicators and sources of statistical data to assess the impacts on the affected industries. Payroll data for primary manufacturing industries and real estate industries were taken from County Business Patterns, 1990 [Dept. of Commerce, 1993]. Payroll data for construction industries were taken from the 1987 Census of Construction, [Dept. of Commerce, 1990b]. Data on sales were obtained from Dun and Bradstreet's Marketing Information computer database [Dun and Bradstreet, 1992a] for the following industry groups:

 

  • * Primary asbestos manufacturing;
    * Automotive repair;
    * Shipyards;
    * Selected groups in general industry where the disturbance of asbestos
    during routine maintenance falls under the construction standard;


  •  

 

Selected real estate industries. Data on net value of construction work (a statistic approximating the sales volume of construction firms) for the construction sector were taken from the "1987 Census of Construction" [Dept. of Commerce, 1990b]. OSHA derived pre-tax profit rates using Dun and Bradstreet post-tax return-on-sales data from Dun's Insight computer database [Dun and Bradstreet, 1992b] and the 1987 tax code. Pre-tax profits were calculated using a formula that contains the marginal corporate tax rates for 1993.

Impacts in General Industry and Shipyards

"Primary manufacturing." OSHA has determined that the following four industries in primary manufacturing would be affected by the revision to the asbestos standard: SIC 3292, Friction Materials; SIC 3053, Gaskets and Packings; SIC 2952, Coatings and Sealants; and SIC 3089, Plastics. OSHA has concluded that there will be no incremental costs for the secondary manufacturing industries identified in the preliminary regulatory impact analysis because these manufacturers are believed to have already achieved exposure reductions that bring them into compliance with OSHA's new PEL of 0.1 f/cc.

OSHA compared the incremental compliance costs anticipated for the four affected primary manufacturing industries with three financial indicators: (1) Annual payroll per firm, (2) dollar value of sales per firm and (3) pre-tax profits per firm. The comparison with annual payroll conveys the magnitude of compliance costs relative to labor costs. The comparison with sales provides a measure of the extent to which prices would rise to maintain profit levels if a firm is able to pass 100 percent of incremental costs forward to buyers. If firms, for competitive reasons, are unable to pass costs forward and must instead absorb the full impact internally, pre-tax profits would be expected to fall. The comparison with pre-tax profits thus illustrates the maximum financial impact if the firm absorbs 100 percent of the incremental compliance costs.

Table 11 presents the estimated impact of compliance costs in relation to annual payroll, sales, and pre-tax profits per plant in primary manufacturing. Compliance costs as a percentage of sales are modest, averaging 0.6 percent for affected establishments in primary manufacturing (Column 7). However, as shown in Column 8 in the table, profit impacts are relatively high for two sectors: friction materials (26.2 percent) and gaskets and packings (7.3 percent). For reasons given below, OSHA believes that profit impacts will be minimized by the ability of firms to pass forward costs to consumers. The small increases in product prices (less than 2 percent) necessary to cover the increased costs of production would be unlikely to affect the demand for these products.

Table 11. -- Estimated Economic Impacts in General Industry As
A Result Of The Revision To The General Industry
Asbestos Standard

(For Table 11, see printed copy)

As evidenced by the disappearance of domestic production of various asbestos-based product lines (e.g., A/C pipe and A/C sheet) over the last several years and the dramatic reduction in the production of other products (e.g., asbestos-containing plastics), many former producers and consumers of asbestos are increasingly substituting other materials for asbestos. The market forces behind increased substitution appear to be related to legal issues, such as liability, and regulatory concerns, such as the attempted Environmental Protection Agency asbestos ban, rather than strictly the effect of product substitution. Even when asbestos-based products are much cheaper than non-asbestos-based products, demand and supply are shifting away from asbestos-based products.

Primary manufacturers appear to have the latitude to raise prices on their products in the short run, but may substitute away from asbestos entirely in the long run. In the friction materials industry, substitute products can be difficult to develop, suggesting a limited cross-elasticity of demand that permits costs to be fairly easily passed along to consumers. For other industries, since the substitution of inputs generally occurs at the site of formerly asbestos-based production, any incremental economic impacts from this rule should be minimal.

In accordance with the Regulatory Flexibility Act, OSHA also examined the impacts on small establishments in primary manufacturing to determine if they would be adversely affected by the final standard. Using data for firms with 19 or fewer employees, OSHA compared compliance costs with annual payroll, sales, and pre-tax profits for affected industries identified as containing small establishments. The affected industries include small firms producing asbestos gaskets and packings in SIC 3053, Gaskets, Packing, and Sealing Devices and producing asbestos coatings and sealants in SIC 2952, Asphalt Felts and Coatings. OSHA has determined that there are currently no small producers of asbestos friction materials and asbestos plastics.

Small-firm impacts for primary manufacturing are shown in Table 11. Under a full cost-pass-through scenario, OSHA projects that compliance costs would be 1.1 percent of sales for gaskets and packings and that compliance costs would be 0.6 percent of sales for coatings and sealants. Costs as a percentage of pre-tax profits, shown in the last column of Table 11, are significantly higher, suggesting that severe profit reductions could be felt by any small firms unable to pass forward incremental compliance costs. However, as discussed above, OSHA believes these firms will be able to pass along most of the costs of compliance by raising prices and will therefore suffer minimal economic impact.

"Automotive repair." Economic impacts in establishments performing automotive brake and clutch repair, presented in Table 12, are expected to be minor as a result of compliance with the revised standard for general industry. As a percentage of sales, compliance costs average 0.01 percent for industry overall and for affected small establishments. As for the worst-case financial impact, compliance costs as a percentage of profits would average 0.21 percent for all of industry and would average 0.26 percent for small establishments. On the basis of these impact estimates, OSHA has therefore concluded that overall impacts in automotive repair will be modest and that there will be no significant differential effect on small businesses as a result of the final standard.

Table 12. -- Economic Impacts Resulting From The Revision To The
Asbestos Standard, For Establishments Performing
Brake And Clutch Repair
SIC industry Compliance cost per firm Sales per firm Pre-tax profit Pre- tax profit rate (percent) Compliance costs as a percent of sales Compliance costs as a percent of profits
Average Impacts on all Establishments:
Brake and Clutch Repair:
551 New and Used Car Dealers $34 $9,577,612 $129,551 1.4 0.00(a) 0.03
554 Gasoline Service Stations 34 939,870 23,220 2.5 0.00(a) 0.15
753 Automotive Repair Shops 34 223,065 12,810 5.7 0.02 0.26
  • Averages
34 1,347,958 27,269 4.4 0.01 0.21
Impacts on Small Establishments:
Brake and Clutch Repair:
551 New and Used Car Dealers 34 2,589,089 30,460 1.2 0.00(a) 0.11
554 Gasoline Service Stations 34 669,395 16,538 2.5 0.01 0.21
753 Automotive Repair Shops 34 197,139 11,321 5.7 0.02 0.30
  • Averages
34 467,607 13,916 4.5 0.01 0.26
Sources: U.S. Dept. of Labor, OSHA, Office or Regulatory Analysis; Dun and Brad Department of Commerce, 1993
Footnote(a) Impacts presented as 0.00% are projected to be below 0.01%

"Ship repair." The impacts of the revision to the asbestos standard on establishments involved in ship repair are expected to be minimal. Table 13 shows that average price impacts would be 0.07 percent for all establishments and would be 0.1 percent for small establishments if firms were able to charge increased operating costs to their customers, i.e., ship owners. At the opposite extreme in terms of potential financial impact, compliance costs as a percentage of profits would average 0.8 percent for firms of all sizes in ship repair and would average 1.2 percent for small firms in ship repair. Thus, OSHA has concluded that there will be no significant differential effect on small businesses involved in ship repair as a result of the final standard.

Table 13. -- Economic Impacts On Establishments Performing
Ship repair As A Result Of The Revision To
The Asbestos Standard
SIC industry Compli- ance cost per firm Sales per firm Pre-tax profit Pre-tax profit rate (per- cent) Compliance costs as a percent of sales Compliance costs as a percent of profits
Average Impacts on All Establishments:
Ship Repair:
3731
Shipbuilding and Repair $12,728 $19,439,148 $1,570,840 8.1 0.07 0.81
Impacts on Small Establishments:
Ship Repair:
3731
Shipbuilding and Repair 12,728 12,751,431 1.030,419 8.1 0.10 1.24
Sources: U.S. Dept. of Labor, OSHA, Office of Regulatory Analysis; Dun and Bradstreet 1992a, 1992b; U.S. Department of Commerce, 1993

Impacts Associated With the Revised Construction Standard

"Impacts in the Construction Industry." OSHA estimated economic impacts in construction using three economic impact measures, calculated for each affected industry group. The first measure is the ratio of the average annual compliance cost per affected establishment (or per exposed construction worker) to an estimate of the average payroll per establishment (or per construction worker). As explained above, this measure compares the projected compliance costs to labor costs normally incurred by the establishment.

The second impact measure is the ratio of the average annual compliance cost per affected establishment (or per exposed construction worker) to an estimate of the net dollar value of construction work or sales for an average establishment (or per construction worker). This ratio indicates the relationship of the compliance costs to an establishment or worker's output and indicates the maximum impact on prices assuming 100 percent pass-through of the compliance costs to the consumer.

The third economic impact statistic calculated by OSHA for construction measures the effect of compliance costs on profits. Profit impacts were calculated at the industry level by dividing into compliance costs per establishment, the estimated pre-tax profit per establishment. This index reveals the maximum potential impact on profits under the assumption that compliance costs are fully absorbed by the affected firm. Profit impacts are particularly meaningful when establishments face highly-competitive conditions which prevent the pass-through of compliance costs to customers.

Annual incremental compliance costs per construction firm were estimated using the costs presented above for new construction; asbestos abatement and demolition; general building renovation; routine maintenance in public, commercial, and residential buildings; and custodial work in public, commercial, residential, and industrial buildings (routine maintenance in industrial facilities is analyzed separately below). Table 14 presents average per-worker and per-firm costs and impacts for all affected construction sectors. Table 15 shows estimated costs and impacts for small establishments in affected construction sectors.

Table 14. -- Average Economic Impacts Of The Asbestos
Standard For Construction

[All Establishments, by Industry]

(For Table 14, see printed copy)

Table 15. -- Economic Impacts Of The Revision To The Asbestos
Standard For Construction

[Small Establishments, by Industry]

(For Table 15, see printed copy)

Based on OSHA and CONSAD's estimates of the number of affected firms, crews, and workers performing each construction activity and the number of projects conducted by each firm in a year [OSHA, 1994], annual costs for establishments of average size are expected to range from $190 per building for SIC 6512, Operators of Nonresidential Buildings to $2,283 per firm in SIC 1752, Floor Laying and Other Floor Work, Not Elsewhere Classified.(7) As shown in Table 14, costs as a percentage of payroll, sales, and profits are generally low on both a per-worker and per-establishment basis when averaged across a range of firms in affected industries. Costs as a percentage of sales per establishment average 0.13 percent and do not exceed 0.6 percent in any industry. For the impact scenario where cost pass-through is not possible, OSHA projects that profit reductions would average 2.4 percent and would be below 5 percent for all but one industry, floor laying and floor work. For flooring contractors in SIC 1752, profit impacts could exceed 9 percent if employers were forced to fully absorb compliance costs out of retained revenues and were not able to pass costs forward. OSHA believes, however, that profit impacts will not be as severe as depicted in this worst-case scenario, for two reasons.

__________

Footnote(7) Compliance costs for firms in SICs 6512 and 6513 were estimated on a per-building basis, rather than a per-firm basis, due to insufficient data on numbers of buildings owned per firm in these industry groups.

First, it appears that there are few services that compete with floor maintenance directly, and therefore demand for services provided by the industry is relatively inelastic. Secondly, all floor-laying establishments are treated uniformly by the revised standard. Because no individual firm faces unfair regulatory treatment by the revised standard, cost impacts are expected across the majority of industry. Consequently, most affected firms should be able to pass forward costs to customers without significant redistribution of market share. As indicated in Table 14, cost impacts on prices (sales) would be minimal under a full cost-pass-through scenario.

Annual costs for small establishments are expected to range from $128 per building for SIC 6512, Operators of Nonresidential Buildings to $723 per firm in SIC 1711, Plumbing, Heating and Air-Conditioning, as shown in Table 15, Column 4. Small-firm compliance costs as a percentage of payroll, sales, and profits are fairly modest on both a per-worker and per-establishment basis. Costs as a percentage of sales per establishment average 0.13 percent and do not exceed 0.3 percent in any industry, whereas, for the case of zero cost pass-through, costs as a percentage of profits average 2.4 percent. OSHA has concluded that no differential adverse impact will be experienced by small firms in any construction sector when compared to larger firms because the costs of compliance are expected to be roughly equivalent on a per-worker basis.

"Routine maintenance in industrial facilities." In profiling asbestos maintenance activities within general industry, OSHA and CONSAD have assumed that the majority of the work would be performed by plant and maintenance personnel within the establishment. Under this assumption, incremental costs attributed to requirements in the revised construction standard that pertain to these maintenance tasks would financially impact general industry. Therefore, economic impacts associated with routine maintenance in general industry are included in this section on impacts under the construction standard. Impacts in affected general industry sectors are shown in Tables 16 and 17.

Table 16. -- Average Economic Impacts on the Revision to the
Asbestos Standard for Construction on Establishments
in General Industry Where Routine Asbestos
Maintenance is Performed
SIC Industry Compliance cost per establishment Compliance cost per establishment as a percentage of:
Sales per establishment Pre-tax profits per establishment
2082 Malt Beverages $229 0.00(a) 0(a)
26 Paper Products 3,742 0.02 0.31
28 Chemicals 697 0.00(a) 0.04
29 Petroleum Refining 584 0.00(a) 0.01
321 Flat Glass 651 0.00(a) 0.07
322 Glass and Glassware 651 0.01 0.07
323 Products of Purchased Glass 651 0.02 0.31
331 Steel Works, Blast Furnaces, and Mills 1,036 0.00(a) 0.08
332 Iron and Steel Foundries 1,036 0.01 0.23
34 Fabricated Metal Products 326 0.01 0.12
4813 Telephone Communications 525 0.00(a) 0(a)
4911 Electric Services 1,122 0.00(a) 0.02
493 Comb. Electric, Gas, and Other Utilities 1,300 0.01 0.12
492 Gas Production and Distribution 363 0.00(a) 0.01
4941 Water Supply 264 0.01 0.08
495 Sanitary Services 327 0.01 0.15
  • Averages
897 0.01 0.21
Sources: OSHA, Office of Regulatory Analysis; OSHA, 1994; Dun and Bradstreet, 1992a, 1992b; U.S. Department of Commerce, 1993
Footnote(a) Impacts presented as 0.00% are projected to be below 0.01%
Table 17. -- Economic Impacts of the Revision to the Asbestos
Standard for Construction on Small Establishments
in General Industry Where Routine Asbestos
Maintenance is Performed
SIC Industry Compliance cost per establishment Compliance cost per establishment as a percentage of:
Sales per establishment Pre-tax profits per establishment
2082 Malt Beverages $229 0.01 0.28
26 Paper Products 229 0.01 0.11
28 Chemicals 229 0.01 0.10
29 Petroleum Refining 229 0.00(a) 0.02
321 Flat Glass 229 0.01 0.12
322 Glass and Glassware 229 0.01 0.16
323 Products of Purchased Glass 229 0.04 0.68
331 Steel Works, Blast Furnaces, and Mills 229 0.00(a) 0.06
332 Iron and Steel Foundries 229 0.01 0.11
34 Fabricated Metal Products 229 0.02 0.32
4813 Telephone Communications 496 0.01 0.04
4911 Electric Services 221 0.00(a) 0.03
493 Comb. Electric, Gas, and Other Utilities 221 0.01 0.13
492 Gas Production and Distribution 243 0.00(a) 0.03
4941 Water Supply 243 0.03 0.27
495 Sanitary Service 243 0.04 0.41
Averages 280 0.01 0.21
Sources: U.S. Department of Labor, OSHA, Office of Regulatory Analysis; OSHA, 1994; Dun and Bradstreet, 1992a, 1992b; U.S. Department of Commerce, 1993
Footnote(a) Impacts presented as 0.00% are projected to be below 0.01%

Economic impacts from costs of compliance in industrial facilities were computed in terms of price impacts and profit impacts. As shown in Table 16, average economic impacts across all affected establishments are expected to be minimal. Price impacts -- costs as a percentage of sales -- would average 0.01 percent if firms were able to pass forward all compliance costs to consumers. If full cost pass-through is not achievable and affected firms must finance compliance expenditures from retained earnings, OSHA anticipates that profit impacts would be no greater than 0.21 percent.

Table 17 presents economic impacts on small firms in general industry where routine asbestos maintenance takes place. The results suggest that no serious economic consequences are expected from compliance with the revision to the final rule. Impacts on sales average 0.01 percent, whereas impacts on profits average 0.21 percent and are no higher than 0.7 percent for any industry group. Therefore, OSHA concludes that there will be no significant differential effect on small businesses in general industry performing routine maintenance involving contact with asbestos-containing materials.

Conclusion

In this section OSHA presented economic impact projections for affected industry groups in general industry, shipyards and construction. Economic impact measures calculated by OSHA expressed percentage effects of compliance costs on payroll, sales, and profits. On the basis of OSHA's analysis of the economic effects of the revised asbestos standard, OSHA has determined that impacts will be modest for most affected industry groups. Therefore, OSHA judges the revised asbestos standard to be economically feasible.

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Right-to-Know Rule Options; Estimated Costs. Final Draft. Prepared for:

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Campbell, W.J., R.L. Blake, L.L. Brown, E.E. Cather, and J.J. Sjoberg. [Campbell, 1977] Selected Silicate Minerals and Their Asbestiform Varieties. Mineralogical Definitions and Identification-Characterization. Information Circular 8751, U.S. Department of the Interior, Bureau of Mines. College Park, Md. 1977.

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Cogley, D., N. Krussel, R. McInnes, P. Anderson, and R. Bell. [Cogley, et al., 1982]. Life Cycle of Asbestos in Commercial and Industrial Use Including Estimates of Releases to Air, Water, and Land. Prepared by GCA Corporation, for the U.S. Environmental Protection Agency, Office of Toxic Substances, under Contract No. 68-02-3268. Washington, D.C., February 1982. OSHA Docket H-033c. Exhibit 84-161.

Commission on Merchant Marine and Defense. [Merchant Marine Commission, 1987]. First Report of the Commission on Merchant Marine and Defense, Appendices. Washington, D.C., September 30, 1987.

CONSAD and General Research Corp. [CONSAD and GRC, 1982]. Employer Compensation and Control Systems, Final Report, 1982. Prepared for the U.S. Department of Labor, Occupational Safety and Health Administration. Pittsburgh: Consad Research Corporation; and McLean, Virginia: General Research Corporation, 1982. CONSAD Research Corporation. [CONSAD, 1990]. Economic Analysis of the Proposed Revisions to the OSHA Asbestos Standards for Construction and General Industry. Final Report. Contract Number J-9-F-8-0033, Task Order 4, Option Year 1. July 27, 1990. Docket H-033e, Ex. 8.

CONSAD Research Corporation. [CONSAD, 1985]. Economic and Technological Profile Related to OSHA's Revised Permanent Asbestos Standard for the Construction Industry and Asbestos Removal and Routine Maintenance Projects in General Industry. Final Report. Contract Number J-9-F-4-0024, December 31, 1985. Docket H-033e, Ex. 1-229.

CONSAD Research Corporation and Clayton Environmental Consultants, Inc. [CONSAD, 1984]. Asbestos Task Order for Construction Alternatives. Final Report. Contract Number J-9-F-4-0024, May 25, 1984; Addendum to Final Report, June 14, 1984. Supplement, July 31, 1984. Docket H-033e, Ex. 1-227.

Corn, Mort, Ph.D. [Corn, 1992]. Letter to John Martonik with attached data. School of Hygiene and Public Health, Johns Hopkins University. December 28, 1992. Docket H-033e, Ex. 162-52.

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Asbestos in Public and Commercial Buildings: Supplementary Analyses of Selected Data Previously Considered by the Literature Review Panel. Cambridge, Ma. Docket H-033e, Ex. 162-6a.

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Lexington Books, 1979. Morris, G.E. [RTI, 1982]. Tort Liability and Worker Health: An Examination of the Economic, Legal and Scientific Issues Surrounding the Occupational Disease Protection Afforded by Tort Law, Final Report. Prepared for the U.S. Department of Labor, Occupational Safety and Health Administration, Office of Regulatory Analysis. Research Triangle Park, North Carolina: Research Triangle Institute, 1982.

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National Roofing Contractors Association. [NRCA, 1990]. Comments of the National Roofing Contractors Association to the Occupational Safety and Health Administration regarding the July 20, 1990 Notice of Proposed Rulemaking. November 29, 1990. Docket H-033e, Ex. 7-112.

Prosser, William Lloyd. [Prosser, 1971]. Handbook of the Law of Torts. 4th ed. St. Paul: West Publishing Company, 1971. Rea, S.A. Jr. [Rea, 1981]. "Workmen's Compensation and Occupational Safety under Imperfect Information". Am Econ Rev 71:80-93, March 1981.

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Young, L.R. [Young, 1983]. "Job-Related Disease Case Refused". Journal of Commerce: April 19, 1983.

V. Clearance of Information Collection Requirements

5 CFR 1320 sets forth procedures for agencies to follow in obtaining OMB clearance for information collection requirements under the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. The final Asbestos standard requires the employer to allow OSHA access to records and under certain circumstances, requires employers to submit notifications to the Agency. OMB has reviewed and approved the collection of information requirements for occupational exposure to Asbestos for Construction (29 CFR 1926.1101) and Shipyards (29 CFR 1915.1001) under OMB clearance numbers 1218-0134 and 1218-0195 respectively. The OMB clearances expire in July 1997. There were no new information collection requirements for General industry 29 CFR 1910.1001, currently approved under 1218-0133. The Asbestos General industry clearance expires in March 1996.

VI. Authority and Signature

This document was prepared under the direction of Joseph A. Dear, Assistant Secretary of Labor for Occupational Safety and Health, U.S. Department of Labor, 200 Constitution Avenue, NW., Washington, DC 20210.

Accordingly, pursuant to sections 4, 6(b), 8(c), and 8(g) of the Occupational Safety and Health Act of 1970 (29 U.S.C. 653, 655, 657); Sec. 107, Contract Work Hours and Safety Standards Act (Construction Safety Act, 40 U.S.C. 333); Sec. 41, Longshore and Harbor Workers' Compensation Act (33 U.S.C. 941); and 29 CFR Part 1911; 29 CFR Part 1910, 1915 and 1926 are amended as set forth below.

List of Subjects in 29 CFR Part 1910, 1915 and 1926

Asbestos, Cancer, Carcinogen, Construction industry, Health, Hazardous materials, Labeling, Occupational Safety and Health, Protective Equipment, Respiratory Protection, Signs and symbols.

Signed at Washington, DC this 20th day of July, 1994.

Joseph A. Dear
Assistant Secretary of Labor for Occupational Safety and Health.

VII. Amended Standards: Regulatory Text

OSHA hereby amends 29 CFR Parts 1910, 1915 and 1926 as follows:

PART 1910 -- OCCUPATIONAL SAFETY AND HEALTH STANDARDS

1. The authority citation of Subpart B of Part 1910 continues to read:

Authority: Secs. 4, 6 and 8 of the Occupational Safety and Health Act, 29 U.S.C. 653, 655, 657; Walsh-Healey Act, 41 U.S.C. 35 et seq; Service Contract Act of 1965, 41 U.S.C. 351 et seq; sec. 107, Contract Work Hours and Safety Standards Act (Construction Safety Act), 40 U.S.C. 333; sec. 41, Longshore and Harbor Workers' Compensation Act, 33 U.S.C. 941; National Foundation of Arts and Humanities Act, 20 U.S.C. 951 et seq.; Secretary of Labor's Order Nos. 12-71 (36 FR 8754), 8-76 (41 FR 1911), 9-83 (48 FR 35736), or 1-90 (55 FR 9033) as applicable.

1a. Paragraph (a) of Sec. 1910.19 is revised to read as follows:

1910.19. Special provisions for air contaminants.

(a) Asbestos, tremolite, anthophyllite, and actinolite dust. Section 1910.1001 shall apply to the exposure of every employee to asbestos, tremolite, anthophyllite, and actinolite dust in every employment and place of employment covered by Sec. 1910.16, in lieu of any different standard on exposure to asbestos, tremolite, anthophyllite, and actinolite dust which would otherwise be applicable by virtue of any of those sections.

* * * * *

2. The authority citation of subpart Z of 29 CFR part 1910 continues to read as follows:

Authority: Secs 6, 8 Occupational Safety and Health Act, 29 U.S.C. 655, 657: Secretary of Labor's Order 12-71 (36 FR 8754), 9-76 (41 FR 25059), 9-83 [48 FR 35736] or 1-90 (55 FR 9033), as applicable; and 29 CFR part 1911.

All of subpart Z issued under section 6(b) of the Occupational Safety and Health Act, except those substances which have exposure limits listed in Tables Z-1, Z-2 and Z-3 of 29 CFR 1910.1000. The latter were issued under section 6(a) [29 U.S.C. 655(a)].

Section 1910.1000, Tables Z-1, Z-2 and Z-3 also issued under 5 U.S.C. 553. Section 1910.1000, Tables Z-1, Z-1 and Z-3 not issued under 29 CFR part 1911 except for the arsenic (organic compounds), benzene, and cotton dust listings.

Section 1910.1001 also issued under section 107 of Contract Work Hours and Safety Standards Act, 40 U.S.C. 333.

Section 1910.1002 not issued under 29 U.S.C. or 29 CFR part 1911; also issued under 5 U.S.C. 653.

Section 1910.1003 through 1910.1018 also issued under 29 CFR 653.

Section 1910.1025 also issued under 29 U.S.C. 653 and 5 U.S.C. 553.

Section 1910.1028 also issued under 29 U.S.C. 653.

Section 1910.1030 also issued under 29 U.S.C. 653.

Section 1910.1043 also issued under 5 U.S.C. 551 et seq.

Section 1910.1045 and 1910.1047 also issued under 29 U.S.C. 653. Section 1910.1048 also issued under 29 U.S.C. 653.

Sections 1910.1200, 1910.1499 and 1910.1500 also issued under 5 U.S.C.

553.

Section 1910.1450 is also issued under sec. 6(b), 8(c) and 8(g)(2), Pub. L. 91-596, 84 Stat. 1593, 1599, 1600; 29 U.S.C. 655, 657.

3. Section 1910.1001 is amended by revising paragraphs (a) through (p) (all the text preceding the appendices) to read as follows:

1910.1001 Asbestos.

(a) Scope and application. (1) This section applies to all occupational exposures to asbestos in all industries covered by the Occupational Safety and Health Act, except as provided in paragraph (a)(2) and (3) of this section.

(2) This section does not apply to construction work as defined in 29 CFR 1910.12(b). (Exposure to asbestos in construction work is covered by 29 CFR 1926.58.) (3) This section does not apply to ship repairing, shipbuilding and shipbreaking employments and related employments as defined in 29 CFR 1915.4. (Exposure to asbestos in these employments is covered by 29 CFR 1915.191).

(b) Definitions. "Asbestos" includes chrysotile, amosite, crocidolite, tremolite asbestos, anthophyllite asbestos, actinolite asbestos, and any of these minerals that have been chemically treated and/or altered.

"Asbestos-containing material (ACM)" means any material containing more than 1% asbestos.

"Assistant Secretary" means the Assistant Secretary of Labor for Occupational Safety and Health, U.S. Department of Labor, or designee.

"Authorized person" means any person authorized by the employer and required by work duties to be present in regulated areas.

"Building/facility owner" is the legal entity, including a lessee, which exercises control over management and record keeping functions relating to a building and/or facility in which activities covered by this standard take place.

"Director" means the Director of the National Institute for Occupational Safety and Health, U.S. Department of Health and Human Services, or designee.

"Employee exposure" means that exposure to airborne asbestos that would occur if the employee were not using respiratory protective equipment.

"Fiber" means a particulate form of asbestos 5 micrometers or longer,with a length-to-diameter ratio of at least 3 to 1.

"High-efficiency particulate air (HEPA) filter" means a filter capable of trapping and retaining at least 99.97 percent of 0.3 micrometer diameter mono-disperse particles.

"Industrial hygienist" means a professional qualified by education, training, and experience to anticipate, recognize, evaluate and develop controls for occupational health hazards.

"PACM" means thermal system insulation, sprayed on or troweled on surfacing material and debris in work areas where such material is present.

"Regulated area" means an area established by the employer to demarcate areas where airborne concentrations of asbestos exceed, or there is a reasonable possibility they may exceed, the permissible exposure limits.

(c) Permissible exposure limit (PELS) -- (1) Time-weighted average limit (TWA). The employer shall ensure that no employee is exposed to an airborne concentration of asbestos excess of 0.1 fiber per cubic centimeter of air as an eight (8)-hour time-weighted average (TWA) as determined by the method prescribed in Appendix A of this section, or by an equivalent method.

(2) Excursion limit. The employer shall ensure that no employee is exposed to an airborne concentration of asbestos in excess of 1.0 fiber per cubic centimeter of air (1 f/cc) as averaged over a sampling period of thirty (30) minutes.

(d) Exposure monitoring. -- (1) General. (i) Determinations of employee exposure shall be made from breathing zone air samples that are representative of the 8-hour TWA and 30-minute short-term exposures of each employee.

(ii) Representative 8-hour TWA employee exposures shall be determined on the basis of one or more samples representing full-shift exposures for each shift for each employee in each job classification in each work area. Representative 30-minute short-term employee exposures shall be determined on the basis of one or more samples representing 30 minute exposures associated with operations that are most likely to produce exposures above the excursion limit for each shift for each job classification in each work area.

(2) Initial monitoring. (i) Each employer who has a workplace or work operation covered by this standard, except as provided for in paragraphs (d)(2)(ii) and (d)(2)(iii) of this section, shall perform initial monitoring of employees who are, or may reasonably be expected to be exposed to airborne concentrations at or above the TWA permissible exposure limit and/or excursion limit.

(ii) Where the employer has monitored after March 31, 1992, for the TWA permissible exposure limit and/or the excursion limit, and the monitoring satisfies all other requirements of this section, the employer may rely on such earlier monitoring results to satisfy the requirements of paragraph (d)(2)(i) of this section.

(iii) Where the employer has relied upon objective data that demonstrate that asbestos is not capable of being released in airborne concentrations at or above the TWA permissible exposure limit and/or excursion limit under the expected conditions of processing, use, or handling, then no initial monitoring is required.

(3) Monitoring frequency (periodic monitoring) and patterns. After the initial determinations required by paragraph (d)(2)(i) of this section, samples shall be of such frequency and pattern as to represent with reasonable accuracy the levels of exposure of the employees. In no case shall sampling be at intervals greater than six months for employees whose exposures may reasonably be foreseen to exceed the TWA permissible exposure limit and/or excursion limit.

(4) Changes in monitoring frequency. If either the initial or the periodic monitoring required by paragraphs (d)(2) and (d)(3) of this section statistically indicates that employee exposures are below the TWA permissible exposure limit and/or excursion limit, the employer may discontinue the monitoring for those employees whose exposures are represented by such monitoring.

(5) Additional monitoring. Notwithstanding the provisions of paragraphs (d)(2)(ii) and (d)(4) of this section, the employer shall institute the exposure monitoring required under paragraphs (d)(2)(i) and (d)(3) of this section whenever there has been a change in the production, process, control equipment, personnel or work practices that may result in new or additional exposures above the TWA permissible exposure limit and/or excursion limit or when the employer has any reason to suspect that a change may result in new or additional exposures above the action level and/or excursion limit.

(6) Method of monitoring. (i) All samples taken to satisfy the monitoring requirements of paragraph (d) of this section shall be personal samples collected following the procedures specified in Appendix A.

(ii) All samples taken to satisfy the monitoring requirements of paragraph (d) of this section shall be evaluated using the OSHA Reference Method (ORM) specified in Appendix A of this section, or an equivalent counting method.

(iii) If an equivalent method to the ORM is used, the employer shall ensure that the method meets the following criteria:

(A) Replicate exposure data used to establish equivalency are collected in side-by-side field and laboratory comparisons; and

(B) The comparison indicates that 90% of the samples collected in the range 0.5 to 2.0 times the permissible limit have an accuracy range of plus or minus 25 percent of the ORM results at a 95% confidence level as demonstrated by a statistically valid protocol; and

(C) The equivalent method is documented and the results of the comparison testing are maintained.

(iv) To satisfy the monitoring requirements of paragraph (d) of this section, employers must use the results of monitoring analysis performed by laboratories which have instituted quality assurance programs that include the elements as prescribed in Appendix A of this section.

(7) Employee notification of monitoring results. (i) The employer shall, within 15 working days after the receipt of the results of any monitoring performed under the standard, notify the affected employees of these results in writing either individually or by posting of results in an appropriate location that is accessible to affected employees.

(ii) The written notification required by paragraph (d)(7)(i) of this section shall contain the corrective action being taken by the employer to reduce employee exposure to or below the TWA and/or excursion limit, wherever monitoring results indicated that the TWA and/or excursion limit had been exceeded.

(e) Regulated Areas. -- (1) Establishment. The employer shall establish regulated areas wherever airborne concentrations of asbestos and/or PACM are in excess of the TWA and/or excursion limit prescribed in paragraph (c) of this section.

(2) Demarcation. Regulated areas shall be demarcated from the rest of the workplace in any manner that minimizes the number of persons who will be exposed to asbestos.

(3) Access. Access to regulated areas shall be limited to authorized persons or to persons authorized by the Act or regulations issued pursuant thereto.

(4) Provision of respirators. Each person entering a regulated area shall be supplied with and required to use a respirator, selected in accordance with paragraph (g)(2) of this section.

(5) Prohibited activities. The employer shall ensure that employees do not eat, drink, smoke, chew tobacco or gum, or apply cosmetics in the regulated areas.

(f) Methods of compliance. -- (1) Engineering controls and work practices. (i) The employer shall institute engineering controls and work practices to reduce and maintain employee exposure to or below the TWA and/or excursion limit prescribed in paragraph (c) of this section, except to the extent that such controls are not feasible.

(ii) Wherever the feasible engineering controls and work practices that can be instituted are not sufficient to reduce employee exposure to or below the TWA and/or excursion limit prescribed in paragraph (c) of this section, the employer shall use them to reduce employee exposure to the lowest levels achievable by these controls and shall supplement them by the use of respiratory protection that complies with the requirements of paragraph (g) of this section.

(iii) For the following operations, wherever feasible engineering controls and work practices that can be instituted are not sufficient to reduce the employee exposure to or below the TWA and/or excursion limit prescribed in paragraph (c) of this section, the employer shall use them to reduce employee exposure to or below 0.5 fiber per cubic centimeter of air (as an eight-hour time-weighted average) or 2.5 fibers/cc for 30 minutes (short-term exposure) and shall supplement them by the use of any combination of respiratory protection that complies with the requirements of paragraph (g) of this section, work practices and feasible engineering controls that will reduce employee exposure to or below the TWA and to or below the excursion limit permissible prescribed in paragraph (c) of this section: Coupling cutoff in primary asbestos cement pipe manufacturing; sanding in primary and secondary asbestos cement sheet manufacturing; grinding in primary and secondary friction product manufacturing; carding and spinning in dry textile processes; and grinding and sanding in primary plastics manufacturing.

(iv) Local exhaust ventilation. Local exhaust ventilation and dust collection systems shall be designed, constructed, installed, and maintained in accordance with good practices such as those found in the American National Standard Fundamentals Governing the Design and Operation of Local Exhaust Systems, ANSI Z9.2-1979.

(v) Particular tools. All hand-operated and power-operated tools which would produce or release fibers of asbestos, such as, but not limited to, saws, scorers, abrasive wheels, and drills, shall be provided with local exhaust ventilation systems which comply with paragraph (f)(1)(iv) of this section.

(vi) Wet methods. Insofar as practicable, asbestos shall be handled, mixed, applied, removed, cut, scored, or otherwise worked in a wet state sufficient to prevent the emission of airborne fibers so as to expose employees to levels in excess of the TWA and/or excursion limit, prescribed in paragraph (c) of this section, unless the usefulness of the product would be diminished thereby.

(vii) [Reserved] (viii) Particular products and operations. No asbestos cement, mortar, coating, grout, plaster, or similar material containing asbestos, shall be removed from bags, cartons, or other containers in which they are shipped, without being either wetted, or enclosed, or ventilated so as to prevent effectively the release of airborne fibers of.

(ix) Compressed air. Compressed air shall not be used to remove asbestos or materials containing asbestos unless the compressed air is used in conjunction with a ventilation system which effectively captures the dust cloud created by the compressed air.

(x) Flooring. Sanding of asbestos-containing flooring material is prohibited.

(2) Compliance program. (i) Where the TWA and/or excursion limit is exceeded, the employer shall establish and implement a written program to reduce employee exposure to or below the TWA and to or below the excursion limit by means of engineering and work practice controls as required by paragraph (f)(1) of this section, and by the use of respiratory protection where required or permitted under this section.

(ii) Such programs shall be reviewed and updated as necessary to reflect significant changes in the status of the employer's compliance program.

(iii) Written programs shall be submitted upon request for examination and copying to the Assistant Secretary, the Director, affected employees and designated employee representatives.

(iv) The employer shall not use employee rotation as a means of compliance with the TWA and/or excursion limit. (3) Specific compliance methods for brake and clutch repair:

(i) Engineering controls and work practices for brake and clutch repair and service. During automotive brake and clutch inspection, disassembly, repair and assembly operations, the employer shall institute engineering controls and work practices to reduce employee exposure to materials containing asbestos using a negative pressure enclosure/HEPA vacuum system method or low pressure/wet cleaning method, which meets the detailed requirements set out in Appendix F to this section. The employer may also comply using an equivalent method which follows written procedures which the employer demonstrates can achieve results equivalent to Method A in Appendix F to this section. For facilities in which no more than 5 pair of brakes or 5 clutches are inspected, disassembled, repaired, or assembled per week, the method set forth in paragraph [D] of Appendix F of this section may be used.

(ii) The employer may also comply by using an equivalent method which follows written procedures, which the employer demonstrates can achieve equivalent exposure reductions as do the two "preferred methods." Such demonstration must include monitoring data conducted under workplace conditions closely resembling the process, type of asbestos containing materials, control method, work practices and environmental conditions which the equivalent method will be used, or objective data, which document that under all reasonably foreseeable conditions of brake and clutch repair applications, the method results in exposures which are equivalent to the methods set out in Appendix F to this section.

(g) Respiratory protection -- (1) General. The employer shall provide respirators, and ensure that they are used, where required by this section. Respirators shall be used in the following circumstances:

(i) During the interval necessary to install or implement feasible engineering and work practice controls;

(ii) In work operations, such as maintenance and repair activities, or other activities for which engineering and work practice controls are not feasible;

(iii) In work situations where feasible engineering and work practice controls are not yet sufficient to reduce exposure to or below the TWA and/or excursion limit; and

(iv) In emergencies. (2) Respirator selection. (i) Where respirators are required under this section, the employer shall select and provide, at no cost to the employee, the appropriate respirator as specified in Table 1. The employer shall select respirators from among those jointly approved as being acceptable for protection by the Mine Safety and Health Administration (MSHA) and by the National Institute for Occupational Safety and Health (NIOSH) under the provisions of 30 CFR Part 11.

(ii) The employer shall provide a powered, air-purifying respirator in lieu of any negative pressure respirator specified in Table 1 whenever:

(A) An employee chooses to use this type of respirator; and

(B) This respirator will provide adequate protection to the employee.

Table 1. -- Respiratory Protection for Asbestos Fibers
Airborne concentration of asbestos or conditions of use Required respirator
Not in excess of 1 f/cc (10) X PEL), or otherwise as required independent of exposure pursuant to (h)(2)(iv) Half-mask air purifying respirator other than a disposable respirator, equipped with high efficiency filters
Not in excess of 5 f/cc (50 X PEL) Full facepiece air-purifying respirator equipped with high efficiency filters
Not in excess of 10 f/cc (100 X PEL) Any powered air-purifying respirator equipped with high efficiency filters or any supplied air respirator operated in continuous flow mode
Not in excess of 100 f/cc (1,000 X PEL) Full facepiece supplied air respirator operated in pressure demand mode
Greater than 100 f/cc (1,000 X PEL) or unknown concentration Full facepiece supplied air respirator operated in pressure demand mode, equipped with an auxiliary positive pressure self-contained breathing apparatus

Note: a. Respirators assigned for high environmental concentrations may be used at lower concentrations, or when required respirator use is independent of concentration.

b. A high efficiency filter means a filter that is at least 99.97 percent efficient against mono-dispersed particles of 0.3 micrometers in diameter or larger.

(3) Respirator program. (i) Where respiratory protection is required, the employer shall institute a respirator program in accordance with 29 CFR 1910.134(b), (d), (e), and (f).

(ii) The employer shall permit each employee who uses a filter respirator to change the filter elements whenever an increase in breathing resistance is detected and shall maintain an adequate supply of filter elements for this purpose.

(iii) Employees who wear respirators shall, be permitted to leave the regulated area to wash their faces and respirator facepieces whenever necessary to prevent skin irritation associated with respirator use.

(iv) No employee shall be assigned to tasks requiring the use of respirators if, based upon his or her most recent examination, an examining physician determines that the employee will be unable to function normally wearing a respirator, or that the safety or health of the employee or other employees will be impaired by the use of a respirator. Such employee shall be assigned to another job or given the opportunity to transfer to a different position whose duties he or she is able to perform with the same employer, in the same geographical area and with the same seniority, status, and rate of pay the employee had just prior to such transfer, if such a different position is available.

(4) Respirator fit testing. (i) The employer shall ensure that the respirator issued to the employee exhibits the least possible facepiece leakage and that the respirator is fitted properly.

(ii) For each employee wearing negative pressure respirators, employers shall perform either quantitative or qualitative face fit tests at the time of initial fitting and at least every six months thereafter. The qualitative fit tests may be used only for testing the fit of half-mask respirators where they are permitted to be worn, and shall be conducted in accordance with Appendix C of this section. The tests shall be used to select facepieces that provide the required protection as prescribed in Table 1, in paragraph (g)(2)(ii) of this section.

(h) Protective work clothing and equipment -- (1) Provision and use. If an employee is exposed to asbestos above the TWA and/or excursion limit, or where the possibility of eye irritation exists, the employer shall provide at no cost to the employee and ensure that the employee uses appropriate protective work clothing and equipment such as, but not limited to:

(i) Coveralls or similar full-body work clothing;

(ii) Gloves, head coverings, and foot coverings; and

(iii) Face shields, vented goggles, or other appropriate protective equipment which complies with 1910.133 of this Part.

(2) Removal and storage. (i) The employer shall ensure that employees remove work clothing contaminated with asbestos only in change rooms provided in accordance with paragraph (i)(1) of this section.

(ii) The employer shall ensure that no employee takes contaminated work clothing out of the change room, except those employees authorized to do so for the purpose of laundering, maintenance, or disposal.

(iii) Contaminated work clothing shall be placed and stored in closed containers which prevent dispersion of the asbestos outside the container.

(iv) Containers of contaminated protective devices or work clothing which are to be taken out of change rooms or the workplace for cleaning, maintenance or disposal, shall bear labels in accordance with paragraph(j)(2) of this section.

(3) Cleaning and replacement. (i) The employer shall clean, launder, repair, or replace protective clothing and equipment required by this paragraph to maintain their effectiveness. The employer shall provide clean protective clothing and equipment at least weekly to each affected employee.

(ii) The employer shall prohibit the removal of asbestos from protective clothing and equipment by blowing or shaking. (iii) Laundering of contaminated clothing shall be done so as to prevent the release of airborne fibers of asbestos in excess of the permissible exposure limits prescribed in paragraph (c) of this section.

(iv) Any employer who gives contaminated clothing to another person for laundering shall inform such person of the requirement in paragraph (h)(3)(iii) of this section to effectively prevent the release of airborne fibers of asbestos in excess of the permissible exposure limits.

(v) The employer shall inform any person who launders or cleans protective clothing or equipment contaminated with asbestos of the potentially harmful effects of exposure to asbestos.

(vi) Contaminated clothing shall be transported in sealed impermeable bags, or other closed, impermeable containers, and labeled in accordance with paragraph (j) of this section.

(i) Hygiene facilities and practices -- (1) Change rooms. (i) The employer shall provide clean change rooms for employees who work in areas where their airborne exposure to asbestos is above the TWA and/or excursion limit.

(ii) The employer shall ensure that change rooms are in accordance with 1910.141(e) of this part, and are equipped with two separate lockers or storage facilities, so separated as to prevent contamination of the employee's street clothes from his protective work clothing and equipment.

(2) Showers. (i) The employer shall ensure that employees who work in areas where their airborne exposure is above the TWA and/or excursion limit shower at the end of the work shift.

(ii) The employer shall provide shower facilities which comply with 1910.141(d)(3) of this part.

(iii) The employer shall ensure that employees who are required to shower pursuant to paragraph (i)(2)(i) of this section do not leave the workplace wearing any clothing or equipment worn during the work shift.

(3) Lunchrooms. (i) The employer shall provide lunchroom facilities for employees who work in areas where their airborne exposure is above the TWA and/or excursion limit.

(ii) The employer shall ensure that lunchroom facilities have a positive pressure, filtered air supply, and are readily accessible to employees.

(iii) The employer shall ensure that employees who work in areas where their airborne exposure is above the PEL and/or excursion limit wash their hands and faces prior to eating, drinking or smoking.

(iv) The employer shall ensure that employees do not enter lunchroom facilities with protective work clothing or equipment unless surface asbestos fibers have been removed from the clothing or equipment by vacuuming or other method that removes dust without causing the asbestos to become airborne.

(4) Smoking in work areas. The employer shall ensure that employees do not smoke in work areas where they are occupationally exposed to asbestos because of activities in that work area.

(j) Communication of hazards to employees -- Introduction. This section applies to the communication of information concerning asbestos hazards in general industry to facilitate compliance with this standard. Asbestos exposure in general industry occurs in a wide variety of industrial and commercial settings. Employees who manufacture asbestos-containing products may be exposed to asbestos fibers. Employees who repair and replace automotive brakes and clutches may be exposed to asbestos fibers. In addition, employees engaged in housekeeping activities in industrial facilities with asbestos product manufacturing operations, and in public and commercial buildings with installed asbestos containing materials may be exposed to asbestos fibers. Most of these workers are covered by this general industry standard, with the exception of state or local governmental employees in non-state plan states. It should be noted that employees who perform housekeeping activities during and after construction activities are covered by the asbestos construction standard, 29 CFR 1926.1101, formerly 1926.58). However, housekeeping employees, regardless of industry designation, should know whether building components they maintain may expose them to asbestos. The same hazard communication provisions will protect employees who perform housekeeping operations in all three asbestos standards; general industry, construction, and shipyard employment. As noted in the construction standard, building owners are often the only and/or best source of information concerning the presence of previously installed asbestos containing building materials. Therefore they, along with employers of potentially exposed employees, are assigned specific information conveying and retention duties under this section.

(1) Installed Asbestos Containing Material. Employers and building owners are required to treat installed TSI and sprayed on and troweled- on surfacing materials as ACM for purposes of this standard. These materials are designated "presumed ACM or PACM", and are defined in paragraph (B) of this standard. Asphalt and vinyl flooring material installed no later than 1980 also must be treated as asbestos- containing. The employer or building owner may demonstrate that PACM and flooring material do not contain asbestos by complying with paragraph (j)(6) of this section.

(2) Duties of employers and building and facility owners. (i) Employers and building and facility owners shall exercise due diligence in complying with these requirements to inform employers and employees about the presence and location of ACM and PACM.

(ii) Building and facility owners shall maintain records of all information required to be provided pursuant to this section and/or otherwise known to the building owner concerning the presence, location and quantity of ACM and PACM in the building/facility. Such records shall be kept for the duration of ownership and shall be transferred to successive owners.

(iii) Building and facility owners shall inform employers of employees, and employers shall inform employees who will perform housekeeping activities in areas which contain ACM and/or PACM of the presence and location of ACM and PACM in such areas. Identification of ACM and PACM shall be made by an industrial hygienists or by persons whose skill and experience with respect to identification of asbestos hazards, is the equivalent to that of industrial hygienists and so can be demonstrated by the owner.

(3) Warning signs. (i) Posting. Warning signs shall be provided and displayed at each regulated area. In addition, warning signs shall be posted at all approaches to regulated areas so that an employee may read the signs and take necessary protective steps before entering the area.

(ii) Sign specifications. The warning signs required by paragraph (j)(1)(i) of this section shall bear the following information:

DANGER

ASBESTOS

CANCER AND LUNG DISEASE HAZARD

AUTHORIZED PERSONNEL ONLY

RESPIRATORS AND PROTECTIVE CLOTHING

ARE REQUIRED IN THIS AREA

(iii) [Reserved] (iv) The employer shall ensure that employees working in and contiguous to regulated areas comprehend the warning signs required to be posted by paragraph (j)(1)(i) of this section. Means to ensure employee comprehension may include the use of foreign languages, pictographs and graphics.

(4) Warning labels. (i) Labeling. Warning labels shall be affixed to all raw materials, mixtures, scrap, waste, debris, and other products containing asbestos fibers, or to their containers.

(ii) Label specifications. The labels shall comply with the requirements of 29 CFR 1910.1200(f) of OSHA's Hazard Communication standard, and shall include the following information:

DANGER

CONTAINS ASBESTOS FIBERS

AVOID CREATING DUST

CANCER AND LUNG DISEASE HAZARD

(5) Material safety data sheets. Employers who are manufacturers or importers of asbestos or asbestos products shall comply with the requirements regarding development of material safety data sheets as specified in 29 CFR 1910.1200(g) of OSHA's Hazard Communication standard, except as provided by paragraph (j)(4) of this section.

(6) The provisions for labels required by paragraph (j)(2) of this section or for material safety data sheets required by paragraph (j)(5) of this section do not apply where:

(i) Asbestos fibers have been modified by a bonding agent, coating, binder, or other material provided that the manufacturer can demonstrate that during any reasonably foreseeable use, handling, storage, disposal, processing, or transportation, no airborne concentrations of fibers of asbestos in excess of the TWA permissible exposure level and/or excursion limit will be released or (ii) Asbestos is present in a product in concentrations less than 1.0%. (7) Employee information and training. (i) The employer shall institute a training program for all employees who are exposed to airborne concentrations of asbestos at or above the PEL and/or excursion limit and ensure their participation in the program.

(ii) Training shall be provided prior to or at the time of initial assignment and at least annually thereafter.

(iii) The training program shall be conducted in a manner which the employee is able to understand. The employer shall ensure that each employee is informed of the following:

(A) The health effects associated with asbestos exposure;

(B) The relationship between smoking and exposure to asbestos producing lung cancer:

(C) The quantity, location, manner of use, release, and storage of asbestos, and the specific nature of operations which could result in exposure to asbestos;

(D) The engineering controls and work practices associated with the employee's job assignment;

(E) The specific procedures implemented to protect employees from exposure to asbestos, such as appropriate work practices, emergency and clean-up procedures, and personal protective equipment to be used;

(F) The purpose, proper use, and limitations of respirators and protective clothing, if appropriate;

(G) The purpose and a description of the medical surveillance program required by paragraph (l) of this section;

(H) The content of this standard, including appendices. (I) The names, addresses and phone numbers of public health organizations which provide information, materials, and/or conduct programs concerning smoking cessation. The employer may distribute the list of such organizations contained in Appendix I to this section, to comply with this requirement.

(J) The requirements for posting signs and affixing labels and the meaning of the required legends for such signs and labels.

(iv) The employer shall also provide, at no cost to employees who perform housekeeping operations in a facility which contains ACM or PACM, an asbestos awareness training course, which shall at a minimum contain the following elements: health effects of asbestos, locations of ACM and PACM in the building/facility, recognition of ACM and PACM damage and deterioration, requirements in this standard relating to housekeeping, and proper response to fiber release episodes, to all employees who are or will work in areas where ACM and/or PACM is present. Each such employee shall be so trained at least once a year.

(v) Access to information and training materials. (A) The employer shall make a copy of this standard and its appendices readily available without cost to all affected employees.

(B) The employer shall provide, upon request, all materials relating to the employee information and training program to the Assistant Secretary and the training program to the Assistant Secretary and the Director.

(C) The employer shall inform all employees concerning the availability of self-help smoking cessation program material. Upon employee request, the employer shall distribute such material, consisting of NIH Publication No. 89-1647, or equivalent self-help material, which is approved or published by a public health organization listed in Appendix I to this section.

(8) Criteria to rebut the designation of installed material as PACM. (i) At any time, an employer and/or building owner may demonstrate, for purposes of this standard, that PACM does not contain asbestos. Building owners and/or employers are not required to communicate information about the presence of building material for which such a demonstration pursuant to the requirements of paragraph (j)(8)(ii) of this section has been made. However, in all such cases, the information, data and analysis supporting the determination that PACM does not contain asbestos, shall be retained pursuant to paragraph (n) of this section.

(ii) An employer or owner may demonstrate that PACM does not contain asbestos by the following:

(A) Having a completed inspection conducted pursuant to the requirements of AHERA (40 CFR 763, Subpart E) which demonstrates that no asbestos is present in the material;

(B) Performing tests of the material containing PACM which demonstrate that no asbestos is present in the material. Such tests shall include analysis of 3 bulk samples of each homogeneous area of PACM collected in a randomly distributed manner. The tests, evaluation and sample collection shall be conducted by an accredited inspector or by a CIH. Analysis of samples shall be performed by persons or laboratories with proficiency demonstrated by current successful participation in a nationally recognized testing program such as the National Voluntary Laboratory Accreditation Program (NVLAP) of the National Institute for Standards and Technology (NIST) of the Round Robin for bulk samples administered by the American Industrial Hygiene Association (AIHA) or an equivalent nationally-recognized round robin testing program.

(iii) The employer and/or building owner may demonstrate that flooring material including associated mastic and backing does not contain asbestos, by a determination of an industrial hygienist based upon recognized analytical techniques showing that the material is asbestos free.

(k) Housekeeping. (1) All surfaces shall be maintained as free as practicable of accumulations of dusts and waste containing asbestos.

(2) All spills and sudden releases of material containing asbestos shall be cleaned up as soon as possible.

(3) Surfaces contaminated with asbestos may not be cleaned by the use of compressed air.

(4) Vacuuming. HEPA-filtered vacuuming equipment shall be used for vacuuming. The equipment shall be used and emptied in a manner which minimizes the reentry of asbestos into the workplace.

(5) Shoveling, dry sweeping and dry clean-up of asbestos may be used only where vacuuming and/or wet cleaning are not feasible.

(6) Waste disposal. Waste, scrap, debris, bags, containers, equipment, and clothing contaminated with asbestos consigned for disposal, shall be collected, recycled and disposed of in sealed impermeable bags, or other closed, impermeable containers.

(7) Care of asbestos-containing flooring material. (i) Sanding of asbestos-containing floor material is prohibited. (ii) Stripping of finishes shall be conducted using low abrasion pads at speed lower than 300 rpm and wet methods.

(iii) Burnishing or dry buffing may be performed only on asbestos- containing flooring which has sufficient finish so that the pad cannot contact the asbestos-containing material.

(iv) Dust and debris in an area containing TSI or surfacing ACM/ PACM or visibly deteriorated ACM, shall not be dusted or swept dry, or vacuumed without using a HEPA filter.

(1) Medical surveillance -- (1) General -- (i) Employees covered. The employer shall institute a medical surveillance program for all employees who are or will be exposed to airborne concentrations of fibers of asbestos at or above the TWA and/or excursion limit.

(ii) Examination by a physician. (A) The employer shall ensure that all medical examinations and procedures are performed by or under the supervision of a licensed physician, and shall be provided without cost to the employee and at a reasonable time and place.

(B) Persons other than licensed physicians, who administer the pulmonary function testing required by this section, shall complete a training course in spirometry sponsored by an appropriate academic or professional institution.

(2) Pre-placement examinations. (i) Before an employee is assigned to an occupation exposed to airborne concentrations of asbestos fibers at or above the TWA and/or excursion limit, a pre-placement medical examination shall be provided or made available by the employer.

(ii) Such examination shall include, as a minimum, a medical and work history; a complete physical examination of all systems with emphasis on the respiratory system, the cardiovascular system and digestive tract; completion of the respiratory disease standardized questionnaire in Appendix D, Part 1; a chest roentgenogram (posterior- anterior 14 x 17 inches); pulmonary function tests to include forced vital capacity (FVC) and forced expiratory volume at 1 second (FEV(1.0)); and any additional tests deemed appropriate by the examining physician. Interpretation and classification of chest roentgenogram shall be conducted in accordance with Appendix E to this section.

(3) Periodic examinations. (i) Periodic medical examinations shall be made available annually.

(ii) The scope of the medical examination shall be in conformance with the protocol established in paragraph (l)(2)(ii) of this section, except that the frequency of chest roentgenogram shall be conducted in accordance with Table 2, and the abbreviated standardized questionnaire contained in, Part 2 of Appendix D to this section shall be administered to the employee.

Table 2. -- Frequency of Chest Roentgenogram
Years since first exposure Age of emp
15 to 35 35+ to 40 45+
0 to 10 Every 5 years Every 5 years Every 5 years
10+ Every 5 years Every 2 years Every 1 year

(4) Termination of employment examinations. (i) The employer shall provide, or make available, a termination of employment medical examination for any employee who has been exposed to airborne concentrations of fibers of asbestos at or above the TWA and/or excursion limit.

(ii) The medical examination shall be in accordance with the requirements of the periodic examinations stipulated in paragraph (l)(3) of this section, and shall be given within 30 calendar days before or after the date of termination of employment.

(5) Recent examinations. No medical examination is required of any employee, if adequate records show that the employee has been examined in accordance with any of paragraphs ((l)(2) through (l)(4)) of this section within the past 1 year period. A pre- employment medical examination which was required as a condition of employment by the employer, may not be used by that employer to meet the requirements of this paragraph, unless the cost of such examination is borne by the employer.

(6) Information provided to the physician. The employer shall provide the following information to the examining physician:

(i) A copy of this standard and Appendices D and E. (ii) A description of the affected employee's duties as they relate to the employee's exposure.

(iii) The employee's representative exposure level or anticipated exposure level.

(iv) A description of any personal protective and respiratory equipment used or to be used.

(v) Information from previous medical examinations of the affected employee that is not otherwise available to the examining physician.

(7) Physician's written opinion. (i) The employer shall obtain a written signed opinion from the examining physician. This written opinion shall contain the results of the medical examination and shall include:

(A) The physician's opinion as to whether the employee has any detected medical conditions that would place the employee at an increased risk of material health impairment from exposure to asbestos;

(B) Any recommended limitations on the employee or upon the use of personal protective equipment such as clothing or respirators; and

(C) A statement that the employee has been informed by the physician of the results of the medical examination and of any medical conditions resulting from asbestos exposure that require further explanation or treatment.

(D) A statement that the employee has been informed by the physician of the increased risk of lung cancer attributable to the combined effect of smoking and asbestos exposure.

(ii) The employer shall instruct the physician not to reveal in the written opinion given to the employer specific findings or diagnoses unrelated to occupational exposure to asbestos.

(iii) The employer shall provide a copy of the physician's written opinion to the affected employee within 30 days from its receipt.

(m) Recordkeeping. -- (1) Exposure measurements. NOTE: The employer may utilize the services of competent organizations such as industry trade associations and employee associations to maintain the records required by this section. (i) The employer shall keep an accurate record of all measurements taken to monitor employee exposure to asbestos as prescribed in paragraph (d) of this section.

(ii) This record shall include at least the following information:

(A) The date of measurement;

(B) The operation involving exposure to asbestos which is being monitored;

(C) Sampling and analytical methods used and evidence of their accuracy;

(D) Number, duration, and results of samples taken;

(E) Type of respiratory protective devices worn, if any; and

(F) Name, social security number and exposure of the employees whose exposure are represented.

(iii) The employer shall maintain this record for at least thirty (30) years, in accordance with 29 CFR 1910.20.

(2) Objective data for exempted operations. (i) Where the processing, use, or handling of products made from or containing asbestos is exempted from other requirements of this section under paragraph (d)(2)(iii) of this section, the employer shall establish and maintain an accurate record of objective data reasonably relied upon in support of the exemption.

(ii) The record shall include at least the following:

(A) The product qualifying for exemption;

(B) The source of the objective data;

(C) The testing protocol, results of testing, and/or analysis of the material for the release of asbestos;

(D) A description of the operation exempted and how the data support the exemption; and

(E) Other data relevant to the operations, materials, processing, or employee exposures covered by the exemption.

(iii) The employer shall maintain this record for the duration of the employer's reliance upon such objective data.

(3) Medical surveillance. (i) The employer shall establish and maintain an accurate record for each employee subject to medical surveillance by paragraph (l)(1)(i) of this section, in accordance with 29 CFR 1910.20.

(ii) The record shall include at least the following information:

(A) The name and social security number of the employee;

(B) Physician's written opinions;

(C) Any employee medical complaints related to exposure to asbestos; and

(D) A copy of the information provided to the physician as required by paragraph (l)(6) of this section.

(iii) The employer shall ensure that this record is maintained for the duration of employment plus thirty (30) years, in accordance with 29 CFR 1910.20.

(4) Training. The employer shall maintain all employee training records for one (1) year beyond the last date of employment of that employee.

(5) Availability. (i) The employer, upon written request, shall make all records required to be maintained by this section available to the Assistant Secretary and the Director for examination and copying.

(ii) The employer, upon request shall make any exposure records required by paragraph (m)(1) of this section available for examination and copying to affected employees, former employees, designated representatives and the Assistant Secretary, in accordance with 29 CFR 1910.20(a) through (e) and (g) through (i).

(iii) The employer, upon request, shall make employee medical records required by paragraph (m)(2) of this section available for examination and copying to the subject employee, to anyone having the specific written consent of the subject employee, and the Assistant Secretary, in accordance with 29 CFR 1910.20.

(6) Transfer of records. (i) The employer shall comply with the requirements concerning transfer of records set forth in 29 CFR 1910.20(h).

(ii) Whenever the employer ceases to do business and there is no successor employer to receive and retain the records for the prescribed period, the employer shall notify the Director at least 90 days prior to disposal of records and, upon request, transmit them to the Director.

(n) Observation of monitoring -- (1) Employee observation. The employer shall provide affected employees or their designated representatives an opportunity to observe any monitoring of employee exposure to asbestos conducted in accordance with paragraph (d) of this section.

(2) Observation procedures. When observation of the monitoring of employee exposure to asbestos requires entry into an area where the use of protective clothing or equipment is required, the observer shall be provided with and be required to use such clothing and equipment and shall comply with all other applicable safety and health procedures.

(o) Dates -- (1) Effective date. This standard shall become effective October 11, 1994.

(2) The provisions of 29 CFR 1910.1001 remain in effect until the start-up dates of the equivalent provisions of this standard.

(3) Start-up dates. All obligations of this standard commence on the effective date except as follows:

(i) Exposure monitoring. Initial monitoring required by paragraph (d)(2) of this section shall be completed as soon as possible but no later than January 9, 1995.

(ii) Regulated areas. Regulated areas required to be established by paragraph (e) of this section as a result of initial monitoring shall be set up as soon as possible after the results of that monitoring are known and not later than February 8, 1995.

(iii) Respiratory protection. Respiratory protection required by paragraph (g) of this section shall be provided as soon as possible but no later than January 9, 1995.

(iv) Hygiene and lunchroom facilities. Construction plans for change rooms, showers, lavatories, and lunchroom facilities shall be completed as soon as possible but no later than July 10, 1995.

(v) Employee information and training. Employee information and training shall be provided as soon as possible but not later than April 10, 1995.

(vi) Medical surveillance. Medical surveillance not previously required by paragraph (l) of this section shall be provided as soon as possible but no later than January 9, 1995.

(vii) Compliance program. Written compliance programs required by paragraph (f)(2) of this section shall be completed and available for inspection and copying as soon as possible but no later than February 8, 1995.

(viii) Methods of compliance. The engineering and work practice controls as required by paragraph (f)(1) shall be implemented as soon as possible but no later than April 10, 1995.

(p) Appendices. (1) Appendices A, C, D, E, and F to this section are incorporated as part of this section and the contents of these Appendices are mandatory.

(2) Appendices B, F, G, H, I, and J to this section are informational and are not intended to create any additional obligations not otherwise imposed or to detract from any existing obligations.

(Approved by the Office of Management and Budget under control number 1218-0133)

Appendix A to 1910.1001 [Amended]

4. Appendix A to Sec. 1910.1001 is amended by the revising the second sentence of the introductory paragraph to read as follows:

* * * The sampling and analytical methods described below represent the elements of the available monitoring methods (such as Appendix B of their regulation, the most current version of the OSHA method ID-160, or the most current version of the NIOSH Method 7400). * * * * * * * *

5. Paragraph 2. of the section of Appendix A to Sec. 1910.1001 entitled Sampling and Analytical Procedure is amended by adding the following sentence to the end:

* * * * *

2. * * * Do not reuse or reload cassettes for asbestos sample collection.

* * * * *

6. Paragraph 11 of the section of Appendix A to Sec. 1910.1001 entitled Sampling and Analytical Procedure is revised to read as follows:

* * * * *

11. Each set of samples taken will include 10% field blanks or a minimum of 2 field blanks. These blanks must come from the same lot as the filters used for sample collection. The field blank results shall be averaged and subtracted from the analytical results before reporting. A set consists of any sample or group of samples for which an evaluation for this standard must be made. Any samples represented by a field blank having a fiber count in excess of the detection limit of the method being used shall be rejected.

* * * * *

7. Paragraph 2 of the section of Appendix A to Sec. 1910.1001 entitled Quality Control Procedures is amended by redesignating it as paragraph 2a and by adding paragraph 2b to read as follows:

* * * * *

2.b. All laboratories should also participate in a national sample testing scheme such as the Proficiency Analytical Testing Program (PAT), or the Asbestos Registry sponsored by the American Industrial Hygiene Association (AIHA).

* * * * *

8. Appendix B of 1910.1001 is revised to read as follows:

Appendix B to 1910.1001 -- Detailed Procedures for Asbestos Sampling and Analysis -- Non-mandatory

Matrix:
  • OSHA Permissible Exposure Limits:
  • Time Weighted Average
0.1 fiber/cc
  • Excursion Level (30 minutes)
1.0 fiber/cc
Collection Procedure:
  • A known volume of air is drawn through a 25-mm diameter cassette containing a mixed-cellulose ester filter. The cassette must be equipped with an electrically conductive 50-mm extension cowl. The sampling time and rate are chosen to give a fiber density of between 100 to 1,300 fibers/mm(2) on the filter
Recommended Sampling Rate 0.5 to 5.0 liters/minute (L/min)
Recommended Air Volumes:
  • Minimum
25 L
  • Maximum
2,400 L

Analytical Procedure: A portion of the sample filter is cleared and prepared for asbestos fiber counting by Phase Contrast Microscopy (PCM) at 400X.

Commercial manufacturers and products mentioned in this method are for descriptive use only and do not constitute endorsements by USDOL-OSHA. Similar products from other sources can be substituted.

1. Introduction

This method describes the collection of airborne asbestos fibers using calibrated sampling pumps with mixed-cellulose ester (MCE) filters and analysis by phase contrast microscopy (PCM). Some terms used are unique to this method and are defined below:

Asbestos: A term for naturally occurring fibrous minerals. Asbestos includes chrysotile, crocidolite, amosite (cummingtonite- grunerite asbestos), tremolite asbestos, actinolite asbestos, anthophyllite asbestos, and any of these minerals that have been chemically treated and/or altered. The precise chemical formulation of each species will vary with the location from which it was mined. Nominal compositions are listed:

Chrysotile Mg(3)Si(2)O(5)(OH)(4)
Crocidolite Na(2)Fe(3)(2)+Fe2(3)+Si(8)O(2)2(OH)(2)
Amosite (Mg,Fe)(7)Si(8)O(2)2(OH)(2)
Tremolite-actinolite Ca(2)(Mg,Fe)(5)Si(8)O(2)2(OH)(2)
Anthophyllite (Mg,Fe)(7)Si(8)O(2)2(OH)(2)

Asbestos Fiber: A fiber of asbestos which meets the criteria specified below for a fiber.

Aspect Ratio: The ratio of the length of a fiber to it's diameter (e.g. 3:1, 5:1 aspect ratios).

Cleavage Fragments: Mineral particles formed by comminution of minerals, especially those characterized by parallel sides and a moderate aspect ratio (usually less than 20:1).

Detection Limit: The number of fibers necessary to be 95% certain that the result is greater than zero.

Differential Counting: The term applied to the practice of excluding certain kinds of fibers from the fiber count because they do not appear to be asbestos.

Fiber: A particle that is 5 um or longer, with a length- to-width ratio of 3 to 1 or longer.

Field: The area within the graticule circle that is superimposed on the microscope image.

Set: The samples which are taken, submitted to the laboratory, analyzed, and for which, interim or final result reports are generated.

Tremolite, Anthophyllite, and Actinolite: The non-asbestos form of these minerals which meet the definition of a fiber. It includes any of these minerals that have been chemically treated and/or altered.

Walton-Beckett Graticule: An eyepiece graticule specifically designed for asbestos fiber counting. It consists of a circle with a projected diameter of 100 # 2 um (area of about 0.00785 mm(2)) with a crosshair having tic-marks at 3-um intervals in one direction and 5-um in the orthogonal direction. There are marks around the periphery of the circle to demonstrate the proper sizes and shapes of fibers. This design is reproduced in Figure 2. The disk is placed in one of the microscope eyepieces so that the design is superimposed on the field of view.

1.1. History

Early surveys to determine asbestos exposures were conducted using impinger counts of total dust with the counts expressed as million particles per cubic foot. The British Asbestos Research Council recommended filter membrane counting in 1969. In July 1969, the Bureau of Occupational Safety and Health published a filter membrane method for counting asbestos fibers in the United States. This method was refined by NIOSH and published as P&CAM 239. On May 29, 1971, OSHA specified filter membrane sampling with phase contrast counting for evaluation of asbestos exposures at work sites in the United States. The use of this technique was again required by OSHA in 1986. Phase contrast microscopy has continued to be the method of choice for the measurement of occupational exposure to asbestos.

1.2. Principle

Air is drawn through a MCE filter to capture airborne asbestos fibers. A wedge shaped portion of the filter is removed, placed on a glass microscope slide and made transparent. A measured area (field) is viewed by PCM. All the fibers meeting a defined criteria for asbestos are counted and considered a measure of the airborne asbestos concentration.

1.3. Advantages and Disadvantages

There are four main advantages of PCM over other methods:

(1) The technique is specific for fibers. Phase contrast is a fiber counting technique which excludes non-fibrous particles from the analysis.

(2) The technique is inexpensive and does not require specialized knowledge to carry out the analysis for total fiber counts.

(3) The analysis is quick and can be performed on-site for rapid determination of air concentrations of asbestos fibers.

(4) The technique has continuity with historical epidemiological studies so that estimates of expected disease can be inferred from long-term determinations of asbestos exposures.

The main disadvantage of PCM is that it does not positively identify asbestos fibers. Other fibers which are not asbestos may be included in the count unless differential counting is performed. This requires a great deal of experience to adequately differentiate asbestos from non-asbestos fibers. Positive identification of asbestos must be performed by polarized light or electron microscopy techniques. A further disadvantage of PCM is that the smallest visible fibers are about 0.2 um in diameter while the finest asbestos fibers may be as small as 0.02 um in diameter. For some exposures, substantially more fibers may be present than are actually counted.

1.4. Workplace Exposure

Asbestos is used by the construction industry in such products as shingles, floor tiles, asbestos cement, roofing felts, insulation and acoustical products. Non-construction uses include brakes, clutch facings, paper, paints, plastics, and fabrics. One of the most significant exposures in the workplace is the removal and encapsulation of asbestos in schools, public buildings, and homes. Many workers have the potential to be exposed to asbestos during these operations.

About 95% of the asbestos in commercial use in the United States is chrysotile. Crocidolite and amosite make up most of the remainder. Anthophyllite and tremolite or actinolite are likely to be encountered as contaminants in various industrial products.

1.5. Physical Properties

Asbestos fiber possesses a high tensile strength along its axis, is chemically inert, non-combustible, and heat resistant. It has a high electrical resistance and good sound absorbing properties. It can be weaved into cables, fabrics or other textiles, and also matted into asbestos papers, felts, or mats.

2. Range and Detection Limit

2.1. The ideal counting range on the filter is 100 to 1,300 fibers/mm(2). With a Walton-Beckett graticule this range is equivalent to 0.8 to 10 fibers/field. Using NIOSH counting statistics, a count of 0.8 fibers/field would give an approximate coefficient of variation (CV) of 0.13.

2.2. The detection limit for this method is 4.0 fibers per 100 fields or 5.5 fibers/mm(2). This was determined using an equation to estimate the maximum CV possible at a specific concentration (95% confidence) and a Lower Control Limit of zero. The CV value was then used to determine a corresponding concentration from historical CV vs fiber relationships. As an example:

Lower Control Limit (95% Confidence) = AC - 1.645(CV)(AC)

Where:

AC = Estimate of the airborne fiber concentration (fibers/cc)

Setting the Lower Control Limit = 0 and solving for CV:

0 = AC - 1.645(CV)(AC) CV = 0.61

This value was compared with CV vs. count curves. The count at which CV = 0.61 for Leidel-Busch counting statistics or for an OSHA Salt Lake Technical Center (OSHA-SLTC) CV curve (see Appendix A for further information) was 4.4 fibers or 3.9 fibers per 100 fields, respectively. Although a lower detection limit of 4 fibers per 100 fields is supported by the OSHA-SLTC data, both data sets support the 4.5 fibers per 100 fields value.

3. Method Performance -- Precision and Accuracy

Precision is dependent upon the total number of fibers counted and the uniformity of the fiber distribution on the filter. A general rule is to count at least 20 and not more than 100 fields. The count is discontinued when 100 fibers are counted, provided that 20 fields have already been counted. Counting more than 100 fibers results in only a small gain in precision. As the total count drops below 10 fibers, an accelerated loss of precision is noted.

At this time, there is no known method to determine the absolute accuracy of the asbestos analysis. Results of samples prepared through the Proficiency Analytical Testing (PAT) Program and analyzed by the OSHA-SLTC showed no significant bias when compared to PAT reference values. The PAT samples were analyzed from 1987 to 1989 (N=36) and the concentration range was from 120 to 1,300 fibers/mm(2).

4. Interferences

Fibrous substances, if present, may interfere with asbestos analysis.

Some common fibers are:

Fiber glass anhydrite plant fibers. Perlite veins.

Gypsum............................. Some synthetic fibers.

Membrane structures................ Sponge spicules and diatoms.

Microorganisms..................... Wollastonite.

The use of electron microscopy or optical tests such as polarized light, and dispersion staining may be used to differentiate these materials from asbestos when necessary.

5. Sampling

5.1. Equipment

5.1.1. Sample assembly (The assembly is shown in Figure 3). Conductive filter holder consisting of a 25-mm diameter, 3-piece cassette having a 50-mm long electrically conductive extension cowl. Backup pad, 25-mm, cellulose. Membrane filter, mixed-cellulose ester (MCE), 25-mm, plain, white, 0.8- to 1.2-um pore size.

Notes: (a) Do not re-use cassettes. (b) Fully conductive cassettes are required to reduce fiber loss to the sides of the cassette due to electrostatic attraction. (c) Purchase filters which have been selected by the manufacturer for asbestos counting or analyze representative filters for fiber background before use. Discard the filter lot if more than 4 fibers/100 fields are found. (d) To decrease the possibility of contamination, the sampling system (filter-backup pad-cassette) for asbestos is usually preassembled by the manufacturer.

5.1.2. Gel bands for sealing cassettes.

5.1.3. Sampling pump. Each pump must be a battery operated, self-contained unit small enough to be placed on the monitored employee and not interfere with the work being performed. The pump must be capable of sampling at 2.5 liters per minute (L/min) for the required sampling time.

5.1.4. Flexible tubing, 6-mm bore.

5.1.5. Pump calibration. Stopwatch and bubble tube/burette or electronic meter.

5.2. Sampling Procedure

5.2.1. Seal the point where the base and cowl of each cassette meet (see Figure 3) with a gel band or tape.

5.2.2. Charge the pumps completely before beginning.

5.2.3. Connect each pump to a calibration cassette with an appropriate length of 6-mm bore plastic tubing. Do not use luer connectors -- the type of cassette specified above has built-in adapters.

5.2.4. Select an appropriate flow rate for the situation being monitored. The sampling flow rate must be between 0.5 and 5.0 L/min for personal sampling and is commonly set between 1 and 2 L/min. Always choose a flow rate that will not produce overloaded filters.

5.2.5. Calibrate each sampling pump before and after sampling with a calibration cassette in-line (Note: This calibration cassette should be from the same lot of cassettes used for sampling). Use a primary standard (e.g. bubble burette) to calibrate each pump. If possible, calibrate at the sampling site.

Note: If sampling site calibration is not possible, environmental influences may affect the flow rate. The extent is dependent on the type of pump used. Consult with the pump manufacturer to determine dependence on environmental influences. If the pump is affected by temperature and pressure changes, use the formula in Appendix B to calculate the actual flow rate.

5.2.6. Connect each pump to the base of each sampling cassette with flexible tubing. Remove the end cap of each cassette and take each air sample open face. Assure that each sample cassette is held open side down in the employee's breathing zone during sampling. The distance from the nose/mouth of the employee to the cassette should be about 10 cm. Secure the cassette on the collar or lapel of the employee using spring clips or other similar devices.

5.2.7. A suggested minimum air volume when sampling to determine TWA compliance is 25 L. For Excursion Limit (30 min sampling time) evaluations, a minimum air volume of 48 L is recommended.

5.2.8. The most significant problem when sampling for asbestos is overloading the filter with non-asbestos dust. Suggested maximum air sample volumes for specific environments are:

Environment Air vol. (L)
Asbestos removal operations (visible dust) 100
Asbestos removal operations (little dust) 240
Office environments 400 to 2,400

Caution: Do not overload the filter with dust. High levels of non-fibrous dust particles may obscure fibers on the filter and lower the count or make counting impossible. If more than about 25 to 30% of the field area is obscured with dust, the result may be biased low. Smaller air volumes may be necessary when there is excessive non-asbestos dust in the air.

While sampling, observe the filter with a small flashlight. If there is a visible layer of dust on the filter, stop sampling, remove and seal the cassette, and replace with a new sampling assembly. The total dust loading should not exceed 1 mg.

5.2.9. Blank samples are used to determine if any contamination has occurred during sample handling. Prepare two blanks for the first 1 to 20 samples. For sets containing greater than 20 samples, prepare blanks as 10% of the samples. Handle blank samples in the same manner as air samples with one exception: Do not draw any air through the blank samples. Open the blank cassette in the place where the sample cassettes are mounted on the employee. Hold it open for about 30 seconds. Close and seal the cassette appropriately. Store blanks for shipment with the sample cassettes.

5.2.10. Immediately after sampling, close and seal each cassette with the base and plastic plugs. Do not touch or puncture the filter membrane as this will invalidate the analysis.

5.2.11. Attach a seal (OSHA-21 or equivalent) around each cassette in such a way as to secure the end cap plug and base plug. Tape the ends of the seal together since the seal is not long enough to be wrapped end-to-end. Also wrap tape around the cassette at each joint to keep the seal secure.

5.3. Sample Shipment

5.3.1. Send the samples to the laboratory with paperwork requesting asbestos analysis. List any known fibrous interferences present during sampling on the paperwork. Also, note the workplace operation(s) sampled.

5.3.2. Secure and handle the samples in such that they will not rattle during shipment nor be exposed to static electricity. Do not ship samples in expanded polystyrene peanuts, vermiculite, paper shreds, or excelsior. Tape sample cassettes to sheet bubbles and place in a container that will cushion the samples without rattling.

5.3.3. To avoid the possibility of sample contamination, always ship bulk samples in separate mailing containers.

6. Analysis

6.1. Safety Precautions

6.1.1. Acetone is extremely flammable and precautions must be taken not to ignite it. Avoid using large containers or quantities of acetone. Transfer the solvent in a ventilated laboratory hood. Do not use acetone near any open flame. For generation of acetone vapor, use a spark free heat source.

6.1.2. Any asbestos spills should be cleaned up immediately to prevent dispersal of fibers. Prudence should be exercised to avoid contamination of laboratory facilities or exposure of personnel to asbestos. Asbestos spills should be cleaned up with wet methods and/ or a High Efficiency Particulate-Air (HEPA) filtered vacuum.

Caution: Do not use a vacuum without a HEPA filter -- It will disperse fine asbestos fibers in the air.

6.2. Equipment

6.2.1. Phase contrast microscope with binocular or trinocular head.

6.2.2. Widefield or Huygenian 10X eyepieces (Note: The eyepiece containing the graticule must be a focusing eyepiece. Use a 40X phase objective with a numerical aperture of 0.65 to 0.75).

6.2.3. Kohler illumination (if possible) with green or blue filter.

6.2.4. Walton-Beckett Graticule, type G-22 with 100 plus or minus 2 um projected diameter.

6.2.5. Mechanical stage. A rotating mechanical stage is convenient for use with polarized light. 6.2.6. Phase telescope. 6.2.7. Stage micrometer with 0.01-mm subdivisions. 6.2.8. Phase-shift test slide, mark II (Available from PTR optics Ltd., and also McCrone).

6.2.9. Precleaned glass slides, 25 mm X 75 mm. One end can be frosted for convenience in writing sample numbers, etc., or paste-on labels can be used.

6.2.10. Cover glass #1 1/2.

6.2.11. Scalpel (#10, curved blade).

6.2.12. Fine tipped forceps.

6.2.13. Aluminum block for clearing filter (see Appendix D and Figure 4).

6.2.14. Automatic adjustable pipette, 100- to 500-uL.

6.2.15. Micropipette, 5 uL.

6.3. Reagents

6.3.1. Acetone (HPLC grade).

6.3.2. Triacetin (glycerol triacetate).

6.3.3. Lacquer or nail polish.

6.4. Standard Preparation

A way to prepare standard asbestos samples of known concentration has not been developed. It is possible to prepare replicate samples of nearly equal concentration. This has been performed through the PAT program. These asbestos samples are distributed by the AIHA to participating laboratories.

Since only about one-fourth of a 25-mm sample membrane is required for an asbestos count, any PAT sample can serve as a "standard" for replicate counting.

6.5. Sample Mounting

Note: See Safety Precautions in Section 6.1. before proceeding. The objective is to produce samples with a smooth (non-grainy) background in a medium with a refractive index of approximately 1.46. The technique below collapses the filter for easier focusing and produces permanent mounts which are useful for quality control and interlaboratory comparison.

An aluminum block or similar device is required for sample preparation. A drawing is shown in Figure 4.

6.5.1. Heat the aluminum block to about 70 deg. C. The hot block should not be used on any surface that can be damaged by either the heat or from exposure to acetone.

6.5.2. Ensure that the glass slides and cover glasses are free of dust and fibers.

6.5.3. Remove the top plug to prevent a vacuum when the cassette is opened. Clean the outside of the cassette if necessary. Cut the seal and/or tape on the cassette with a razor blade. Very carefully separate the base from the extension cowl, leaving the filter and backup pad in the base.

6.5.4. With a rocking motion cut a triangular wedge from the filter using the scalpel. This wedge should be one-sixth to one- fourth of the filter. Grasp the filter wedge with the forceps on the perimeter of the filter which was clamped between the cassette pieces. DO NOT TOUCH the filter with your finger. Place the filter on the glass slide sample side up. Static electricity will usually keep the filter on the slide until it is cleared.

6.5.5. Place the tip of the micropipette containing about 200 uL acetone into the aluminum block. Insert the glass slide into the receiving slot in the aluminum block. Inject the acetone into the block with slow, steady pressure on the plunger while holding the pipette firmly in place. Wait 3 to 5 seconds for the filter to clear, then remove the pipette and slide from the aluminum block.

6.5.6. Immediately (less than 30 seconds) place 2.5 to 3.5 uL of triacetin on the filter (Note: Waiting longer than 30 seconds will result in increased index of refraction and decreased contrast between the fibers and the preparation. This may also lead to separation of the cover slip from the slide).

6.5.7. Lower a cover slip gently onto the filter at a slight angle to reduce the possibility of forming air bubbles. If more than 30 seconds have elapsed between acetone exposure and triacetin application, glue the edges of the cover slip to the slide with lacquer or nail polish.

6.5.8. If clearing is slow, warm the slide for 15 min on a hot plate having a surface temperature of about 50 deg.C to hasten clearing. The top of the hot block can be used if the slide is not heated too long.

6.5.9. Counting may proceed immediately after clearing and mounting are completed.

6.6. Sample Analysis

Completely align the microscope according to the manufacturer's instructions. Then, align the microscope using the following general alignment routine at the beginning of every counting session and more often if necessary.

6.6.1. Alignment

(1) Clean all optical surfaces. Even a small amount of dirt can significantly degrade the image.

(2) Rough focus the objective on a sample.

(3) Close down the field iris so that it is visible in the field of view. Focus the image of the iris with the condenser focus. Center the image of the iris in the field of view.

(4) Install the phase telescope and focus on the phase rings. Critically center the rings. Misalignment of the rings results in astigmatism which will degrade the image.

(5) Place the phase-shift test slide on the microscope stage and focus on the lines. The analyst must see line set 3 and should see at least parts of 4 and 5 but, not see line set 6 or 6. A microscope/microscopist combination which does not pass this test may not be used.

6.6.2. Counting Fibers

(1) Place the prepared sample slide on the mechanical stage of the microscope. Position the center of the wedge under the objective lens and focus upon the sample.

(2) Start counting from one end of the wedge and progress along a radial line to the other end (count in either direction from perimeter to wedge tip). Select fields randomly, without looking into the eyepieces, by slightly advancing the slide in one direction with the mechanical stage control.

(3) Continually scan over a range of focal planes (generally the upper 10 to 15 um of the filter surface) with the fine focus control during each field count. Spend at least 5 to 15 seconds per field.

(4) Most samples will contain asbestos fibers with fiber diameters less than 1 um. Look carefully for faint fiber images. The small diameter fibers will be very hard to see. However, they are an important contribution to the total count.

(5) Count only fibers equal to or longer than 5 um. Measure the length of curved fibers along the curve.

(6) Count fibers which have a length to width ratio of 3:1 or greater.

(7) Count all the fibers in at least 20 fields. Continue counting until either 100 fibers are counted or 100 fields have been viewed; whichever occurs first. Count all the fibers in the final field.

(8) Fibers lying entirely within the boundary of the Walton- Beckett graticule field shall receive a count of 1. Fibers crossing the boundary once, having one end within the circle shall receive a count of 1/2. Do not count any fiber that crosses the graticule boundary more than once. Reject and do not count any other fibers even though they may be visible outside the graticule area. If a fiber touches the circle, it is considered to cross the line.

(9) Count bundles of fibers as one fiber unless individual fibers can be clearly identified and each individual fiber is clearly not connected to another counted fiber. See Figure 2 for counting conventions.

(10) Record the number of fibers in each field in a consistent way such that filter non-uniformity can be assessed.

(11) Regularly check phase ring alignment.

(12) When an agglomerate (mass of material) covers more than 25% of the field of view, reject the field and select another. Do not include it in the number of fields counted.

(13) Perform a "blind recount" of 1 in every 10 filter wedges (slides). Re-label the slides using a person other than the original counter.

6.7. Fiber Identification

As previously mentioned in Section 1.3., PCM does not provide positive confirmation of asbestos fibers. Alternate differential counting techniques should be used if discrimination is desirable. Differential counting may include primary discrimination based on morphology, polarized light analysis of fibers, or modification of PCM data by Scanning Electron or Transmission Electron Microscopy.

A great deal of experience is required to routinely and correctly perform differential counting. It is discouraged unless it is legally necessary. Then, only if a fiber is obviously not asbestos should it be excluded from the count. Further discussion of this technique can be found in reference 8.10.

If there is a question whether a fiber is asbestos or not, follow the rule:

"WHEN IN DOUBT, COUNT."

6.8. Analytical Recommendations -- Quality Control System

6.8.1. All individuals performing asbestos analysis must have taken the NIOSH course for sampling and evaluating airborne asbestos or an equivalent course.

6.8.2. Each laboratory engaged in asbestos counting shall set up a slide trading arrangement with at least two other laboratories in order to compare performance and eliminate inbreeding of error. The slide exchange occurs at least semiannually. The round robin results shall be posted where all analysts can view individual analyst's results.

6.8.3. Each laboratory engaged in asbestos counting shall participate in the Proficiency Analytical Testing Program, the Asbestos Analyst Registry or equivalent.

6.8.4. Each analyst shall select and count prepared slides from a "slide bank". These are quality assurance counts. The slide bank shall be prepared using uniformly distributed samples taken from the workload. Fiber densities should cover the entire range routinely analyzed by the laboratory. These slides are counted blind by all counters to establish an original standard deviation. This historical distribution is compared with the quality assurance counts. A counter must have 95% of all quality control samples counted within three standard deviations of the historical mean. This count is then integrated into a new historical mean and standard deviation for the slide.

The analyses done by the counters to establish the slide bank may be used for an interim quality control program if the data are treated in a proper statistical fashion.

7. CALCULATIONS

7.1. Calculate the estimated airborne asbestos fiber concentration on the filter sample using the following formula: Where:

AC = Airborne fiber concentration

(For Equation, see paper copy)
FB = Total number of fibers greater than 5 um counted
FL = Total number of fields counted on the filter
BFB = Total number of fibers greater than 5 um counted in the blank
BFL = Total number of fields counted on the blank
ECA = Effective collecting area of filter (385 mm(2) nominal for a 25-mm filter.)
FR = Pump flow rate (L/min)
MFA = Microscope count field area (mm(2)). This is 0.00785 mm(2) for a Walton-Beckett Graticule
T = Sample collection time (min)
1,000 = Conversion of L to cc

Note: The collection area of a filter is seldom equal to 385 mm(2). It is appropriate for laboratories to routinely monitor the exact diameter using an inside micrometer. The collection area is calculated according to the formula:

Area = Pie(d/2)(2)

7.2. Short-cut Calculation

Since a given analyst always has the same interpupillary distance, the number of fields per filter for a particular analyst will remain constant for a given size filter. The field size for that analyst is constant (i.e. the analyst is using an assigned microscope and is not changing the reticle).

For example, if the exposed area of the filter is always 385 mm(2) and the size of the field is always 0.00785 mm(2), the number of fields per filter will always be 49,000. In addition it is necessary to convert liters of air to cc. These three constants can then be combined such that ECA/(1,000 X MFA)=49. The previous equation simplifies to:

(For Equation, see paper copy)

7.3. Recount Calculations

As mentioned in step 13 of Section 6.6.2., a "blind recount" of 10% of the slides is performed. In all cases, differences will be observed between the first and second counts of the same filter wedge. Most of these differences will be due to chance alone, that is, due to the random variability (precision) of the count method. Statistical recount criteria enables one to decide whether observed differences can be explained due to chance alone or are probably due to systematic differences between analysts, microscopes, or other biasing factors.

The following recount criterion is for a pair of counts that estimate AC in fibers/cc. The criterion is given at the type-I error level. That is, there is 5% maximum risk that we will reject a pair of counts for the reason that one might be biased, when the large observed difference is really due to chance.

Reject a pair of counts if:

(For Equation, see paper copy)

Where:
AC1 = lower estimated airborne fiber concentration
AC2 = higher estimated airborne fiber concentration
AC(avg) = average of the two concentration estimates
CV(FB) = CV for the average of the two concentration estimates

If a pair of counts are rejected by this criterion then, recount the rest of the filters in the submitted set. Apply the test and reject any other pairs failing the test. Rejection shall include a memo to the industrial hygienist stating that the sample failed a statistical test for homogeneity and the true air concentration may be significantly different than the reported value.

7.4. Reporting Results

Report results to the industrial hygienist as fibers/cc. Use two significant figures. If multiple analyses are performed on a sample, an average of the results is to be reported unless any of the results can be rejected for cause.

8. References

8.1. Dreesen, W.C., et al, U.S. Public Health Service: A Study of Asbestosis in the Asbestos Textile Industry, (Public Health Bulletin No. 241), US Treasury Dept., Washington, DC, 1938.

8.2. Asbestos Research Council: The Measurement of Airborne Asbestos Dust by the Membrane Filter Method (Technical Note), Asbestos Research Council, Rockdale, Lancashire, Great Britain, 1969.

8.3. Bayer, S.G., Zumwalde, R.D., Brown, T.A., Equipment and Procedure for Mounting Millipore Filters and Counting Asbestos Fibers by Phase Contrast Microscopy, Bureau of Occupational Health, U.S. Dept. of Health, Education and Welfare, Cincinnati, OH, 1969.

8.4. NIOSH Manual of Analytical Methods, 2nd ed., Vol. 1 (DHEW/ NIOSH Pub. No. 77-157-A). National Institute for Occupational Safety and Health, Cincinnati, OH, 1977. pp. 239-1-239-21.

8.5. Asbestos, Code of Federal Regulations 29 CFR 1910.1001. 1971.

8.6. Occupational Exposure to Asbestos, Tremolite, Anthophyllite, and Actinolite. Final Rule, Federal Register 51:119 (20 June 1986). pp.22612-22790.

8.7. Asbestos, Tremolite, Anthophyllite, and Actinolite, Code of Federal Regulations 1910.1001. 1988. pp 711-752.

8.8. Criteria for a Recommended Standard -- Occupational Exposure to Asbestos (DHEW/NIOSH Pub. No. HSM 72-10267), National Institute for Occupational Safety and Health NIOSH, Cincinnati,OH, 1972. pp. III-1-III-24.

8.9. Leidel, N.A., Bayer,S.G., Zumwalde, R.D.,Busch, K.A., USPHS/NIOSH Membrane Filter Method for Evaluating Airborne Asbestos Fibers (DHEW/NIOSH Pub. No. 79-127). National Institute for Occupational Safety and Health, Cincinnati, OH, 1979.

8.10. Dixon, W.C., Applications of Optical Microscopy in Analysis of Asbestos and Quartz, Analytical Techniques in Occupational Health Chemistry, edited by D.D. Dollberg and A.W. Verstuyft. Wash. D.C.: American Chemical Society, (ACS Symposium Series 120) 1980. pp. 13-41.

Quality Control

The OSHA asbestos regulations require each laboratory to establish a quality control program. The following is presented as an example of how the OSHA-SLTC constructed its internal CV curve as part of meeting this requirement. Data for the CV curve shown below is from 395 samples collected during OSHA compliance inspections and analyzed from October 1980 through April 1986.

Each sample was counted by 2 to 5 different counters independently of one another. The standard deviation and the CV statistic was calculated for each sample. This data was then plotted on a graph of CV vs. fibers/mm(2). A least squares regression was performed using the following equation:

CV = antilog1(10)[A(log(10)(x))(2) + B(log(10)(x)) + C]

where:

x = the number of fibers/mm(2) Application of least squares gave:

A = 0.182205 B = -0.973343 C = 0.327499

Using these values, the equation becomes:

 

 

CV = antilog(10)[0.182205(log(10)(x))(2) - 0.973343(log(10)(x)) + 0.327499]

Sampling Pump Flow Rate Corrections

This correction is used if a difference greater than 5% in ambient temperature and/or pressure is noted between calibration and sampling sites and the pump does not compensate for the differences.

(For Equation, see paper copy)

Where:
Q(act) = actual flow rate
Q(cal) = calibrated flow rate (if a rotameter was used, the rotameter value)
P(cal) = uncorrected air pressure at calibration
P(act) = uncorrected air pressure at sampling site
T(act) = temperature at sampling site (K)
T(cal) = temperature at calibration (K)

Walton-Beckett Graticule

When ordering the Graticule for asbestos counting, specify the exact disc diameter needed to fit the ocular of the microscope and the diameter (mm) of the circular counting area. Instructions for measuring the dimensions necessary are listed:

(1) Insert any available graticule into the focusing eyepiece and focus so that the graticule lines are sharp and clear.

(2) Align the microscope.

(3) Place a stage micrometer on the microscope object stage and focus the microscope on the graduated lines.

(4) Measure the magnified grid length, PL (um), using the stage micrometer.

(5) Remove the graticule from the microscope and measure its actual grid length, AL (mm). This can be accomplished by using a mechanical stage fitted with verniers, or a jeweler's loupe with a direct reading scale.

(6) Let D=100 um. Calculate the circle diameter, d(c)(mm), for the Walton-Beckett graticule and specify the diameter when making a purchase:

d(c) = AL x D
-- -- -- -- -
PL

Example: If PL=108 um, AL=2.93 mm and D=100 um, then,

d(c) = 2.93 x 100
-- -- -- -- -- -- -
108
= 2.71mm

(7) Each eyepiece-objective-reticle combination on the microscope must be calibrated. Should any of the three be changed (by zoom adjustment, disassembly, replacement, etc.), the combination must be recalibrated. Calibration may change if interpupillary distance is changed. Measure the field diameter, D (acceptable range: 100 plus or minus 2 um) with a stage micrometer upon receipt of the graticule from the manufacturer. Determine the field area (mm(2)).

Field Area = pie(D/2)2 If D = 100 - um = 0.1 mm, then Field Area = pie(0.1 mm/2)(2) = 0.00785 mm(2)

The Graticule is available from: Graticules Ltd., Morley Road, Tonbridge TN9 IRN, Kent, England (Telephone 011-44-732-359061). Also available from PTR Optics Ltd., 145 Newton Street, Waltham, MA 02154 [telephone (617) 891-6000] or McCrone Accessories and Components, 2506 S. Michigan Ave., Chicago, IL 60616 [phone (312)-842-7100]. The graticule is custom made for each microscope.

Counts for the Fibers in the Figure
Structure
No
Count Explanation
1 to 6 1 Single fibers all contained within the circle
7 1/2 Fiber crosses circle once
8 0 Fiber too short
9 2 Two crossing fibers
10 0 Fiber outside graticule
11 0 Fiber crosses graticule twice
12 1/2 Although split, fiber only crosses once

(For Figure 1, Walton-Beckett Graticule with some explanatory fibers. see paper copy)

9. Appendix D to Sec. 1910.1001 is amended by revising the first sentence to read as follows:

Appendix D to 1910.1001 -- Medical Questionnaires; Mandatory

This mandatory appendix contains the medical questionnaires that must be administered to all employees who are exposed to asbestos above the permissible exposure limit, and who will therefore be included in their employer's medical surveillance program. * * * * * * * *

10. Appendix F to Sec. 1910.1001 is revised to read as follows:

Appendix F to Sec. 1910.1001 -- Work Practices and Engineering Controls for Automotive Brake and Clutch Inspection, Disassembly, Repair and Assembly -- Mandatory

This mandatory appendix specifies engineering controls and work practices that must be implemented by the employer during automotive brake and clutch inspection, disassembly, repair, and assembly operations. Proper use of these engineering controls and work practices will reduce employees' asbestos exposure below the permissible exposure level during clutch and brake inspection, disassembly, repair, and assembly operations. The employer shall institute engineering controls and work practices using either the method set forth in paragraph [A] or paragraph [B] of this appendix, or any other method which the employer can demonstrate to be equivalent in terms of reducing employee exposure to asbestos as defined and which meets the requirements described in paragraph [C] of this appendix, for those facilities in which no more than 5 pairs of brakes or 5 clutches are inspected, disassembled, reassembled and/or repaired per week, the method set forth in paragraph [D] of this appendix may be used:

[A] Negative Pressure Enclosure/HEPA Vacuum System Method

(1) The brake and clutch inspection, disassembly, repair, and assembly operations shall be enclosed to cover and contain the clutch or brake assembly and to prevent the release of asbestos fibers into the worker's breathing zone.

(2) The enclosure shall be sealed tightly and thoroughly inspected for leaks before work begins on brake and clutch inspection, disassembly, repair, and assembly.

(3) The enclosure shall be such that the worker can clearly see the operation and shall provide impermeable sleeves through which the worker can handle the brake and clutch inspection, disassembly, repair and assembly. The integrity of the sleeves and ports shall be examined before work begins.

(4) A HEPA-filtered vacuum shall be employed to maintain the enclosure under negative pressure throughout the operation. Compressed-air may be used to remove asbestos fibers or particles from the enclosure.

(5) The HEPA vacuum shall be used first to loosen the asbestos containing residue from the brake and clutch parts and then to evacuate the loosened asbestos containing material from the enclosure and capture the material in the vacuum filter.

(6) The vacuum's filter, when full, shall be first wetted with a fine mist of water, then removed and placed immediately in an impermeable container, labeled according to paragraph (j)(2)(ii) of this section and disposed of according to paragraph (k) of this section.

(7) Any spills or releases of asbestos containing waste material from inside of the enclosure or vacuum hose or vacuum filter shall be immediately cleaned up and disposed of according to paragraph (k) of the section.

[B] Low Pressure/Wet Cleaning Method

(1) A catch basin shall be placed under the brake assembly, positioned to avoid splashes and spills.

(2) The reservoir shall contain water containing an organic solvent or wetting agent. The flow of liquid shall be controlled such that the brake assembly is gently flooded to prevent the asbestos-containing brake dust from becoming airborne.

(3) The aqueous solution shall be allowed to flow between the brake drum and brake support before the drum is removed.

(4) After removing the brake drum, the wheel hub and back of the brake assembly shall be thoroughly wetted to suppress dust.

(5) The brake support plate, brake shoes and brake components used to attach the brake shoes shall be thoroughly washed before removing the old shoes.

(6) In systems using filters, the filters, when full, shall be first wetted with a fine mist of water, then removed and placed immediately in an impermeable container, labeled according to paragraph (j)(2)(ii) of this section and disposed of according to paragraph (k) of this section.

(7) Any spills of asbestos-containing aqueous solution or any asbestos-containing waste material shall be cleaned up immediately and disposed of according to paragraph (k) of this section.

(8) The use of dry brushing during low pressure/wet cleaning operations is prohibited.

[C] Equivalent Methods

An equivalent method is one which has sufficient written detail so that it can be reproduced and has been demonstrated that the exposures resulting from the equivalent method are equal to or less than the exposures which would result from the use of the method described in paragraph [A] of this appendix. For purposes of making this comparison, the employer shall assume that exposures resulting from the use of the method described in paragraph [A] of this appendix shall not exceed 0.004 f/cc, as measured by the OSHA reference method and as averaged over at least 18 personal samples.

[D] Wet Method.

(1) A spray bottle, hose nozzle, or other implement capable of delivering a fine mist of water or amended water or other delivery system capable of delivering water at low pressure, shall be used to first thoroughly wet the brake and clutch parts. Brake and clutch components shall then be wiped clean with a cloth.

(2) The cloth shall be placed in an impermeable container, labelled according to paragraph (j)(2)(ii) of the standard and then disposed of according to paragraph (k) of the standard, or the cloth shall be laundered in a way to prevent the release of asbestos fibers in excess of 0.1 fiber per cubic centimeter of air.

(3) Any spills of solvent or any asbestos containing waste material shall be cleaned up immediately according to paragraph (k) of the standard. (4) The use of dry brushing during the wet method operations is prohibited.

Appendix G to 1910.1001 [Amended]

11. Appendix G of Sec. 1910.1001 is amended by replacing the phrase "0.2 f/cc" with the phrase "0.1 f/cc" in paragraph I. D. entitled "Permissible exposure:"..

12. Appendix G of Sec. 1910.1001 is amended by replacing the phrase "0.2 f/cc" with the phrase "0.1 f/cc" in paragraph III.A. entitled "Respirators:".

13. Appendix G of Sec. 1910.1001 is amended by revising paragraph III. B. to read as follows:

III. * * * B. Protective clothing: You are required to wear protective clothing in work areas where asbestos fiber concentrations exceed to permissible exposure limit.

* * * * *

Appendix H to Sec. 1910.1001 [Amended]

14. Appendix H of Sec. 1910.1001 is amended by revising the first sentence of the second paragraph of section IV. entitled Surveillance and Preventive Considerations to read as follows:

* * * * *

The employer is required to institute a medical surveillance program for all employees who are or will be exposed to asbestos at or above the permissible exposure limit (0.1 fiber per cubic centimeter of air). * * * * * * * *

15. Appendix J to Sec. 1910.1001 is added to read as follows:

Appendix J to Sec. 1910.1001 -- Polarized Light Microscopy of Asbestos -- Non-Mandatory)

Method number: ID-191 Matrix: Bulk

Collection Procedure

Collect approximately 1 to 2 grams of each type of material and place into separate 20 mL scintillation vials.

Analytical Procedure

A portion of each separate phase is analyzed by gross examination, phase-polar examination, and central stop dispersion microscopy.

Commercial manufacturers and products mentioned in this method are for descriptive use only and do not constitute endorsements by USDOL-OSHA. Similar products from other sources may be substituted.

1. Introduction

This method describes the collection and analysis of asbestos bulk materials by light microscopy techniques including phase- polar illumination and central-stop dispersion microscopy. Some terms unique to asbestos analysis are defined below:

Amphibole: A family of minerals whose crystals are formed by long, thin units which have two thin ribbons of double chain silicate with a brucite ribbon in between. The shape of each unit is similar to an "I beam". Minerals important in asbestos analysis include cummingtonite-grunerite, crocidolite, tremolite-actinolite and anthophyllite.

Asbestos: A term for naturally occurring fibrous minerals. Asbestos includes chrysotile, cummingtonite-grunerite asbestos (amosite), anthophyllite asbestos, tremolite asbestos, crocidolite, actinolite asbestos and any of these minerals which have been chemically treated or altered. The precise chemical formulation of each species varies with the location from which it was mined. Nominal compositions are listed:

Chrysotile........................Mg(3)Si(2)O(5)(OH)(4)

Crocidolite (Riebeckite asbestos) ................................Na(2)Fe(3)(2)+Fe(2)(3)+Si(8)O(2)2(OH)(2)

Cummingtonite-Grunerite asbestos (Amosite) ................................(Mg,Fe)(7)Si(8)O(2)2(OH)(2)

Tremolite-Actinolite asbestos ................................Ca(2)(Mg,Fe)(5)Si(8)O(2)2(OH)(2)

Anthophyllite asbestos ................................(Mg,Fe)(7)Si(8)O(2)2(OH)(2)

Asbestos Fiber: A fiber of asbestos meeting the criteria for a fiber. (See section 3.5.)

Aspect Ratio: The ratio of the length of a fiber to its diameter usually defined as "length : width", e.g. 3:1.

Brucite: A sheet mineral with the composition Mg(OH)(2).

Central Stop Dispersion Staining (microscope): This is a dark field microscope technique that images particles using only light refracted by the particle, excluding light that travels through the particle unrefracted. This is usually accomplished with a McCrone objective or other arrangement which places a circular stop with apparent aperture equal to the objective aperture in the back focal plane of the microscope.

Cleavage Fragments: Mineral particles formed by the comminution of minerals, especially those characterized by relatively parallel sides and moderate aspect ratio.

Differential Counting: The term applied to the practice of excluding certain kinds of fibers from a phase contrast asbestos count because they are not asbestos.

Fiber: A particle longer than or equal to 5 um with a length to width ratio greater than or equal to 3:1. This may include cleavage fragments. (see section 3.5 of this appendix).

Phase Contrast: Contrast obtained in the microscope by causing light scattered by small particles to destructively interfere with unscattered light, thereby enhancing the visibility of very small particles and particles with very low intrinsic contrast.

Phase Contrast Microscope: A microscope configured with a phase mask pair to create phase contrast. The technique which uses this is called Phase Contrast Microscopy (PCM).

Phase-Polar Analysis: This is the use of polarized light in a phase contrast microscope. It is used to see the same size fibers that are visible in air filter analysis. Although fibers finer than 1 um are visible, analysis of these is inferred from analysis of larger bundles that are usually present.

Phase-Polar Microscope: The phase-polar microscope is a phase contrast microscope which has an analyzer, a polarizer, a first order red plate and a rotating phase condenser all in place so that the polarized light image is enhanced by phase contrast.

Sealing Encapsulant: This is a product which can be applied, preferably by spraying, onto an asbestos surface which will seal the surface so that fibers cannot be released.

Serpentine: A mineral family consisting of minerals with the general composition Mg(3)(Si(2)O(5)(OH)(4) having the magnesium in brucite layer over a silicate layer. Minerals important in asbestos analysis included in this family are chrysotile, lizardite, antigorite.

1.1. History

Light microscopy has been used for well over 100 years for the determination of mineral species. This analysis is carried out using specialized polarizing microscopes as well as bright field microscopes. The identification of minerals is an on-going process with many new minerals described each year. The first recorded use of asbestos was in Finland about 2500 B.C. where the material was used in the mud wattle for the wooden huts the people lived in as well as strengthening for pottery. Adverse health aspects of the mineral were noted nearly 2000 years ago when Pliny the Younger wrote about the poor health of slaves in the asbestos mines. Although known to be injurious for centuries, the first modern references to its toxicity were by the British Labor Inspectorate when it banned asbestos dust from the workplace in 1898. Asbestosis cases were described in the literature after the turn of the century. Cancer was first suspected in the mid 1930's and a causal link to mesothelioma was made in 1965. Because of the public concern for worker and public safety with the use of this material, several different types of analysis were applied to the determination of asbestos content. Light microscopy requires a great deal of experience and craft. Attempts were made to apply less subjective methods to the analysis. X-ray diffraction was partially successful in determining the mineral types but was unable to separate out the fibrous portions from the non-fibrous portions. Also, the minimum detection limit for asbestos analysis by X-ray diffraction (XRD) is about 1%. Differential Thermal Analysis (DTA) was no more successful. These provide useful corroborating information when the presence of asbestos has been shown by microscopy; however, neither can determine the difference between fibrous and non-fibrous minerals when both habits are present. The same is true of Infrared Absorption (IR).

When electron microscopy was applied to asbestos analysis, hundreds of fibers were discovered present too small to be visible in any light microscope. There are two different types of electron microscope used for asbestos analysis: Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM). Scanning Electron Microscopy is useful in identifying minerals. The SEM can provide two of the three pieces of information required to identify fibers by electron microscopy: morphology and chemistry. The third is structure as determined by Selected Area Electron Diffraction -- SAED which is performed in the TEM. Although the resolution of the SEM is sufficient for very fine fibers to be seen, accuracy of chemical analysis that can be performed on the fibers varies with fiber diameter in fibers of less than 0.2 um diameter. The TEM is a powerful tool to identify fibers too small to be resolved by light microscopy and should be used in conjunction with this method when necessary. The TEM can provide all three pieces of information required for fiber identification. Most fibers thicker than 1 um can adequately be defined in the light microscope. The light microscope remains as the best instrument for the determination of mineral type. This is because the minerals under investigation were first described analytically with the light microscope. It is inexpensive and gives positive identification for most samples analyzed. Further, when optical techniques are inadequate, there is ample indication that alternative techniques should be used for complete identification of the sample.

1.2. Principle

Minerals consist of atoms that may be arranged in random order or in a regular arrangement. Amorphous materials have atoms in random order while crystalline materials have long range order. Many materials are transparent to light, at least for small particles or for thin sections. The properties of these materials can be investigated by the effect that the material has on light passing through it. The six asbestos minerals are all crystalline with particular properties that have been identified and cataloged. These six minerals are anisotropic. They have a regular array of atoms, but the arrangement is not the same in all directions. Each major direction of the crystal presents a different regularity. Light photons travelling in each of these main directions will encounter different electrical neighborhoods, affecting the path and time of travel. The techniques outlined in this method use the fact that light traveling through fibers or crystals in different directions will behave differently, but predictably. The behavior of the light as it travels through a crystal can be measured and compared with known or determined values to identify the mineral species. Usually, Polarized Light Microscopy (PLM) is performed with strain-free objectives on a bright-field microscope platform. This would limit the resolution of the microscope to about 0.4 um. Because OSHA requires the counting and identification of fibers visible in phase contrast, the phase contrast platform is used to visualize the fibers with the polarizing elements added into the light path. Polarized light methods cannot identify fibers finer than about 1 um in diameter even though they are visible. The finest fibers are usually identified by inference from the presence of larger, identifiable fiber bundles. When fibers are present, but not identifiable by light microscopy, use either SEM or TEM to determine the fiber identity.

1.3. Advantages and Disadvantages

The advantages of light microcopy are:

(a) Basic identification of the materials was first performed by light microscopy and gross analysis. This provides a large base of published information against which to check analysis and analytical technique.

(b) The analysis is specific to fibers. The minerals present can exist in asbestiform, fibrous, prismatic, or massive varieties all at the same time. Therefore, bulk methods of analysis such as X-ray diffraction, IR analysis, DTA, etc. are inappropriate where the material is not known to be fibrous.

(c) The analysis is quick, requires little preparation time, and can be performed on-site if a suitably equipped microscope is available.

The disadvantages are:

(a) Even using phase-polar illumination, not all the fibers present may be seen. This is a problem for very low asbestos concentrations where agglomerations or large bundles of fibers may not be present to allow identification by inference.

(b) The method requires a great degree of sophistication on the part of the microscopist. An analyst is only as useful as his mental catalog of images. Therefore, a microscopist's accuracy is enhanced by experience. The mineralogical training of the analyst is very important. It is the basis on which subjective decisions are made.

(c) The method uses only a tiny amount of material for analysis. This may lead to sampling bias and false results (high or low). This is especially true if the sample is severely inhomogeneous.

(d) Fibers may be bound in a matrix and not distinguishable as fibers so identification cannot be made.

1.4. Method Performance

1.4.1. This method can be used for determination of asbestos content from 0 to 100% asbestos. The detection limit has not been adequately determined, although for selected samples, the limit is very low, depending on the number of particles examined. For mostly homogeneous, finely divided samples, with no difficult fibrous interferences, the detection limit is below 1%. For inhomogeneous samples (most samples), the detection limit remains undefined. NIST has conducted proficiency testing of laboratories on a national scale. Although each round is reported statistically with an average, control limits, etc., the results indicate a difficulty in establishing precision especially in the low concentration range. It is suspected that there is significant bias in the low range especially near 1%. EPA tried to remedy this by requiring a mandatory point counting scheme for samples less than 10%. The point counting procedure is tedious, and may introduce significant biases of its own. It has not been incorporated into this method.

1.4.2. The precision and accuracy of the quantitation tests performed in this method are unknown. Concentrations are easier to determine in commercial products where asbestos was deliberately added because the amount is usually more than a few percent. An analyst's results can be "calibrated" against the known amounts added by the manufacturer. For geological samples, the degree of homogeneity affects the precision.

1.4.3. The performance of the method is analyst dependent. The analyst must choose carefully and not necessarily randomly the portions for analysis to assure that detection of asbestos occurs when it is present. For this reason, the analyst must have adequate training in sample preparation, and experience in the location and identification of asbestos in samples. This is usually accomplished through substantial on-the-job training as well as formal education in mineralogy and microscopy.

1.5. Interferences

Any material which is long, thin, and small enough to be viewed under the microscope can be considered an interference for asbestos. There are literally hundreds of interferences in workplaces. The techniques described in this method are normally sufficient to eliminate the interferences. An analyst's success in eliminating the interferences depends on proper training.

Asbestos minerals belong to two mineral families: the serpentines and the amphiboles. In the serpentine family, the only common fibrous mineral is chrysotile. Occasionally, the mineral antigorite occurs in a fibril habit with morphology similar to the amphiboles. The amphibole minerals consist of a score of different minerals of which only five are regulated by federal standard: amosite, crocidolite, anthophyllite asbestos, tremolite asbestos and actinolite asbestos. These are the only amphibole minerals that have been commercially exploited for their fibrous properties; however, the rest can and do occur occasionally in asbestiform habit.

In addition to the related mineral interferences, other minerals common in building material may present a problem for some microscopists: gypsum, anhydrite, brucite, quartz fibers, talc fibers or ribbons, wollastonite, perlite, attapulgite, etc. Other fibrous materials commonly present in workplaces are: fiberglass, mineral wool, ceramic wool, refractory ceramic fibers, kevlar, nomex, synthetic fibers, graphite or carbon fibers, cellulose (paper or wood) fibers, metal fibers, etc.

Matrix embedding material can sometimes be a negative interference. The analyst may not be able to easily extract the fibers from the matrix in order to use the method. Where possible, remove the matrix before the analysis, taking careful note of the loss of weight. Some common matrix materials are: vinyl, rubber, tar, paint, plant fiber, cement, and epoxy. A further negative interference is that the asbestos fibers themselves may be either too small to be seen in Phase contrast Microscopy (PCM) or of a very low fibrous quality, having the appearance of plant fibers. The analyst's ability to deal with these materials increases with experience.

1.6. Uses and Occupational Exposure

Asbestos is ubiquitous in the environment. More than 40% of the land area of the United States is composed of minerals which may contain asbestos. Fortunately, the actual formation of great amounts of asbestos is relatively rare. Nonetheless, there are locations in which environmental exposure can be severe such as in the Serpentine Hills of California.

There are thousands of uses for asbestos in industry and the home. Asbestos abatement workers are the most current segment of the population to have occupational exposure to great amounts of asbestos. If the material is undisturbed, there is no exposure. Exposure occurs when the asbestos-containing material is abraded or otherwise disturbed during maintenance operations or some other activity. Approximately 95% of the asbestos in place in the United States is chrysotile.

Amosite and crocidolite make up nearly all the difference. Tremolite and anthophyllite make up a very small percentage. Tremolite is found in extremely small amounts in certain chrysotile deposits. Actinolite exposure is probably greatest from environmental sources, but has been identified in vermiculite containing, sprayed-on insulating materials which may have been certified as asbestos-free.

1.7. Physical and Chemical Properties

The nominal chemical compositions for the asbestos minerals were given in Section 1. Compared to cleavage fragments of the same minerals, asbestiform fibers possess a high tensile strength along the fiber axis. They are chemically inert, non- combustible, and heat resistant. Except for chrysotile, they are insoluble in Hydrochloric acid (HCl). Chrysotile is slightly soluble in HCl. Asbestos has high electrical resistance and good sound absorbing characteristics. It can be woven into cables, fabrics or other textiles, or matted into papers, felts, and mats.

1.8. Toxicology (This Section is for Information Only and Should Not Be Taken as OSHA Policy)

Possible physiologic results of respiratory exposure to asbestos are mesothelioma of the pleura or peritoneum, interstitial fibrosis, asbestosis, pneumoconiosis, or respiratory cancer. The possible consequences of asbestos exposure are detailed in the NIOSH Criteria Document or in the OSHA Asbestos Standards 29 CFR 1910.1001 and 29 CFR 1926.1101.

2. Sampling Procedure

2.1. Equipment for Sampling

(a) Tube or cork borer sampling device

(b) Knife

(c) 20 mL scintillation vial or similar vial

(d) Sealing encapsulant

2.2. Safety Precautions

Asbestos is a known carcinogen. Take care when sampling. While in an asbestos-containing atmosphere, a properly selected and fit- tested respirator should be worn. Take samples in a manner to cause the least amount of dust. Follow these general guidelines:

(a) Do not make unnecessary dust.

(b) Take only a small amount (1 to 2 g).

(c) Tightly close the sample container.

(d) Use encapsulant to seal the spot where the sample was taken, if necessary.

2.3. Sampling Procedure

Samples of any suspect material should be taken from an inconspicuous place. Where the material is to remain, seal the sampling wound with an encapsulant to eliminate the potential for exposure from the sample site. Microscopy requires only a few milligrams of material. The amount that will fill a 20 mL scintillation vial is more than adequate. Be sure to collect samples from all layers and phases of material. If possible, make separate samples of each different phase of the material. This will aid in determining the actual hazard. DO NOT USE ENVELOPES, PLASTIC OR PAPER BAGS OF ANY KIND TO COLLECT SAMPLES. The use of plastic bags presents a contamination hazard to laboratory personnel and to other samples. When these containers are opened, a bellows effect blows fibers out of the container onto everything, including the person opening the container.

If a cork-borer type sampler is available, push the tube through the material all the way, so that all layers of material are sampled. Some samplers are intended to be disposable. These should be capped and sent to the laboratory. If a non-disposable cork borer is used, empty the contents into a scintillation vial and send to the laboratory. Vigorously and completely clean the cork borer between samples.

2.4 Shipment

Samples packed in glass vials must not touch or they might break in shipment.

(a) Seal the samples with a sample seal (such as the OSHA 21) over the end to guard against tampering and to identify the sample.

(b) Package the bulk samples in separate packages from the air samples. They may cross-contaminate each other and will invalidate the results of the air samples.

(c) Include identifying paperwork with the samples, but not in contact with the suspected asbestos.

(d) To maintain sample accountability, ship the samples by certified mail, overnight express, or hand carry them to the laboratory.

3. Analysis

The analysis of asbestos samples can be divided into two major parts:

sample preparation and microscopy. Because of the different asbestos uses that may be encountered by the analyst, each sample may need different preparation steps. The choices are outlined below. There are several different tests that are performed to identify the asbestos species and determine the percentage. They will be explained below.

3.1. Safety

(a) Do not create unnecessary dust. Handle the samples in HEPA- filter equipped hoods. If samples are received in bags, envelopes or other inappropriate container, open them only in a hood having a face velocity at or greater than 100 fpm. Transfer a small amount to a scintillation vial and only handle the smaller amount.

(b) Open samples in a hood, never in the open lab area.

(c) Index of refraction oils can be toxic. Take care not to get this material on the skin. Wash immediately with soap and water if this happens.

(d) Samples that have been heated in the muffle furnace or the drying oven may be hot. Handle them with tongs until they are cool enough to handle.

(e) Some of the solvents used, such as THF (tetrahydrofuran), are toxic and should only be handled in an appropriate fume hood and according to instructions given in the Material Safety Data Sheet (MSDS).

3.2. Equipment

(a) Phase contrast microscope with 10x, 16x and 40x objectives, 10x wide-field eyepieces, G-22 Walton-Beckett graticule, Whipple disk, polarizer, analyzer and first order red or gypsum plate, 100 Watt illuminator, rotating position condenser with oversize phase rings, central stop dispersion objective, Kohler illumination and a rotating mechanical stage.

(b) Stereo microscope with reflected light illumination, transmitted light illumination, polarizer, analyzer and first order red or gypsum plate, and rotating stage.

(c) Negative pressure hood for the stereo microscope

(d) Muffle furnace capable of 600 deg.C

(e) Drying oven capable of 50 -- 150 deg.C

(f) Aluminum specimen pans

(g) Tongs for handling samples in the furnace

(h) High dispersion index of refraction oils (Special for dispersion staining.)

n = 1.550

n = 1.585

n = 1.590

n = 1.605

n = 1.620

n = 1.670

n = 1.680

n = 1.690

(i) A set of index of refraction oils from about n=1.350 to n=2.000 in n=0.005 increments. (Standard for Becke line analysis.)

(j) Glass slides with painted or frosted ends 1 x 3 inches 1mm thick, precleaned.

(k) Cover Slips 22 x 22 mm, #1 1/2

(l) Paper clips or dissection needles

(m) Hand grinder

(n) Scalpel with both #10 and #11 blades

(o) 0.1 molar HCl

(p) Decalcifying solution (Baxter Scientific Products) Ethylenediaminetetraacetic Acid,

Tetrasodium................................. 0.7 g/l Sodium Potassium

Tartrate................... 8.0 mg/liter Hydrochloric

Acid........................... 99.2 g/liter Sodium

Tartrate............................. 0.14 g/liter

 

(q) Tetrahydrofuran (THF)

(r) Hotplate capable of 60 deg.C

(s) Balance

(t) Hacksaw blade

(u) Ruby mortar and pestle

3.3. Sample Pre-Preparation

Sample preparation begins with pre-preparation which may include chemical reduction of the matrix, heating the sample to dryness or heating in the muffle furnace. The end result is a sample which has been reduced to a powder that is sufficiently fine to fit under the cover slip. Analyze different phases of samples separately, e.g., tile and the tile mastic should be analyzed separately as the mastic may contain asbestos while the tile may not.

(a) Wet samples

Samples with a high water content will not give the proper dispersion colors and must be dried prior to sample mounting. Remove the lid of the scintillation vial, place the bottle in the drying oven and heat at 100 deg.C to dryness (usually about 2 h). Samples which are not submitted to the lab in glass must be removed and placed in glass vials or aluminum weighing pans before placing them in the drying oven.

(b) Samples With Organic Interference -- Muffle Furnace

These may include samples with tar as a matrix, vinyl asbestos tile, or any other organic that can be reduced by heating. Remove the sample from the vial and weigh in a balance to determine the weight of the submitted portion. Place the sample in a muffle furnace at 500 deg.C for 1 to 2 h or until all obvious organic material has been removed. Retrieve, cool and weigh again to determine the weight loss on ignition. This is necessary to determine the asbestos content of the submitted sample, because the analyst will be looking at a reduced sample.

Note: Heating above 600 deg.C will cause the sample to undergo a structural change which, given sufficient time, will convert the chrysotile to forsterite. Heating even at lower temperatures for 1 to 2 h may have a measurable effect on the optical properties of the minerals. If the analyst is unsure of what to expect, a sample of standard asbestos should be heated to the same temperature for the same length of time so that it can be examined for the proper interpretation.

(c) Samples With Organic Interference -- THF

Vinyl asbestos tile is the most common material treated with this solvent, although, substances containing tar will sometimes yield to this treatment. Select a portion of the material and then grind it up if possible. Weigh the sample and place it in a test tube. Add sufficient THF to dissolve the organic matrix. This is usually about 4 to 5 mL. Remember, THF is highly flammable. Filter the remaining material through a tared silver membrane, dry and weigh to determine how much is left after the solvent extraction. Further process the sample to remove carbonate or mount directly.

(d) Samples With Carbonate Interference

Carbonate material is often found on fibers and sometimes must be removed in order to perform dispersion microscopy. Weigh out a portion of the material and place it in a test tube. Add a sufficient amount of 0.1 M HCl or decalcifying solution in the tube to react all the carbonate as evidenced by gas formation; i.e., when the gas bubbles stop, add a little more solution. If no more gas forms, the reaction is complete. Filter the material out through a tared silver membrane, dry and weigh to determine the weight lost.

3.4. Sample Preparation

Samples must be prepared so that accurate determination can be made of the asbestos type and amount present. The following steps are carried out in the low-flow hood (a low-flow hood has less than 50 fpm flow):

(1) If the sample has large lumps, is hard, or cannot be made to lie under a cover slip, the grain size must be reduced. Place a small amount between two slides and grind the material between them or grind a small amount in a clean mortar and pestle. The choice of whether to use an alumina, ruby, or diamond mortar depends on the hardness of the material. Impact damage can alter the asbestos mineral if too much mechanical shock occurs. (Freezer mills can completely destroy the observable crystallinity of asbestos and should not be used). For some samples, a portion of material can be shaved off with a scalpel, ground off with a hand grinder or hack saw blade.

The preparation tools should either be disposable or cleaned thoroughly. Use vigorous scrubbing to loosen the fibers during the washing. Rinse the implements with copious amounts of water and air- dry in a dust-free environment.

(2) If the sample is powder or has been reduced as in (1) above, it is ready to mount. Place a glass slide on a piece of optical tissue and write the identification on the painted or frosted end. Place two drops of index of refraction medium n=1.550 on the slide. (The medium n=1.550 is chosen because it is the matching index for chrysotile. Dip the end of a clean paper-clip or dissecting needle into the droplet of refraction medium on the slide to moisten it. Then dip the probe into the powder sample. Transfer what sticks on the probe to the slide. The material on the end of the probe should have a diameter of about 3 mm for a good mount. If the material is very fine, less sample may be appropriate. For non-powder samples such as fiber mats, forceps should be used to transfer a small amount of material to the slide. Stir the material in the medium on the slide, spreading it out and making the preparation as uniform as possible. Place a cover-slip on the preparation by gently lowering onto the slide and allowing it to fall "trapdoor" fashion on the preparation to push out any bubbles. Press gently on the cover slip to even out the distribution of particulate on the slide. If there is insufficient mounting oil on the slide, one or two drops may be placed near the edge of the coverslip on the slide. Capillary action will draw the necessary amount of liquid into the preparation. Remove excess oil with the point of a laboratory wiper.

Treat at least two different areas of each phase in this fashion. Choose representative areas of the sample. It may be useful to select particular areas or fibers for analysis. This is useful to identify asbestos in severely inhomogeneous samples.

When it is determined that amphiboles may be present, repeat the above process using the appropriate high-dispersion oils until an identification is made or all six asbestos minerals have been ruled out. Note that percent determination must be done in the index medium 1.550 because amphiboles tend to disappear in their matching mediums.

3.5. Analytical Procedure

Note: This method presumes some knowledge of mineralogy and optical petrography.

The analysis consists of three parts: The determination of whether there is asbestos present, what type is present and the determination of how much is present. The general flow of the analysis is:

(1) Gross examination.

(2) Examination under polarized light on the stereo microscope.

(3) Examination by phase-polar illumination on the compound phase microscope.

(4) Determination of species by dispersion stain. Examination by Becke line analysis may also be used; however, this is usually more cumbersome for asbestos determination.

(5) Difficult samples may need to be analyzed by SEM or TEM, or the results from those techniques combined with light microscopy for a definitive identification. Identification of a particle as asbestos requires that it be asbestiform. Description of particles should follow the suggestion of Campbell. (Figure 1)

(For Figure 1, Particle difinitions showing mineral growth habits, see paper copy)

For the purpose of regulation, the mineral must be one of the six minerals covered and must be in the asbestos growth habit. Large specimen samples of asbestos generally have the gross appearance of wood. Fibers are easily parted from it. Asbestos fibers are very long compared with their widths. The fibers have a very high tensile strength as demonstrated by bending without breaking. Asbestos fibers exist in bundles that are easily parted, show longitudinal fine structure and may be tufted at the ends showing "bundle of sticks" morphology. In the microscope some of these properties may not be observable. Amphiboles do not always show striations along their length even when they are asbestos. Neither will they always show tufting. They generally do not show a curved nature except for very long fibers. Asbestos and asbestiform minerals are usually characterized in groups by extremely high aspect ratios (greater than 100:1). While aspect ratio analysis is useful for characterizing populations of fibers, it cannot be used to identify individual fibers of intermediate to short aspect ratio. Observation of many fibers is often necessary to determine whether a sample consists of "cleavage fragments" or of asbestos fibers.

Most cleavage fragments of the asbestos minerals are easily distinguishable from true asbestos fibers. This is because true cleavage fragments usually have larger diameters than 1 um. Internal structure of particles larger than this usually shows them to have no internal fibrillar structure. In addition, cleavage fragments of the monoclinic amphiboles show inclined extinction under crossed polars with no compensator. Asbestos fibers usually show extinction at zero degrees or ambiguous extinction if any at all. Morphologically, the larger cleavage fragments are obvious by their blunt or stepped ends showing prismatic habit. Also, they tend to be acicular rather than filiform.

Where the particles are less than 1 um in diameter and have an aspect ratio greater than or equal to 3:1, it is recommended that the sample be analyzed by SEM or TEM if there is any question whether the fibers are cleavage fragments or asbestiform particles.

Care must be taken when analyzing by electron microscopy because the interferences are different from those in light microscopy and may structurally be very similar to asbestos. The classic interference is between anthophyllite and biopyribole or intermediate fiber. Use the same morphological clues for electron microscopy as are used for light microscopy, e.g. fibril splitting, internal longitudinal striation, fraying, curvature, etc.

(1) Gross examination:

Examine the sample, preferably in the glass vial. Determine the presence of any obvious fibrous component. Estimate a percentage based on previous experience and current observation. Determine whether any pre-preparation is necessary. Determine the number of phases present. This step may be carried out or augmented by observation at 6 to 40 x under a stereo microscope.

(2) After performing any necessary pre-preparation, prepare slides of each phase as described above. Two preparations of the same phase in the same index medium can be made side-by-side on the same glass for convenience. Examine with the polarizing stereo microscope. Estimate the percentage of asbestos based on the amount of birefringent fiber present.

(3) Examine the slides on the phase-polar microscopes at magnifications of 160 and 400 x . Note the morphology of the fibers. Long, thin, very straight fibers with little curvature are indicative of fibers from the amphibole family. Curved, wavy fibers are usually indicative of chrysotile. Estimate the percentage of asbestos on the phase-polar microscope under conditions of crossed polars and a gypsum plate. Fibers smaller than 1.0 um in thickness must be identified by inference to the presence of larger, identifiable fibers and morphology. If no larger fibers are visible, electron microscopy should be performed. At this point, only a tentative identification can be made. Full identification must be made with dispersion microscopy. Details of the tests are included in the appendices.

(4) Once fibers have been determined to be present, they must be identified. Adjust the microscope for dispersion mode and observe the fibers. The microscope has a rotating stage, one polarizing element, and a system for generating dark-field dispersion microscopy (see Section 4.6. of this appendix). Align a fiber with its length parallel to the polarizer and note the color of the Becke lines. Rotate the stage to bring the fiber length perpendicular to the polarizer and note the color. Repeat this process for every fiber or fiber bundle examined. The colors must be consistent with the colors generated by standard asbestos reference materials for a positive identification. In n=1.550, amphiboles will generally show a yellow to straw-yellow color indicating that the fiber indices of refraction are higher than the liquid. If long, thin fibers are noted and the colors are yellow, prepare further slides as above in the suggested matching liquids listed below:

Type of asbestos Index of refraction
Chrysotile n=1.550
Amosite n=1.670 r 1.680
Crocidolite n=1.690
Anthophyllite n=1.605 nd 1.620
Tremolite n=1.605 and 1.620
Actinolite n=1.620

Where more than one liquid is suggested, the first is preferred;

however, in some cases this liquid will not give good dispersion color. Take care to avoid interferences in the other liquid; e.g., wollastonite in n=1.620 will give the same colors as tremolite. In n=1.605 wollastonite will appear yellow in all directions. Wollastonite may be determined under crossed polars as it will change from blue to yellow as it is rotated along its fiber axis by tapping on the cover slip. Asbestos minerals will not change in this way.

Determination of the angle of extinction may, when present, aid in the determination of anthophyllite from tremolite. True asbestos fibers usually have 0 deg. extinction or ambiguous extinction, while cleavage fragments have more definite extinction.

Continue analysis until both preparations have been examined and all present species of asbestos are identified. If there are no fibers present, or there is less than 0.1% present, end the analysis with the minimum number of slides (2).

(5) Some fibers have a coating on them which makes dispersion microscopy very difficult or impossible. Becke line analysis or electron microscopy may be performed in those cases. Determine the percentage by light microscopy. TEM analysis tends to overestimate the actual percentage present.

(6) Percentage determination is an estimate of occluded area, tempered by gross observation. Gross observation information is used to make sure that the high magnification microscopy does not greatly over- or under- estimate the amount of fiber present. This part of the analysis requires a great deal of experience. Satisfactory models for asbestos content analysis have not yet been developed, although some models based on metallurgical grain-size determination have found some utility. Estimation is more easily handled in situations where the grain sizes visible at about 160 x are about the same and the sample is relatively homogeneous.

View all of the area under the cover slip to make the percentage determination. View the fields while moving the stage, paying attention to the clumps of material. These are not usually the best areas to perform dispersion microscopy because of the interference from other materials. But, they are the areas most likely to represent the accurate percentage in the sample. Small amounts of asbestos require slower scanning and more frequent analysis of individual fields.

Report the area occluded by asbestos as the concentration. This estimate does not generally take into consideration the difference in density of the different species present in the sample. For most samples this is adequate. Simulation studies with similar materials must be carried out to apply microvisual estimation for that purpose and is beyond the scope of this procedure.

(7) Where successive concentrations have been made by chemical or physical means, the amount reported is the percentage of the material in the "as submitted" or original state. The percentage determined by microscopy is multiplied by the fractions remaining after pre-preparation steps to give the percentage in the original sample. For example:

Step 1. 60% remains after heating at 550 deg.C for 1 h.

Step 2. 30% of the residue of step 1 remains after dissolution of carbonate in 0.1 m HCl.

Step 3. Microvisual estimation determines that 5% of the sample is chrysotile asbestos.

The reported result is:

R = (Microvisual result in percent) x (Fraction remaining after step 2) x (Fraction remaining of original sample after step 1) R = (5) x (.30) x (.60)=0.9%

(8) Report the percent and type of asbestos present. For samples where asbestos was identified, but is less than 1.0%, report "Asbestos present, less than 1.0%." There must have been at least two observed fibers or fiber bundles in the two preparations to be reported as present. For samples where asbestos was not seen, report as "None Detected."

Auxiliary Information

Because of the subjective nature of asbestos analysis, certain concepts and procedures need to be discussed in more depth. This information will help the analyst understand why some of the procedures are carried out the way they are.

4.1. Light

Light is electromagnetic energy. It travels from its source in packets called quanta. It is instructive to consider light as a plane wave. The light has a direction of travel. Perpendicular to this and mutually perpendicular to each other, are two vector components. One is the magnetic vector and the other is the electric vector. We shall only be concerned with the electric vector. In this description, the interaction of the vector and the mineral will describe all the observable phenomena. From a light source such a microscope illuminator, light travels in all different direction from the filament.

In any given direction away from the filament, the electric vector is perpendicular to the direction of travel of a light ray. While perpendicular, its orientation is random about the travel axis. If the electric vectors from all the light rays were lined up by passing the light through a filter that would only let light rays with electric vectors oriented in one direction pass, the light would then be POLARIZED.

Polarized light interacts with matter in the direction of the electric vector. This is the polarization direction. Using this property it is possible to use polarized light to probe different materials and identify them by how they interact with light.

The speed of light in a vacuum is a constant at about 2.99 x 10(8) m/s. When light travels in different materials such as air, water, minerals or oil, it does not travel at this speed. It travels slower. This slowing is a function of both the material through which the light is traveling and the wavelength or frequency of the light. In general, the more dense the material, the slower the light travels. Also, generally, the higher the frequency, the slower the light will travel. The ratio of the speed of light in a vacuum to that in a material is called the index of refraction (n). It is usually measured at 589 nm (the sodium D line). If white light (light containing all the visible wavelengths) travels through a material, rays of longer wavelengths will travel faster than those of shorter wavelengths, this separation is called dispersion. Dispersion is used as an identifier of materials as described in Section 4.6.

4.2. Material Properties

Materials are either amorphous or crystalline. The difference between these two descriptions depends on the positions of the atoms in them. The atoms in amorphous materials are randomly arranged with no long range order. An example of an amorphous material is glass. The atoms in crystalline materials, on the other hand, are in regular arrays and have long range order. Most of the atoms can be found in highly predictable locations. Examples of crystalline material are salt, gold, and the asbestos minerals.

It is beyond the scope of this method to describe the different types of crystalline materials that can be found, or the full description of the classes into which they can fall. However, some general crystallography is provided below to give a foundation to the procedures described.

With the exception of anthophyllite, all the asbestos minerals belong to the monoclinic crystal type. The unit cell is the basic repeating unit of the crystal and for monoclinic crystals can be described as having three unequal sides, two 90 deg. angles and one angle not equal to 90 deg.. The orthorhombic group, of which anthophyllite is a member has three unequal sides and three 90 deg. angles. The unequal sides are a consequence of the complexity of fitting the different atoms into the unit cell. Although the atoms are in a regular array, that array is not symmetrical in all directions. There is long range order in the three major directions of the crystal. However, the order is different in each of the three directions. This has the effect that the index of refraction is different in each of the three directions. Using polarized light, we can investigate the index of refraction in each of the directions and identify the mineral or material under investigation. The indices alpha, beta, and gamma are used to identify the lowest, middle, and highest index of refraction respectively. The x direction, associated with alpha is called the fast axis. Conversely, the z direction is associated with gamma and is the slow direction. Crocidolite has alpha along the fiber length making it "length-fast". The remainder of the asbestos minerals have the gamma axis along the fiber length. They are called "length-slow". This orientation to fiber length is used to aid in the identification of asbestos.

4.3. Polarized Light Technique

Polarized light microscopy as described in this section uses the phase-polar microscope described in Section 3.2. A phase contrast microscope is fitted with two polarizing elements, one below and one above the sample. The polarizers have their polarization directions at right angles to each other. Depending on the tests performed, there may be a compensator between these two polarizing elements. A compensator is a piece of mineral with known properties that "compensates" for some deficiency in the optical train. Light emerging from a polarizing element has its electric vector pointing in the polarization direction of the element. The light will not be subsequently transmitted through a second element set at a right angle to the first element. Unless the light is altered as it passes from one element to the other, there is no transmission of light.

4.4. Angle of Extinction

Crystals which have different crystal regularity in two or three main directions are said to be anisotropic. They have a different index of refraction in each of the main directions. When such a crystal is inserted between the crossed polars, the field of view is no longer dark but shows the crystal in color. The color depends on the properties of the crystal. The light acts as if it travels through the crystal along the optical axes. If a crystal optical axis were lined up along one of the polarizing directions (either the polarizer or the analyzer) the light would appear to travel only in that direction, and it would blink out or go dark. The difference in degrees between the fiber direction and the angle at which it blinks out is called the angle of extinction. When this angle can be measured, it is useful in identifying the mineral. The procedure for measuring the angle of extinction is to first identify the polarization direction in the microscope. A commercial alignment slide can be used to establish the polarization directions or use anthophyllite or another suitable mineral. This mineral has a zero degree angle of extinction and will go dark to extinction as it aligns with the polarization directions. When a fiber of anthophyllite has gone to extinction, align the eyepiece reticle or graticule with the fiber so that there is a visual cue as to the direction of polarization in the field of view. Tape or otherwise secure the eyepiece in this position so it will not shift.

After the polarization direction has been identified in the field of view, move the particle of interest to the center of the field of view and align it with the polarization direction. For fibers, align the fiber along this direction. Note the angular reading of the rotating stage. Looking at the particle, rotate the stage until the fiber goes dark or "blinks out". Again note the reading of the stage. The difference in the first reading and the second is an angle of extinction.

The angle measured may vary as the orientation of the fiber changes about its long axis. Tables of mineralogical data usually report the maximum angle of extinction. Asbestos forming minerals, when they exhibit an angle of extinction, usually do show an angle of extinction close to the reported maximum, or as appropriate depending on the substitution chemistry.

4.5. Crossed Polars with Compensator

When the optical axes of a crystal are not lined up along one of the polarizing directions (either the polarizer or the analyzer) part of the light travels along one axis and part travels along the other visible axis. This is characteristic of birefringent materials.

The color depends on the difference of the two visible indices of refraction and the thickness of the crystal. The maximum difference available is the difference between the alpha and the gamma axes. This maximum difference is usually tabulated as the birefringence of the crystal.

For this test, align the fiber at 45 deg. to the polarization directions in order to maximize the contribution to each of the optical axes. The colors seen are called retardation colors. They arise from the recombination of light which has traveled through the two separate directions of the crystal. One of the rays is retarded behind the other since the light in that direction travels slower. On recombination, some of the colors which make up white light are enhanced by constructive interference and some are suppressed by destructive interference. The result is a color dependent on the difference between the indices and the thickness of the crystal. The proper colors, thicknesses, and retardations are shown on a Michel- Levy chart. The three items, retardation, thickness and birefringence are related by the following relationship:

R = t(n gamma -- n alpha) R = retardation, t = crystal thickness in um, and n alpha, n alpha, gamma = indices of refraction.

Examination of the equation for asbestos minerals reveals that the visible colors for almost all common asbestos minerals and fiber sizes are shades of gray and black. The eye is relatively poor at discriminating different shades of gray. It is very good at discriminating different colors. In order to compensate for the low retardation, a compensator is added to the light train between the polarization elements. The compensator used for this test is a gypsum plate of known thickness and birefringence. Such a compensator when oriented at 45 deg. to the polarizer direction, provides a retardation of 530 nm of the 530 nm wavelength color. This enhances the red color and gives the background a characteristic red to red-magenta color. If this "full-wave" compensator is in place when the asbestos preparation is inserted into the light train, the colors seen on the fibers are quite different. Gypsum, like asbestos has a fast axis and a slow axis. When a fiber is aligned with its fast axis in the same direction as the fast axis of the gypsum plate, the ray vibrating in the slow direction is retarded by both the asbestos and the gypsum. This results in a higher retardation than would be present for either of the two minerals. The color seen is a second order blue. When the fiber is rotated 90 deg. using the rotating stage, the slow direction of the fiber is now aligned with the fast direction of the gypsum and the fast direction of the fiber is aligned with the slow direction of the gypsum. Thus, one ray vibrates faster in the fast direction of the gypsum, and slower in the slow direction of the fiber; the other ray will vibrate slower in the slow direction of the gypsum and faster in the fast direction of the fiber. In this case, the effect is subtractive and the color seen is a first order yellow. As long as the fiber thickness does not add appreciably to the color, the same basic colors will be seen for all asbestos types except crocidolite. In crocidolite the colors will be weaker, may be in the opposite directions, and will be altered by the blue absorption color natural to crocidolite. Hundreds of other materials will give the same colors as asbestos, and therefore, this test is not definitive for asbestos. The test is useful in discriminating against fiberglass or other amorphous fibers such as some synthetic fibers. Certain synthetic fibers will show retardation colors different than asbestos; however, there are some forms of polyethylene and aramid which will show morphology and retardation colors similar to asbestos minerals. This test must be supplemented with a positive identification test when birefringent fibers are present which can not be excluded by morphology. This test is relatively ineffective for use on fibers less than 1 um in diameter. For positive confirmation TEM or SEM should be used if no larger bundles or fibers are visible.

4.6. Dispersion Staining

Dispersion microscopy or dispersion staining is the method of choice for the identification of asbestos in bulk materials. Becke line analysis is used by some laboratories and yields the same results as does dispersion staining for asbestos and can be used in lieu of dispersion staining. Dispersion staining is performed on the same platform as the phase-polar analysis with the analyzer and compensator removed. One polarizing element remains to define the direction of the light so that the different indices of refraction of the fibers may be separately determined. Dispersion microscopy is a dark-field technique when used for asbestos. Particles are imaged with scattered light. Light which is unscattered is blocked from reaching the eye either by the back field image mask in a McCrone objective or a back field image mask in the phase condenser. The most convenient method is to use the rotating phase condenser to move an oversized phase ring into place. The ideal size for this ring is for the central disk to be just larger than the objective entry aperture as viewed in the back focal plane. The larger the disk, the less scattered light reaches the eye. This will have the effect of diminishing the intensity of dispersion color and will shift the actual color seen. The colors seen vary even on microscopes from the same manufacturer. This is due to the different bands of wavelength exclusion by different mask sizes. The mask may either reside in the condenser or in the objective back focal plane. It is imperative that the analyst determine by experimentation with asbestos standards what the appropriate colors should be for each asbestos type. The colors depend also on the temperature of the preparation and the exact chemistry of the asbestos. Therefore, some slight differences from the standards should be allowed. This is not a serious problem for commercial asbestos uses. This technique is used for identification of the indices of refraction for fibers by recognition of color. There is no direct numerical readout of the index of refraction. Correlation of color to actual index of refraction is possible by referral to published conversion tables. This is not necessary for the analysis of asbestos. Recognition of appropriate colors along with the proper morphology are deemed sufficient to identify the commercial asbestos minerals. Other techniques including SEM, TEM, and XRD may be required to provide additional information in order to identify other types of asbestos.

Make a preparation in the suspected matching high dispersion oil, e.g., n=1.550 for chrysotile. Perform the preliminary tests to determine whether the fibers are birefringent or not. Take note of the morphological character. Wavy fibers are indicative of chrysotile while long, straight, thin, frayed fibers are indicative of amphibole asbestos. This can aid in the selection of the appropriate matching oil. The microscope is set up and the polarization direction is noted as in Section 4.4. Align a fiber with the polarization direction. Note the color. This is the color parallel to the polarizer. Then rotate the fiber rotating the stage 90 deg. so that the polarization direction is across the fiber. This is the perpendicular position. Again note the color. Both colors must be consistent with standard asbestos minerals in the correct direction for a positive identification of asbestos. If only one of the colors is correct while the other is not, the identification is not positive. If the colors in both directions are bluish-white, the analyst has chosen a matching index oil which is higher than the correct matching oil, e.g. the analyst has used n=1.620 where chrysotile is present. The next lower oil (Section 3.5.) should be used to prepare another specimen. If the color in both directions is yellow-white to straw-yellow-white, this indicates that the index of the oil is lower than the index of the fiber, e.g. the preparation is in n=1.550 while anthophyllite is present. Select the next higher oil (Section 3.5.) and prepare another slide. Continue in this fashion until a positive identification of all asbestos species present has been made or all possible asbestos species have been ruled out by negative results in this test. Certain plant fibers can have similar dispersion colors as asbestos. Take care to note and evaluate the morphology of the fibers or remove the plant fibers in pre-preparation. Coating material on the fibers such as carbonate or vinyl may destroy the dispersion color. Usually, there will be some outcropping of fiber which will show the colors sufficient for identification. When this is not the case, treat the sample as described in Section 3.3. and then perform dispersion staining. Some samples will yield to Becke line analysis if they are coated or electron microscopy can be used for identification.

5. References

5.1. Crane, D.T., Asbestos in Air, OSHA method ID160, Revised November 1992.

5.2. Ford, W.E., Dana's Textbook of Mineralogy; Fourth Ed.; John Wiley and Son, New York, 1950, p. vii.

5.3. Selikoff,.I.J., Lee, D.H.K., Asbestos and Disease, Academic Press, New York, 1978, pp. 3,20.

5.4. Women Inspectors of Factories. Annual Report for 1898, H.M. Statistical Office, London, p. 170 (1898).

5.5. Selikoff, I.J., Lee, D.H.K., Asbestos and Disease, Academic Press, New York, 1978, pp. 26,30.

5.6. Campbell, W.J., et al, Selected Silicate Minerals and Their Asbestiform Varieties, United States Department of the Interior, Bureau of Mines, Information Circular 8751, 1977.

5.7. Asbestos, Code of Federal Regulations, 29 CFR 1910.1001 and 29 CFR 1926.58.

5.8. National Emission Standards for Hazardous Air Pollutants; Asbestos NESHAP Revision, Federal Register, Vol. 55, No. 224, 20 November 1990, p. 48410.

5.9. Ross, M. The Asbestos Minerals: Definitions, Description, Modes of Formation, Physical and Chemical Properties and Health Risk to the Mining Community, Nation Bureau of Standards Special Publication, Washington, D.C., 1977.

5.10. Lilis, R., Fibrous Zeolites and Endemic Mesothelioma in Cappadocia, Turkey, J. Occ Medicine, 1981, 23,(8),548-550.

5.11. Occupational Exposure to Asbestos -- 1972, U.S. Department of Health, Education and Welfare, Public Health Service, Center for Disease Control, National Institute for Occupational Safety and Health, HSM-72-10267.

5.12. Campbell, W.J., et al, Relationship of Mineral Habit to Size Characteristics for Tremolite Fragments and Fibers, United States Department of the Interior, Bureau of Mines, Information Circular 8367, 1979.

5.13. Mefford, D., DCM Laboratory, Denver, private communication, July 1987.

5.14. Deer, W.A., Howie, R.A., Zussman, J., Rock Forming Minerals, Longman, Thetford, UK, 1974.

5.15. Kerr, P.F., Optical Mineralogy; Third Ed. McGraw-Hill, New York, 1959.

5.16. Veblen, D.R. (Ed.), Amphiboles and Other Hydrous Pyriboles -- Mineralogy, Reviews in Mineralogy, Vol 9A, Michigan, 1982, pp 1-102.

5.17. Dixon, W.C., Applications of Optical Microscopy in the Analysis of Asbestos and Quartz, ACS Symposium Series, No. 120, Analytical Techniques in Occupational Health Chemistry, 1979.

5.18. Polarized Light Microscopy, McCrone Research Institute, Chicago, 1976.

5.19. Asbestos Identification, McCrone Research Institute, G&G printers, Chicago, 1987.

5.20. McCrone, W.C., Calculation of Refractive Indices from Dispersion Staining Data, The Microscope, No 37, Chicago, 1989.

5.21. Levadie, B. (Ed.), Asbestos and Other Health Related Silicates, ASTM Technical Publication 834, ASTM, Philadelphia 1982.

5.22. Steel, E. and Wylie, A., Riordan, P.H. (Ed.), Mineralogical Characteristics of Asbestos, Geology of Asbestos Deposits, pp. 93-101, SME-AIME, 1981.

5.23. Zussman, J., The Mineralogy of Asbestos, Asbestos: Properties, Applications and Hazards, pp. 45-67 Wiley, 1979.

Shipyards

PART 1915 -- [AMENDED]

1. The authority citation of 29 CFR part 1915 continues to read as follows:

Authority: Sec. 41, Longshore and Harbor Workers Compensation Act (33 U.S.C. 941); secs. 4, 6, 8, Occupational Safety and Health Act of 1970 (29 U.S.C. 653, 655, 657); sec. 4 of the Administrative Procedure Act (5 U.S.C. 553); Secretary of Labor's Order No. 12-71 (36 FR 8754), 8-76 (41 FR 35736) or 1-90 (55 FR 9033), as applicable; 29 CFR part 1911.

2. Section 1915.1001 is revised to read as follows:

1915.1001 Asbestos.

(a) Scope and application. This section regulates asbestos exposure in all shipyard employment work as defined in 29 CFR 1915, including but not limited to the following:

(1) Demolition or salvage of structures, vessels, and vessel sections where asbestos is present;

(2) Removal or encapsulation of materials containing asbestos;

(3) Construction, alteration, repair, maintenance, or renovation of vessels, vessel sections, structures, substrates, or portions thereof, that contain asbestos;

(4) Installation of products containing asbestos;

(5) Asbestos spill/emergency cleanup; and

(6) Transportation, disposal, storage, containment of and housekeeping activities involving asbestos or products containing asbestos, on the site or location at which construction activities are performed.

(7) Coverage under this standard shall be based on the nature of the work operation involving asbestos exposure.

(b) Definitions. "Aggressive" method means removal or disturbance of building/vessel materials by sanding, abrading, grinding, or other method that breaks, crumbles, or otherwise disintegrates intact ACM.

"Amended water" means water to which surfactant (wetting agent) has been added to increase the ability of the liquid to penetrate ACM.

"Asbestos" includes chrysotile, amosite, crocidolite, tremolite asbestos, anthophyllite asbestos, actinolite asbestos, and any of these minerals that has been chemically treated and/or altered. For purposes of this standard, "asbestos" includes PACM, as defined below.

"Asbestos-containing material, (ACM)" means any material containing more than one percent asbestos.

"Assistant Secretary" means the Assistant Secretary of Labor for Occupational Safety and Health, U.S. Department of Labor, or designee.

"Authorized person" means any person authorized by the employer and required by work duties to be present in regulated areas.

"Building/facility owner" is the legal entity, including a lessee, which exercises control over management and record keeping functions relating to a building and/or facility in which activities covered by this standard take place.

"Certified Industrial Hygienist (CIH)" means one certified in the comprehensive practice of industrial hygiene by the American Board of Industrial Hygiene.

"Class I asbestos work" means activities involving the removal of thermal system insulation or surfacing ACM/PACM.

"Class II asbestos work" means activities involving the removal of ACM which is neither TSI or surfacing ACM. This includes, but is not limited to, the removal of asbestos-containing wallboard, floor tile and sheeting, roofing and siding shingles, and construction mastics.

"Class III asbestos work means" repair and maintenance operations, where "ACM", including TSI and surfacing ACM and PACM, may be disturbed.

"Class IV asbestos work" means maintenance and custodial activities during which employees contact ACM and PACM and activities to clean up waste and debris containing ACM and PACM.

"Clean room" means an uncontaminated room having facilities for the storage of employees' street clothing and uncontaminated materials and equipment.

"Closely resemble" means that the major workplace conditions which have contributed to the levels of historic asbestos exposure, are no more protective than conditions of the current workplace.

"Competent person" see "Qualified person"

"Critical barrier" means one or more layers of plastic sealed over all openings into a work area or any other physical barrier sufficient to prevent airborne asbestos in a work area from migrating to an adjacent area.

"Decontamination area" means an enclosed area adjacent and connected to the regulated area and consisting of an equipment room, shower area, and clean room, which is used for the decontamination of workers, materials, and equipment that are contaminated with asbestos.

"Demolition" means the wrecking or taking out of any load-supporting structural member and any related razing, removing, or stripping of asbestos products.

"Director" means the Director, National Institute for Occupational Safety and Health, U.S. Department of Health and Human Services, or designee.

"Disturbance" means contact which releases fibers from ACM or PACM or debris containing ACM or PACM. This term includes activities that disrupt the matrix of ACM or PACM, render ACM or PACM friable, or generate visible debris. Disturbance includes cutting away small amounts of ACM and PACM, no greater than the amount which can be contained in one standard sized glove bag or waste bag, in order to access a building or vessel component. In no event shall the amount of ACM or PACM so disturbed exceed that which can be contained in one glove bag or waste bag which shall not exceed 60 inches in length and width.

"Employee exposure" means that exposure to airborne asbestos that would occur if the employee were not using respiratory protective equipment.

"Equipment room (change room)" means a contaminated room located within the decontamination area that is supplied with impermeable bags or containers for the disposal of contaminated protective clothing and equipment.

"Fiber" means a particulate form of asbestos, 5 micrometers or longer, with a length-to-diameter ratio of at least 3 to 1.

"Glovebag" means an impervious plastic bag-like enclosure affixed around an asbestos-containing material, with glove-like appendages through which material and tools may be handled.

"High-efficiency particulate air (HEPA) filter" means a filter capable of trapping and retaining at least 99.97 percent of all mono-dispersed particles of 0.3 micrometers in diameter.

"Homogeneous area" means an area of surfacing material or thermal system insulation that is uniform in color and texture.

"Industrial hygienist" means a professional qualified by education, training, and experience to anticipate, recognize, evaluate and develop controls for occupational health hazards.

"Intact" means that the ACM has not crumbled, been pulverized, or otherwise deteriorated so that it is no longer likely to be bound with its matrix.

"Modification for purposes of paragraph (g)(6)(2)," means a changed or altered procedure, material or component of a control system, which replaces a procedure, material or component of a required system. Omitting a procedure or component, or reducing or diminishing the stringency or strength of a material or component of the control system is not a "modification" for purposes of paragraph (g)(6)(ii) of this section.

"Negative Initial Exposure Assessment" means a demonstration by the employer, which complies with the criteria in paragraph (f)(iii) of this section, that employee exposure during an operation is expected to be consistently below the PELs.

"PACM" means "presumed asbestos containing material". "Presumed Asbestos Containing Material" means thermal system insulation and surfacing material found in buildings, vessels, and vessel sections constructed no later than 1980. The designation of a material as "PACM" may be rebutted pursuant to paragraph (k)(4) of this section.

"Project Designer" means a person who has successfully completed the training requirements for an abatement project designer established by 40 U.S.C. Sec. 763.90(g).

"Qualified person" means, in addition to the definition in 29 CFR 1926.32(f), one who is capable of identifying existing asbestos hazards in the workplace and selecting the appropriate control strategy for asbestos exposure, who has the authority to take prompt corrective measures to eliminate them, as specified in 29 CFR 1926.32(f); in addition, for Class I, II, III, and IV work, who is specially trained in a training course which meet the criteria of EPA's Model Accreditation Plan (40 CFR Part 763) for project designer or supervisor, or its equivalent.

"Regulated area" means an area established by the employer to demarcate areas where Class I, II, and III asbestos work is conducted, and any adjoining area where debris and waste from such asbestos work accumulate; and a work area within which airborne concentrations of asbestos, exceed or can reasonably be expected to exceed the permissible exposure limit. Requirements for regulated areas are set out in paragraph (e)(6) of this section.

"Removal" means all operations where ACM and/or PACM is taken out or stripped from structures or substrates, and includes demolition operations.

"Renovation" means the modifying of any existing vessel, vessel section, structure, or portion thereof.

"Repair" means overhauling, rebuilding, reconstructing, or reconditioning of vessels, vessel sections, structures or substrates, including encapsulation or other repair of ACM or PACM attached to structures or substrates.

"Surfacing material" means material that is sprayed, troweled-on or otherwise applied to surfaces (such as acoustical plaster on ceilings and fireproofing materials on structural members, or other materials on surfaces for acoustical, fireproofing, and other purposes).

"Surfacing ACM" means surfacing material which contains more than 1% asbestos.

"Thermal system insulation (TSI)" means ACM applied to pipes, fittings, boilers, breeching, tanks, ducts or other structural components to prevent heat loss or gain.

"Thermal system insulation ACM" is thermal system insulation which contains more than 1% asbestos.

(c) Permissible exposure limits (PELS) -- (1) Time-weighted average limit (TWA). The employer shall ensure that no employee is exposed to an airborne concentration of asbestos in excess of 0.1 fiber per cubic centimeter of air as an eight (8) hour time-weighted average (TWA), as determined by the method prescribed in Appendix A of this section, or by an equivalent method.

(2) Excursion limit. The employer shall ensure that no employee is exposed to an airborne concentration of asbestos in excess of 1.0 fiber per cubic centimeter of air (1 f/cc) as averaged over a sampling period of thirty (30) minutes, as determined by the method prescribed in Appendix A of this section, or by an equivalent method.

(d) Multi-employer worksites. (1) On multi-employer worksites, an employer performing work requiring the establishment of a regulated area shall inform other employers on the site of the nature of the employer's work with asbestos and/or PACM, of the existence of and requirements pertaining to regulated areas, and the measures taken to ensure that employees of such other employers are not exposed to asbestos.

(2) Asbestos hazards at a multi-employer work site shall be abated by the contractor who created or controls the source of asbestos contamination. For example, if there is a significant breach of an enclosure containing Class I work, the employer responsible for erecting the enclosure shall repair the breach immediately.

(3) In addition, all employers of employees exposed to asbestos hazards shall comply with applicable protective provisions to protect their employees. For example, if employees working immediately adjacent to a Class I asbestos job are exposed to asbestos due to the inadequate containment of such job, their employer shall either remove the employees from the area until the enclosure breach is repaired; or perform an initial exposure assessment pursuant to paragraph (f)(1) of this section.

(4) All employers of employees working adjacent to regulated areas established by another employer on a multi-employer work- site, shall take steps on a daily basis to ascertain the integrity of the enclosure and/or the effectiveness of the control method relied on by the primary asbestos contractor to assure that asbestos fibers do not migrate to such adjacent areas.

(5) All general contractors on a shipyard project which includes work covered by this standard shall be deemed to exercise general supervisory authority over the work covered by this standard, even though the general contractor is not qualified to serve as the asbestos "qualified person" as defined by paragraph (b) of this section. As supervisor of the entire project, the general contractor shall ascertain whether the asbestos contractor is in compliance with this standard, and shall require such contractor to come into compliance with this standard when necessary.

(e) Regulated areas (1) All Class I, II and III asbestos work shall be conducted within regulated areas. All other operations covered by this standard shall be conducted within a regulated area where airborne concentrations of asbestos exceed, or there is a reasonable possibility they may exceed a PEL. Regulated areas shall comply with the requirements of paragraphs (e)(2), (3), (4) and (5) of this section.

(2) Demarcation. The regulated area shall be demarcated in any manner that minimizes the number of persons within the area and protects persons outside the area from exposure to airborne concentrations of asbestos. Where critical barriers or negative pressure enclosures are used, they may demarcate the regulated area. Signs shall be provided and displayed pursuant to the requirements of paragraph (k)(6) of this section.

(3) Access. Access to regulated areas shall be limited to authorized persons and to persons authorized by the Act or regulations issued pursuant thereto.

(4) Respirators. All persons entering a regulated area where employees are required pursuant to paragraph (h)(2) of this section to wear respirators shall be supplied with a respirator selected in accordance with paragraph (h)(2) of this section.

(5) Prohibited activities. The employer shall ensure that employees do not eat, drink, smoke, chew tobacco or gum, or apply cosmetics in the regulated area.

(6) Qualified Persons. The employer shall ensure that all asbestos work performed within regulated areas is supervised by a qualified person, as defined in paragraph (b) of this section. The duties of the qualified person are set out in paragraph (o) of this section.

(f) Exposure assessments and monitoring -- (1) General monitoring criteria.

(i) Each employer who has a workplace of work operation where exposure monitoring is required under this section shall perform monitoring to determine accurately the airborne concentrations of asbestos to which employees may be exposed.

(ii) Determinations of employee exposure shall be made from breathing zone air samples that are representative of the 8-hour TWA and 30-minute short-term exposures of each employee.

(iii) Representative 8-hour TWA employee exposure shall be determined on the basis of one or more samples representing full-shift exposure for employees in each work area. Representative 30-minute short-term employee exposures shall be determined on the basis of one or more samples representing 30 minute exposures associated with operations that are most likely to produce exposures above the excursion limit for employees in each work area.

(2) Initial Exposure Assessment.

(i) Each employer who has a workplace or work operation covered by this standard shall ensure that a "qualified person" conducts an exposure assessment immediately before or at the initiation of the operation to ascertain expected exposures during that operation or workplace. The assessment must be completed in time to comply with requirements which are triggered by exposure data or the lack of a "negative exposure assessment," and to provide information necessary to assure that all control systems planned are appropriate for that operation and will work properly.

(ii) Basis of Initial Exposure Assessment: The initial exposure assessment shall be based on data derived from the following sources:

(A) If feasible, the employer shall monitor employees and base the exposure assessment on the results of exposure monitoring which is conducted pursuant to the criteria in paragraph (f)(2)(iii) of this section.

(B) In addition, the assessment shall include consideration of all observations, information or calculations which indicate employee exposure to asbestos, including any previous monitoring conducted in the workplace, or of the operations of the employer which indicate the levels of airborne asbestos likely to be encountered on the job. However, the assessment may conclude that exposures are likely to be consistently below the PELs only as a conclusion of a "negative exposure assessment" conducted pursuant to paragraph (f)(2)(iii) of this section.

(C) For Class I asbestos work, until the employer conducts exposure monitoring and documents that employees on that job will not be exposed in excess of the PELs, or otherwise makes a negative exposure assessment pursuant to paragraph (f)(2)(iii) of this section, the employer shall presume that employees are exposed in excess of the TWA and excursion limit.

(iii) Negative Initial Exposure Assessment: For any one specific asbestos job which will be performed by employees who have been trained in compliance with the standard, the employer may demonstrate that employee exposures will be below the PELs by data which conform to the following criteria;

(A) Objective data demonstrating that the product or material containing asbestos minerals or the activity involving such product or material cannot release airborne fibers in concentrations exceeding the TWA and excursion limit under those work conditions having the greatest potential for releasing asbestos; or

(B) Where the employer has monitored prior asbestos jobs for the PEL and the excursion limit within 12 months of the current or projected job, the monitoring and analysis were performed in compliance with the asbestos standard in effect; and the data were obtained during work operations conducted under workplace conditions "closely resembling" the processes, type of material, control methods, work practices, and environmental conditions used and prevailing in the employer's current operations, the operations were conducted by employees whose training and experience are no more extensive than that of employees performing the current job, and these data show that under the conditions prevailing and which will prevail in the current workplace there is a high degree of certainty that employee exposures will not exceed the TWA and excursion limit; or

(C) The results of initial exposure monitoring of the current job made from breathing zone air samples that are representative of the 8- hour TWA and 30-minute short-term exposures of each employee covering operations which are most likely during the performance of the entire asbestos job to result in exposures over the PELs.

(3) Periodic monitoring.

(i) Class I and II operations. The employer shall conduct daily monitoring that is representative of the exposure of each employee who is assigned to work within a regulated area who is performing Class I or II work, unless the employer pursuant to paragraph (f)(2)(iii) of this section, has made a negative exposure assessment for the entire operation.

(ii) All operations under the standard other than Class I and II operations. The employer shall conduct periodic monitoring of all work where exposures are expected to exceed a PEL, at intervals sufficient to document the validity of the exposure prediction.

(iii) Exception: When all employees required to be monitored daily are equipped with supplied-air respirators operated in the positive- pressure mode, the employer may dispense with the daily monitoring required by this paragraph. However, employees performing Class I work using a control method which is not listed in paragraph (g)(4)(i), (ii), or (iii) of this section or using a modification of a listed control method, shall continue to be monitored daily even if they are equipped with supplied-air respirators.

(4)(i) Termination of monitoring. If the periodic monitoring required by paragraph (f)(3) of this section reveals that employee exposures, as indicated by statistically reliable measurement, are below the permissible exposure limit and excursion limit the employer may discontinue monitoring for those employees whose exposures are represented by such monitoring.

(ii) Additional monitoring. Notwithstanding the provisions of paragraph (f)(2) and (3), and (f)(4) of this section, the employer shall institute the exposure monitoring required under paragraph (f)(3) of this section whenever there has been a change in process, control equipment, personnel or work practices that may result in new or additional exposures above the permissible exposure limit and/or excursion limit or when the employer has any reason to suspect that a change may result in new or additional exposures above the permissible exposure limit and/or excursion limit. Such additional monitoring is required regardless of whether a "negative exposure assessment" was previously produced for a specific job.

(5) Observation of monitoring.

(i) The employer shall provide affected employees and their designated representatives an opportunity to observe any monitoring of employee exposure to asbestos conducted in accordance with this section.

(ii) When observation of the monitoring of employee exposure to asbestos requires entry into an area where the use of protective clothing or equipment is required, the observer shall be provided with and be required to use such clothing and equipment and shall comply with all other applicable safety and health procedures.

(g) Methods of compliance -- (1) Engineering controls and work practices for all operations covered by this section. The employer shall use the following engineering controls and work practices in all operations covered by this section, regardless of the levels of exposure:

(i) Vacuum cleaners equipped with HEPA filters to collect all debris and dust containing ACM or PACM; and,

(ii) Wet methods, or wetting agents, to control employee exposures during asbestos handling, mixing, removal, cutting, application, and cleanup, except where employers demonstrate that the use of wet methods is infeasible due to for example, the creation of electrical hazards, equipment malfunction, and, in roofing, slipping hazards; and

(iii) Prompt clean-up and disposal of wastes and debris contaminated with asbestos in leak-tight containers.

(2) In addition to the requirements of paragraph (g)(1) of this section above, the employer shall use the following control methods to achieve compliance with the TWA permissible exposure limit and excursion limit prescribed by paragraph (c) of this section;

(i) Local exhaust ventilation equipped with HEPA filter dust collection systems;

(ii) Enclosure or isolation of processes producing asbestos dust;

(iii) Ventilation of the regulated area to move contaminated air away from the breathing zone of employees and toward a filtration or collection device equipped with a HEPA filter;

(iv) Use of other work practices and engineering controls that the Assistant Secretary can show to be feasible.

(v) Wherever the feasible engineering and work practice controls described above are not sufficient to reduce employee exposure to or below the permissible exposure limit and/or excursion limit prescribed in paragraph (c) of this section, the employer shall use them to reduce employee exposure to the lowest levels attainable by these controls and shall supplement them by the use of respiratory protection that complies with the requirements of paragraph (h) of this section.

(3) Prohibitions. The following work practices and engineering controls shall not be used for work related to asbestos or for work which disturbs ACM or PACM, regardless of measured levels of asbestos exposure or the results of initial exposure assessments:

(i) High-speed abrasive disc saws that are not equipped with point of cut ventilator or enclosures with HEPA filtered exhaust air.

(ii) Compressed air used to remove asbestos, or materials containing asbestos, unless the compressed air is used in conjunction with an enclosed ventilation system designed to capture the dust cloud created by the compressed air.

(iii) Dry sweeping, shoveling or other dry clean-up of dust and debris containing ACM and PACM.

(iv) Employee rotation as a means of reducing employee exposure to asbestos.

(4) Class I Requirements. In addition to the provisions of paragraphs (g)(1) and (2) of this section, the following engineering controls and work practices and procedures shall be used.

(i) All Class I work, including the installation and operation of the control system shall be supervised by a qualified person as defined in paragraph (b) of this section;

(ii) For all Class I jobs involving the removal of more than 25 linear or 10 square feet of TSI or surfacing ACM or PACM; for all other Class I jobs, where the employer cannot produce a negative exposure assessment pursuant to paragraph (f)(2)(iii) of this section, or where employees are working in areas adjacent to the regulated area, while the Class I work is being performed, the employer shall use one of the following methods to ensure that airborne asbestos does not migrate from the regulated area:

(A) Critical barriers shall be placed over all openings to the regulated area: or

(B) The employer shall use another barrier or isolation method which prevents the migration of airborne asbestos from the regulated area, as verified by perimeter area surveillance during each work shift at each boundary of the regulated area, showing no visible asbestos dust; and perimeter area monitoring showing that clearance levels contained in 40 CFR Part 763, Subpart E of the EPA Asbestos in Schools Rule are met, or that perimeter area levels, measured by (PCM) are no more than background levels representing the same area before the asbestos work began. The results of such monitoring shall be made known to the employer no later than 24 hours from the end of the work shift represented by such monitoring.

(iii) For all Class I jobs, HVAC systems shall be isolated in the regulated area by sealing with a double layer of 6 mil plastic or the equivalent;

(iv) For all Class I jobs, impermeable dropcloths shall be placed on surfaces beneath all removal activity;

(v) For all Class I jobs, all objects within the regulated area shall be covered with impermeable dropcloths or plastic sheeting which is secured by duct tape or an equivalent.

(vi) For all Class I jobs where the employer cannot produce a negative exposure assessment or where exposure monitoring shows the PELs are exceeded, the employer shall ventilate the regulated area to move contaminated air away from the breathing zone of employees toward a HEPA filtration or collection device.

(5) Specific Control Systems for Class I Work. In addition, Class I asbestos work shall be performed using one or more of the following control methods pursuant to the limitations stated below:

(i) Negative Pressure Enclosure (NPE) systems: NPE systems shall be used where the configuration of the work area does not make the erection of the enclosure infeasible, with the following specifications and work practices.

(A) Specifications:

(1) The negative pressure enclosure (NPE) may be of any configuration,

(2) At least 4 air changes per hour shall be maintained in the NPE,

(3) A minimum of -0.02 column inches of water pressure differential, relative to outside pressure, shall be maintained within the NPE as evidenced by manometric measurements,

(4) The NPE shall be kept under negative pressure throughout the period of its use, and

(5) Air movement shall be directed away from employees performing asbestos work within the enclosure, and toward a HEPA filtration or a collection device.

(B) Work Practices:

(1) Before beginning work within the enclosure and at the beginning of each shift, the NPE shall inspected for breaches and smoke-tested for leaks, and any leaks sealed.

(2) Electrical circuits in the enclosure shall be deactivated, unless equipped with ground-fault circuit interrupters.

(ii) Glove bag systems, shall be used to remove PACM and/or ACM from straight runs of piping with the following specifications and work practices.

(A) Specifications:

(1) Glovebags shall be made of 6 mil thick plastic and shall be seamless at the bottom.

(2) [Reserved] (B) Work Practices:

(1) Each glovebag shall be installed so that it completely covers the circumference of pipe or other structure where the work is to be done.

(2) Glovebags shall be smoke-tested for leaks and any leaks sealed prior to use.

(3) Glovebags may be used only once and may not be moved.

(4) Glovebags shall not be used on surfaces whose temperature exceeds 150 deg..

(5) Prior to disposal, glovebags shall be collapsed by removing air within them using a HEPA vacuum.

(6) Before beginning the operation, loose and friable material adjacent to the glovebag/box operation shall be wrapped and sealed in two layers of six mil plastic or otherwise rendered intact.

(7) Where system uses attached waste bag, such bag shall be connected to collection bag using hose or other material which shall withstand pressure of ACM waste and water without losing its integrity:

(8) Sliding valve or other device shall separate waste bag from hose to ensure no exposure when waste bag is disconnected:

(9) At least two persons shall perform Class I glovebag removals.

(iii) Negative Pressure Glove Bag Systems. Negative pressure glove bag systems shall be used to remove ACM or PACM from piping.

(A) Specifications: In addition to specifications for glove bags systems above, negative pressure glove bag systems shall attach HEPA vacuum system or other device to bag to prevent collapse during removal.

(B) Work Practices:

(1) The employer shall comply with the work practices for glove bag systems in paragraph (g)(5)(ii)(B)(2) of this section,

(2) The HEPA vacuum cleaner or other device used to prevent collapse of bag during removal shall run continually during the operation.

(3) Where a separate waste bag is used along with a collection bag and discarded after one use, the collection bag may be reused if rinsed clean with amended water before reuse.

(iv) Negative Pressure Glove Box systems: Negative pressure glove boxes shall be used to remove ACM or PACM from pipe runs with the following specifications and work practices.

(A) Specifications:

(1) Glove boxes shall be constructed with rigid sides and made from metal or other material which can withstand the weight of the ACM and PACM and water used during removal:

(2) A negative pressure generator shall be used to create negative pressure in system:

(3) An air filtration unit shall be attached to the box:

(4) The box shall be fitted with gloved apertures:

(5) An aperture at the base of the box shall serve as a bagging outlet for waste ACM and water:

(6) A back-up generator shall be present on site:

(7) Waste bags shall consist of 6 mil thick plastic double-bagged before they are filled or plastic thicker than 6 mil.

(B) Work practices:

(1) At least two persons shall perform the removal:

(2) The box shall be smoke tested prior to each use:

(3) Loose or damaged ACM adjacent to the box shall be wrapped and sealed in two layers of 6 mil plastic prior to the job, or otherwise made intact prior to the job.

(4) A HEPA filtration system shall be used to maintain pressure barrier in box.

(v) Water Spray Process System: A water spray process system may be used for removal of ACM and PACM from cold line piping if, employees carrying out such process have completed a 40-hour separate training course in its use, in addition to training required for employees performing Class I work. The system shall meet the following specifications and shall be performed by employees using the following work practices.

(A) Specifications:

(1) Piping from which insulation will be removed shall be surrounded on 3 sides by rigid framing,

(2) A 360 degree water spray, delivered through nozzles supplied by a high pressure separate water line, shall be formed around the piping.

(3) The spray shall collide to form a fine aerosol which provides a liquid barrier between workers and the ACM and PACM.

(B) Work Practices:

(1) The system shall be run for at least 10 minutes before removal begins.

(2) All removal shall take place within the barrier.

(3) The system shall be operated by at least three persons, one of whom shall not perform removal but shall check equipment, and ensure proper operation of the system.

(4) After removal, the ACM and PACM shall be bagged while still inside the water barrier.

(vi) A small walk-in enclosure which accommodates no more than two persons (mini-enclosure) may be used if the disturbance or removal can be completely contained by the enclosure, with the following specifications and work practices.

(A) Specifications:

(1) The fabricated or job-made enclosure shall be constructed of 6 mil plastic or equivalent:

(2) The enclosure shall be placed under negative pressure by means of a HEPA filtered vacuum or similar ventilation unit:

(B) Work practices:

(1) Before use, the minienclosure shall be inspected for leaks and smoke tested to detect breaches, and breaches sealed.

(2) Before reuse, the interior shall be completely washed with amended water and HEPA-vacuumed.

(3) During use air movement shall be directed away from the employee's breathing zone within the minienclosure.

(6) Alternative control methods for Class I work. Class I work may be performed using a control method which is not referenced in paragraph (g)(5) of this section, or which modifies a control method referenced in paragraph (g)(5) of this section, if the following provisions are complied with:

(i) The control method shall enclose, contain or isolate the processes or source of airborne asbestos dust, or otherwise capture or redirect such dust before it enters the breathing zone of employees.

(ii) A certified industrial hygienist or licensed professional engineer who is also qualified as a project designer as defined in paragraph (b) of this section, shall evaluate the work area, the projected work practices and the engineering controls and shall certify in writing that: the planned control method is adequate to reduce direct and indirect employee exposure to below the PELs under worst- case conditions of use, and that the planned control method will prevent asbestos contamination outside the regulated area, as measured by clearance sampling which meets the requirements of EPA's Asbestos in Schools Rule issued under AHERA, or perimeter monitoring which meets the criteria in paragraph (g)(4)(i)(B)(2) of this section.

(A) Where the TSI or surfacing material to be removed is 25 linear or 10 square feet or less , the evaluation required in paragraph (g)(6) of this section may be performed by a "qualified person", and may omit consideration of perimeter or clearance monitoring otherwise required.

(B) The evaluation of employee exposure required in paragraph (g)(6) of this section, shall include and be based on sampling and analytical data representing employee exposure during the use of such method under worst-case conditions and by employees whose training and experience are equivalent to employees who are to perform the current job.

(iii) Before work which involves the removal of more than 25 linear or 10 square feet of TSI or surfacing ACM/PACM is begun using an alternative method which has been the subject of a paragraph (g)(6) required evaluation and certification, the employer shall send a copy of such evaluation and certification to the national office of OSHA, Office of Technical Supportm, Room N3653, 200 Constitution Avenue, NW, Washington, DC 20210.

(7) Work Practices and Engineering Controls for Class II work.

(i) All Class II work, shall be supervised by a qualified person as defined in paragraph (b) of this section.

(ii) For all indoor Class II jobs, where the employer has not produced a negative exposure assessment pursuant to paragraph (f)(4)(iii) of this section, or where during the job changed conditions indicate there may be exposure above the PEL or where the employer does not remove the ACM in a substantially intact state, the employer shall use one of the following methods to ensure that airborne asbestos does not migrate from the regulated area;

(A) Critical barriers shall be placed over all openings to the regulated area; or,

(B) The employer shall use another barrier or isolation method which prevents the migration of airborne asbestos from the regulated area, as verified by perimeter area monitoring or clearance monitoring which meets the criteria set out in paragraph (g)(4)(i)(B)(2) of this section.

(iii) Impermeable dropcloths shall be placed on surfaces beneath all removal activity;

(iv) All Class II asbestos work shall be performed using the work practices and requirements set out above in paragraph (g)(3)(i) through (v) of this section.

(8) Additional Controls for Class II work. Class II asbestos work shall also be performed by complying with the work practices and controls designated for each type of asbestos work to be performed, set out in this paragraph. Where more than one control method may be used for a type of asbestos work, the employer may choose one or a combination of designated control methods. Class II work also may be performed using a method allowed for Class I work, except that glove bags and glove boxes are allowed if they fully enclose the Class II material to be removed.

(i) For removing vinyl and asphalt flooring/deck materials which contain ACM or for which in buildings constructed not later than 1980, the employer has not verified the absence of ACM pursuant to paragraph (g)(8)(i)(I): the employer shall ensure that employees comply with the following work practices and that employees are trained in these practices pursuant to paragraph (k)(8) of this section:

(A) Flooring/deck materials or its backing shall not be sanded.

(B) Vacuums equipped with HEPA filter, disposable dust bag, and metal floor tool (no brush) shall be used to clean floors.

(C) Resilient sheeting shall be removed by cutting with wetting of the snip point and wetting during delamination. Rip-up of resilient sheet floor material is prohibited.

(D) All scraping of residual adhesive and/or backing shall be performed using wet methods.

(E) Dry sweeping is prohibited.

(F) Mechanical chipping is prohibited unless performed in a negative pressure enclosure which meets the requirements of paragraph (g)(5)(iv) of this section.

(G) Tiles shall be removed intact, unless the employer demonstrates that intact removal is not possible.

(H) When tiles are heated and can be removed intact, wetting may be omitted.

(I) Resilient flooring/deck material in buildings/vessels constructed no later than 1980, including associated mastic and backing shall be assumed to be asbestos-containing unless an industrial hygienist determines that it is asbestos-free using recognized analytical techniques.

(ii) For removing roofing material which contains ACM the employer shall ensure that the following work practices are followed:

(A) Roofing material shall be removed in an intact state to the extent feasible.

(B) Wet methods shall be used where feasible.

(C) Cutting machines shall be continuously misted during use, unless a competent person determines that misting substantially decreases worker safety.

(D) All loose dust left by the sawing operation must be HEPA vacuumed immediately.

(E) Unwrapped or unbagged roofing material shall be immediately lowered to the ground via covered, dust-tight chute, crane or hoist, or placed in an impermeable waste bag or wrapped in plastic sheeting and lowered to ground no later than the end of the work shift.

(F) Upon being lowered, unwrapped material shall be transferred to a closed receptacle in such manner so as to preclude the dispersion of dust.

(G) Roof level heating and ventilation air intake sources shall be isolated or the ventilation system shall be shut down.

(iii) When removing cementitious asbestos-containing siding, shingles (CACS), or transite panels containing ACM, the employer shall ensure that the following work practices are followed:

(A) Cutting, abrading or breaking siding, shingles, or transite panels shall be prohibited unless the employer can demonstrate that methods less likely to result in asbestos fiber release cannot be used.

(B) Each panel or shingle shall be sprayed with amended water prior to removal.

(C) Unwrapped or unbagged panels or shingles shall be immediately lowered to the ground via covered dust-tight chute, crane or hoist, or placed in an impervious waste bag or wrapped in plastic sheeting and lowered to the ground no later than the end of the work shift.

(D) Nails shall be cut with flat, sharp instruments.

(iv) When removing gaskets containing ACM, the employer shall ensure that the following work practices are followed:

(A) If a gasket is visibly deteriorated and unlikely to be removed intact, removal shall be undertaken within a glovebag as described in paragraph (g)(5)(ii) of this section.

(B) The gasket shall be thoroughly wetted with amended water prior to its removal.

(C) The wet gasket shall be immediately placed in a disposal container.

(D) Any scraping to remove residue must be performed wet.

(v) When performing any other Class II removal of asbestos containing material for which specific controls have not been listed in paragraph (g)(8)(iv)(A) through (D) of this section, the employer shall ensure that the following work practices are complied with.

(A) The material shall be thoroughly wetted with amended water prior and during its removal.

(B) The material shall be removed in an intact state unless the employer demonstrates that intact removal is not possible.

(C) Cutting, abrading or breaking the material shall be prohibited unless the employer can demonstrate that methods less likely to result in asbestos fiber release are not feasible.

(D) Asbestos-containing material removed, shall be immediately bagged or wrapped, or kept wetted until transferred to a closed receptacle, no later than the end of the work shift.

(vi) Alternative Work Practices and Controls. Instead of the work practices and controls listed in paragraphs (g)(8)(i) through (v) of this section, the employer may use different or modified engineering and work practice controls if the following provisions are complied with.

(A) The employer shall demonstrate by data representing employee exposure during the use of such method under conditions which closely resemble the conditions under which the method is to be used, that employee exposure will not exceed the PELs under any anticipated circumstances.

(B) A qualified person shall evaluate the work area, the projected work practices and the engineering controls, and shall certify in writing, that the different or modified controls are adequate to reduce direct and indirect employee exposure to below the PELs under all expected conditions of use and that the method meets the requirements of this standard. The evaluation shall include and be based on data representing employee exposure during the use of such method under conditions which closely resemble the conditions under which the method is to be used for the current job, and by employees whose training and experience are equivalent to employees who are to perform the current job.

(9) Work Practices and Engineering Controls for Class III asbestos work. Class III asbestos work shall be conducted using engineering and work practice controls which minimize the exposure to employees performing the asbestos work and to bystander employees.

(i) The work shall be performed using wet methods.

(ii) To the extent feasible, the work shall be performed using local exhaust ventilation.

(iii) Where the disturbance involves drilling, cutting, abrading, sanding, chipping, breaking, or sawing of thermal system insulation or surfacing material, the employer shall use impermeable dropcloths and shall isolate the operation using mini-enclosures or glove bag systems pursuant to paragraph (g)(5) of this section.

(iv) Where the employer does not demonstrate by a negative exposure assessment performed in compliance with paragraph (f)(4)(iii) of this section that the PELs will not be exceeded, or where monitoring results show exceedances of a PEL, the employer shall contain the area using impermeable dropcloths and plastic barriers or their equivalent, or shall isolate the operation using mini-enclosure or glove bag systems pursuant to paragraph (g)(5) of this section.

(v) Employees performing Class III jobs which involve the disturbance of TSI or surfacing ACM or PACM or where the employer does not demonstrate by a "negative exposure assessment" in compliance with paragraph (e)(4)(iii) of this section that the PELs will not be exceeded or where monitoring results show exceedances of the PEL, shall wear respirators which are selected, used and fitted pursuant to provisions of paragraph (h) of this section.

(10) Class IV asbestos work. Class IV asbestos jobs shall be conducted by employees trained pursuant to the asbestos awareness training program set out in paragraph (k)(8) of this section. In addition, all Class IV jobs shall be conducted in conformity with the requirements set out in paragraph (g)(1) of this section, mandating wet methods, HEPA vacuums, and prompt clean up of debris containing ACM or PACM.

(i) Employees cleaning up debris and waste in a regulated area where respirators are required shall wear respirators which are selected, used and fitted pursuant to provisions of paragraph (h) of this section.

(ii) Employers of employees cleaning up waste and debris in an area where friable TSI or surfacing ACM/PACM is accessible, shall assume that such waste and debris contain asbestos.

(11) Specific compliance methods for brake and clutch repair: (i) Engineering controls and work practices for brake and clutch repair and service. During automotive brake and clutch inspection, disassembly, repair and assembly operations, the employer shall institute engineering controls and work practices to reduce employee exposure to materials containing asbestos using a negative pressure enclosure/HEPA vacuum system method or low pressure/wet cleaning method, which meets the detailed requirements set out in Appendix L to this section. The employer may also comply using an equivalent method which follows written procedures which the employer demonstrates can achieve results equivalent to Method A. For facilities in which no more than 5 pair of brakes or 5 clutches are inspected, disassembled, repaired, or assembled per week, the method set for in paragraph [D] of Appendix L to this section may be used.

(ii) The employer may also comply by using an equivalent method which follows written procedures, which the employer demonstrates can achieve equivalent exposure reductions as do the two "preferred methods." Such demonstration must include monitoring data conducted under workplace conditions closely resembling the process, type of asbestos containing materials, control method, work practices and environmental conditions which the equivalent method will be used, or objective data, which document that under all reasonably foreseeable conditions of brake and clutch repair applications, the method results in exposures which are equivalent to the methods set out in Appendix L.

(h) Respiratory protection (1) General. The employer shall provide respirators, and ensure that they are used, where required by this section. Respirators shall be used in the following circumstances:

(i) During all Class I asbestos jobs.

(ii) During all Class II work where the ACM is not removed in a substantially intact state.

(iii) During all Class II and III work which is not performed using wet methods.

(iv) During all Class II and III asbestos jobs where the employer does not produce a "negative exposure assessment".

(v) During all Class III jobs where TSI or surfacing ACM or PACM is being disturbed.

(vi) During all Class IV work performed within regulated areas where employees performing other work are required to wear respirators.

(vii) During all work covered by this section where employees are exposed above the TWA or excursion limit.

(viii) In emergencies.

(2) Respirator selection.

(i) Where respirators are used, the employer shall select and provide, at no cost to the employee, the appropriate respirator as specified in Table 1, and shall ensure that the employee uses the respirator provided.

(ii) The employer shall select respirators from among those jointly approved as being acceptable for protection by the Mine Safety and Health Administration (MSHA) and the National Institute for Occupational Safety and Health (NIOSH) under the provisions of 30 CFR Part 11.

(iii) The employer shall provide a tight fitting powered, air-purifying respirator in lieu of any negative-pressure respirator specified in Table 1 whenever:

(A) An employee performing Class I, II or III work chooses to use this type of respirator; and

(B) This respirator will provide adequate protection to the employee.

Table 1. -- Respiratory Protection for Asbestos Fibers
Airborne concentration of asbestos or conditions of use Required respirator
Not in excess of 1 f/cc
  • (10) X PEL), or otherwise as required independent of exposure pursuant to (h)(2)(iv)
Half-mask air purifying respirator other than a disposable respirator, equipped with high efficiency filters
Not in excess of 5 f/cc (50 X PEL) Full facepiece air-purifying respirator equipped with high efficiency filters
Not in excess of 10 f/cc (100 X PEL) Any powered air-purifying respirator equipped with high efficiency filters or any supplied air respirator operated in continuous flow mode
Not in excess of 100 f/cc (1,000 X PEL) Full facepiece supplied air respirator operated in pressure demand mode
Greater than 100 f/cc (1,000 X PEL) or unknown concentration Full facepiece supplied air respirator operated in pressure demand mode, equipped with an auxiliary positive pressure self-contained breathing apparatus
Note:a. Respirators assigned for high environmental concentrations may be used at lower concentrations, or when required respirator use is independent of concentration
b. A high efficiency filter means a filter that is at least 99.97 percent efficient against mono-dispersed particles of 0.3 micrometers in diameter or larger

(iv) In addition to the above selection criterion, the employer shall provide a half-mask air purifying respirator, other than a disposable respirator, equipped with high efficiency filters whenever the employee performs the following activities: Class II and III asbestos jobs where the employer does not produce a negative exposure assessment; and Class III jobs where TSI or surfacing ACM or PACM is being disturbed.

(v) In addition to the above selection criteria, the employer shall provide a full facepiece supplied air respirator operated in the pressure demand mode equipped with an auxiliar76y positive pressure self-contained breathing apparatus for all employees within the regulated area where Class I work is being performed for which a negative exposure assessment has not been produced.

(3) Respirator program. (i) Where respiratory protection is used, the employer shall institute a respirator program in accordance with 29 CFR 1910.134(b), (d), (e), and (f).

(ii) The employer shall permit each employee who uses a filter respirator to change the filter elements whenever an increase in breathing resistance is detected and shall maintain an adequate supply of filter elements for this purpose.

(iii) Employees who wear respirators shall be permitted to leave work areas to wash their faces and respirator facepieces whenever necessary to prevent skin irritation associated with respirator use.

(iv) No employee shall be assigned to tasks requiring the use of respirators if, based on his or her most recent examination, an examining physician determines that the employee will be unable to function normally wearing a respirator, or that the safety or health of the employee or of other employees will be impaired by the use of a respirator. Such employee shall be assigned to another job or given the opportunity to transfer to a different position the duties of which he or she is able to perform with the same employer, in the same geographical area, and with the same seniority, status, and rate of pay and other job benefits he or she had just prior to such transfer, if such a different position is available.

(4) Respirator fit testing. (i) The employer shall ensure that the respirator issued to the employee exhibits the least possible facepiece leakage and that the respirator is fitted properly.

(ii) Employers shall perform either quantitative or qualitative face fit tests at the time of initial fitting and at least every 6 months thereafter for each employee wearing a negative-pressure respirator. The qualitative fit tests may be used only for testing the fit of half-mask respirators where they are permitted to be worn, or of full-facepiece air purifying respirators where they are worn at levels at which half-facepiece air purifying respirators are permitted. Qualitative and quantitative fit tests shall be conducted in accordance with Appendix C of this section. The tests shall be used to select facepieces that provide the required protection as prescribed in Table 1, in paragraph (h)(2)(iii) of this section.

(i) Protective clothing (1) General. The employer shall provide and require the use of protective clothing, such as coveralls or similar whole-body clothing, head coverings, gloves, and foot coverings for any employee exposed to airborne concentrations of asbestos that exceed the TWA and/or excursion limit prescribed in paragraph (c) of this section, or for which a required negative exposure assessment is not produced, and for any employee performing Class I operations which involve the removal of over 25 linear or 10 square feet of TSI or surfacing ACM or PACM.

(2) Laundering. (i) The employer shall ensure that laundering of contaminated clothing is done so as to prevent the release of airborne asbestos in excess of the TWA or excursion limit prescribed in paragraph (c) of this section.

(ii) Any employer who gives contaminated clothing to another person for laundering shall inform such person of the requirement in paragraph (i)(2)(i) of this section to effectively prevent the release of airborne asbestos in excess of the TWA excursion limit prescribed in paragraph (c) of this section.

(3) Contaminated clothing. Contaminated clothing shall be transported in sealed impermeable bags, or other closed, impermeable containers, and be labeled in accordance with paragraph (k) of this section.

(4) Inspection of protective clothing. (i) The qualified person shall examine worksuits worn by employees at least once per workshift for rips or tears that may occur during performance of work.

(ii) When rips or tears are detected while an employee is working, rips and tears shall be immediately mended, or the worksuit shall be immediately replaced.

(j) Hygiene facilities and practices for employees. (1) Requirements for employees performing Class I asbestos jobs.

(i) Decontamination areas: For all Class I jobs involving over 25 linear or 10 square feet of TSI or surfacing ACM or PACM, the employer shall establish a decontamination area that is adjacent and connected to the regulated area for the decontamination of such employees. The decontamination area shall consist of an equipment room, shower area, and clean room in series. The employer shall ensure that employees enter and exit the regulated area through the decontamination area.

(A) Equipment room. The equipment room shall be supplied with impermeable, labeled bags and containers for the containment and disposal of contaminated protective equipment.

(B) Shower area. Shower facilities shall be provided which comply with 29 CFR 1910.141(d)(3), unless the employer can demonstrate that they are not feasible. The showers shall be adjacent both to the equipment room and the clean room, unless the employer can demonstrate that this location is not feasible. Where the employer can demonstrate that it is not feasible to locate the shower between the equipment room and the clean room, or where the work is performed outdoors, or when the work involving asbestos exposure takes place on board a ship, the employers shall ensure that employees:

(1) Remove asbestos contamination from their worksuits in the equipment room using a HEPA vacuum before proceeding to a shower that is not adjacent to the work area; or (2) Remove their contaminated worksuits in the equipment room, then don clean worksuits, and proceed to a shower that is not adjacent to the work area.

(C) Clean change room. The clean room shall be equipped with a locker or appropriate storage container for each employee's use. When the employer can demonstrate that it is not feasible to provide a clean change area adjacent to the work area, or where the work is performed outdoors, or when the work takes place aboard a ship, the employer may permit employees engaged in Class I asbestos jobs to clean their protective clothing with a portable HEPA-equipped vacuum before such employees leave the regulated area. Such employees however must then change into street clothing in clean change areas provided by the employer which otherwise meet the requirements of this section.

(ii) Decontamination area entry procedures. The employer shall ensure that employees:

(A) Enter the decontamination area through the clean room;

(B) Remove and deposit street clothing within a locker provided for their use; and

(C) Put on protective clothing and respiratory protection before leaving the clean room.

(D) Before entering the regulated area, the employer shall ensure that employees pass through the equipment room.

(iii) Decontamination area exit procedures. The employer shall ensure that:

(A) Before leaving the regulated area, employees shall remove all gross contamination and debris from their protective clothing.

(B) Employees shall remove their protective clothing in the equipment room and deposit the clothing in labeled impermeable bags or containers.

(C) Employees shall not remove their respirators in the equipment room.

(D) Employees shall shower prior to entering the clean room.

(E) After showering, employees shall enter the clean room before changing into street clothes.

(iv) Lunch Areas. Whenever food or beverages are consumed at the worksite where employees are performing Class I asbestos work, the employer shall provide lunch areas in which the airborne concentrations of asbestos are below the permissible exposure limit and/or excursion limit.

(2) Requirements for Class I work involving less than 25 linear or 10 square feet of TSI or surfacing and PACM, and for Class II and Class III asbestos work operations where exposures exceed a PEL or where there is no negative exposure assessment produced before the operation.

(i) The employer shall establish an equipment room or area that is adjacent to the regulated area for the decontamination of employees and their equipment which is contaminated with asbestos which shall consist of an area covered by a impermeable drop cloth on the floor/deck or horizontal working surface.

(ii) The area must be of sufficient size as to accommodate cleaning of equipment and removing personal protective equipment without spreading contamination beyond the area (as determined by visible accumulations).

(iii) Workclothing must be cleaned with a HEPA vacuum before it is removed.

(iv) All equipment and surfaces of containers filled with ACM must be cleaned prior to removing them from the equipment room or area.

(v) The employer shall ensure that employees enter and exit the regulated area through the equipment room or area.

(3) Requirements for Class IV work. Employers shall ensure that employees performing Class IV work within a regulated area comply with the hygiene practice required of employees performing work which has a higher classification within that regulated area. Otherwise employers of employees cleaning up debris and material which is TSI or surfacing ACM or identified as PACM shall provide decontamination facilities for such employees which are required by paragraph (j)(2) of this section.

(4) Smoking in work areas. The employer shall ensure that employees do not smoke in work areas where they are occupationally exposed to asbestos because of activities in that work area.

(k) Communication of hazards.

Note: This section applies to the communication of information concerning asbestos hazards in shipyard employment activities to facilitate compliance with this standard. Most asbestos-related shipyard activities involve previously installed building materials. Building/vessel owners often are the only and/or best sources of information concerning them. Therefore, they, along with employers of potentially exposed employees, are assigned specific information conveying and retention duties under this section. Installed Asbestos Containing Building/Vessel Material: Employers and building/vessel owners are required to treat TSI and sprayed or troweled on surfacing materials as asbestos-containing unless the employer, by complying with paragraph (k)(4) of this section determines that the material is not asbestos-containing. Asphalt or vinyl flooring/decking material installed in buildings or vessels no later than 1980 must also be considered as asbestos containing unless the employer/owner, pursuant to paragraph (g), of this section determines it is not asbestos containing. If the employer or building/vessel owner has actual knowledge or should have known, through the exercise of due diligence, that materials other than TSI and sprayed-on or troweled-on surfacing materials are asbestos-containing, they must be treated as such. When communicating information to employees pursuant to this standard, owners and employers shall identify "PACM" as ACM. Additional requirements relating to communication of asbestos work on multi-employer worksites are set out in paragraph (d) of this standard.

(1) Duties of building/vessel and facility owners. (i) Before work subject to this standard is begun, building/vessel and facility owners shall identify the presence, location and quantity of ACM, and/or PACM at the work site. All thermal system insulation and sprayed on or troweled on surfacing materials in buildings/vessels or substrates constructed no later than 1980 shall be identified as PACM. In addition, resilient flooring/decking material installed no later than 1980 shall also be identified as asbestos-containing.

(ii) Building/vessel and/or facility owners shall notify the following persons of the presence, location and quantity of ACM or PACM, at work sites in their buildings/facilities/vessels. Notification either shall be in writing or shall consist of a personal communication between the owner and the person to whom notification must be given or their authorized representatives:

(A) Prospective employers applying or bidding for work whose employees reasonably can be expected to work in or adjacent to areas containing such material;

(B) Employees of the owner who will work in or adjacent to areas containing such material:

(C) On multi-employer worksites, all employers of employees who will be performing work within or adjacent to areas containing such materials;

(D) Tenants who will occupy areas containing such materials.

(2) Duties of employers whose employees perform work subject to this standard in or adjacent to areas containing ACM and PACM. Building/vessel and facility owners whose employees perform such work shall comply with these provisions to the extent applicable.

(i) Before work in areas containing ACM and PACM is begun, employers shall identify the presence, location, and quantity of ACM, and/or PACM therein.

(ii) Before work under this standard is performed employers of employees who will perform such work shall inform the following persons of the location and quantity of ACM and/or PACM present at the work site and the precautions to be taken to insure that airborne asbestos is confined to the area.

(A) Owners of the building/vessel or facility;

(B) Employees who will perform such work and employers of employees who work and/or will be working in adjacent areas;

(iii) Within 10 days of the completion of such work, the employer whose employees have performed work subject to this standard, shall inform the building/vessel or facility owner and employers of employees who will be working in the area of the current location and quantity of PACM and/or ACM remaining in the former regulated area and final monitoring results, if any.

(3) In addition to the above requirements, all employers who discover ACM and/or PACM on a work site shall convey information concerning the presence, location and quantity of such newly discovered ACM and/or PACM to the owner and to other employers of employees working at the work site, within 24 hours of the discovery.

(4) Criteria to rebut the designation of installed material as PACM. (i) At any time, an employer and/or building/vessel owner may demonstrate, for purposes of this standard, that PACM does not contain asbestos. Building/vessel owners and/or employers are not required to communicate information about the presence of building material for which such a demonstration pursuant to the requirements of paragraph (k)(4)(ii) of this section has been made. However, in all such cases, the information, data and analysis supporting the determination that PACM does not contain asbestos, shall be retained pursuant to paragraph (n) of this section.

(ii) An employer or owner may demonstrate that PACM does not contain asbestos by the following:

(A) Having a completed inspection conducted pursuant to the requirements of AHERA (40 CFR Part 763, Subpart E) which demonstrates that the material is not ACM;

(B) Performing tests of the material containing PACM which demonstrate that no asbestos is present in the material. Such tests shall include analysis of 3 bulk samples of each homogeneous area of PACM collected in a randomly distributed manner. The tests, evaluation and sample collection shall be conducted by an accredited inspector or by a CIH. Analysis of samples shall be performed by persons or laboratories with proficiency demonstrated by current successful participation in a nationally recognized testing program such as the National Voluntary Laboratory Accreditation Program (NVLAP) of the National Institute for Standards and Technology (NIST) of the Round Robin for bulk samples administered by the American Industrial Hygiene Association (AIHA), or an equivalent nationally-recognized round robin testing program..

(5) At the entrance to mechanical rooms/areas in which employees reasonably can be expected to enter and which contain TSI or surfacing ACM and PACM, the building/vessel owner shall post signs which identify the material which is present, its location, and appropriate work practices which, if followed, will ensure that ACM and/or PACM will not be disturbed.

(6) Signs. (i) Warning signs that demarcate the regulated area shall be provided and displayed at each location where a regulated area is required to be established by paragraph (e) of this section. Signs shall be posted at such a distance from such a location that an employee may read the signs and take necessary protective steps before entering the area marked by the signs.

(ii) The warning signs required by (k)(6) of this section shall bear the following information.

DANGER

ASBESTOS

CANCER AND LUNG DISEASE HAZARD

AUTHORIZED PERSONNEL ONLY

RESPIRATORS AND PROTECTION CLOTHING ARE REQUIRED IN THIS AREA

(7) Labels. (i) Labels shall be affixed to all products containing asbestos and to all containers containing such products, including waste containers. Where feasible, installed asbestos products shall contain a visible label.

(ii) Labels shall be printed in large, bold letters on a contrasting background.

(iii) Labels shall be used in accordance with the requirements of 29 CFR 1910.1200(f) of OSHA's Hazard Communication standard, and shall contain the following information:

DANGER

CONTAINS ASBESTOS FIBERS

AVOID CREATING DUST

CANCER AND LUNG DISEASE HAZARD

(iv) [Reserved]

(v) Labels shall contain a warning statement against breathing asbestos fibers.

(vi) The provisions for labels required by paragraphs (k)(2)(i) through (k)(2)(iii) of this section do not apply where:

(A) Asbestos fibers have been modified by a bonding agent, coating, binder, or other material, provided that the manufacturer can demonstrate that, during any reasonably foreseeable use, handling, storage, disposal, processing, or transportation, no airborne concentrations of asbestos fibers in excess of the permissible exposure limit and/or excursion limit will be released, or (B) Asbestos is present in a product in concentrations less than 1.0 percent by weight.

(vii) When a building/vessel owner/or employer identifies previously installed PACM and/or ACM, labels or signs shall be affixed or posted so that employees will be notified of what materials contain PACM and/or ACM. The employer shall attach such labels in areas where they will clearly be noticed by employees who are likely to be exposed, such as at the entrance to mechanical rooms/areas. Signs required by paragraph (k)(5) of this section may be posted in lieu of labels so long as they contain information required for labelling.

(8) Employee information and training. (i) The employer shall, at no cost to the employee,institute a training program for all employees who install asbestos containing products and for all employees who perform Class I through IV asbestos operations, and shall ensure their participation in the program.

(ii) Training shall be provided prior to or at the time of initial assignment and at least annually thereafter.

(iii) Training for Class I and II operations shall be the equivalent in curriculum, training method and length to the EPA Model Accreditation Plan (MAP) asbestos abatement worker training (40 CFR Pt. 763, Subpt. E, App. C). For employers whose Class II work with asbestos-containing material involves only the removal and/or disturbance of one generic category of building/vessel material, such as roofing materials, flooring/deck materials, siding materials or transite panels, instead, such employer is required to train employees who perform such work by providing a training course which includes as a minimum all the elements included in paragraph (k)(8)(v) of this section and in addition, the specific work practices and engineering controls set forth in paragraph (g) of this section which specifically relate to that material category. Such course shall include "hands-on" training and shall take at least 8 hours.

(iv) Training for Class III employees shall be the equivalent in curriculum and training method to the 16-hour Operations and Maintenance course developed by EPA for maintenance and custodial workers who conduct activities that will result in the disturbance of ACM. [See 40 CFR 763.92(a)(2)]. Such course shall include "hands-on" training in the use of respiratory protection and work practices and shall take at least 16 hours.

(v) Training for employees performing Class IV operations shall be the equivalent in curriculum and training method to the awareness training course developed by EPA for maintenance and custodial workers who work in buildings containing asbestos- containing material. (See 40 CFR 763.92 (a)(1)). Such course shall include available information concerning the locations of PACM and ACM, and asbestos-containing flooring material, or flooring material where the absence of asbestos has not been certified; and instruction in recognition of damage, deterioration, and delamination of asbestos containing building materials. Such course shall take at least 2 hours.

(vi) The training program shall be conducted in a manner that the employee is able to understand. In addition to the content required by provisions in paragraph (k)(8)(iii) of this section, the employer shall ensure that each such employee is informed of the following:

(A) Methods of recognizing asbestos, including the requirement in paragraph (k)(1) of this section to presume that certain building materials contain asbestos.;

(B) The health effects associated with asbestos exposure;

(C) The relationship between smoking and asbestos in producing lung cancer;

(D) The nature of operations that could result in exposure to asbestos, the importance of necessary protective controls to minimize exposure including, as applicable, engineering controls, work practices, respirators, housekeeping procedures, hygiene facilities, protective clothing, decontamination procedures, emergency procedures, and waste disposal procedures, and any necessary instruction in the use of these controls and procedures; where Class II and IV work will be or is performed, the contents of EPA 20T-2003, "Managing Asbestos In- Place" July 1990 or its equivalent in content;

(E) The purpose, proper use, fitting instructions, and limitations of respirators as required by 29 CFR 1910.134;

(F) The appropriate work practices for performing the asbestos job;

(G) Medical surveillance program requirements; and

(H) The content of this standard, including appendices.

(I) The names, addresses and phone numbers of public health organizations which provide information, materials and/or conduct programs concerning smoking cessation. The employer may distribute the list of such organizations contained in Appendix J, to comply with this requirement.

(J) The requirements for posting signs and affixing labels and the meaning of the required legends for such signs and labels.

(9) Access to training materials. (i) The employer shall make readily available to affected employees without cost written materials relating to the employee training program, including a copy of this regulation.

(ii) The employer shall provide to the Assistant Secretary and the Director, upon request, all information and training materials relating to the employee information and training program.

(iii) The employer shall inform all employees concerning the availability of self-help smoking cessation program material. Upon employee request, the employer shall distribute such material, consisting of NIH Publication No, 89-1647, or equivalent self-help material, which is approved or published by a public health organization listed in Appendix J.

(1) Housekeeping -- (1) Vacuuming. Where vacuuming methods are selected, HEPA filtered vacuuming equipment must be used. The equipment shall be used and emptied in a manner that minimizes the reentry of asbestos into the workplace.

(2) Waste disposal. Asbestos waste, scrap, debris, bags, containers, equipment, and contaminated clothing consigned for disposal shall be collected and disposed of in sealed, labeled, impermeable bags or other closed, labeled, impermeable containers.

(3) Care of asbestos-containing flooring/deck material. (i) All vinyl and asphalt flooring/deck material shall be maintained in accordance with this paragraph unless the building/facility owner demonstrates, pursuant to paragraph (g) that the flooring/deck does not contain asbestos.

(i) Sanding of flooring/deck material is prohibited.

(ii) Stripping of finishes shall be conducted using low abrasion pads at speed lower than 300 rpm and wet methods.

(iii) Burnishing or dry buffing may be performed only on flooring/ deck which has sufficient finish so that the pad cannot contact the flooring/deck material.

(4) Dust and debris in an area containing accessible thermal system insulation or surfacing material or visibly deteriorated ACM. (i) shall not be dusted or swept dry, or vacuumed without using a HEPA filter;

(ii) shall be promptly cleaned up and disposed in leak tight containers.

(m) Medical surveillance -- (1) General -- (i) Employees covered. The employer shall institute a medical surveillance program for all employees who for a combined total of 30 or more days per year are engaged in Class I, II, and III work or are exposed at or above the permissible exposure limit or excursion limit, and for employees who wear negative pressure respirators pursuant to the requirements of this section.

(ii) Examination by a physician.

(A) The employer shall ensure that all medical examinations and procedures are performed by or under the supervision of a licensed physician, and are provided at no cost to the employee and at a reasonable time and place.

(B) Persons other than such licensed physicians who administer the pulmonary function testing required by this section shall complete a training course in spirometry sponsored by an appropriate academic or professional institution.

(2) Medical examinations and consultations -- (i) Frequency. The employer shall make available medical examinations and consultations to each employee covered under paragraph (m)(1)(i) of this section on the following schedules:

(A) Prior to assignment of the employee to an area where negative- pressure respirators are worn;

(B) When the employee is assigned to an area where exposure to asbestos may be at or above the permissible exposure for 30 or more days per year, a medical examination must be given within 10 working days following the thirtieth day of exposure;

(C) And at least annually thereafter.

(D) If the examining physician determines that any of the examinations should be provided more frequently than specified, the employer shall provide such examinations to affected employees at the frequencies specified by the physician.

(E) Exception: No medical examination is required of any employee if adequate records show that the employee has been examined in accordance with this paragraph within the past 1-year period.

(ii) Content. Medical examinations made available pursuant to paragraphs (m)(2)(i)(A) through (m)(2)(i)(C) of this section shall include:

(A) A medical and work history with special emphasis directed to the pulmonary, cardiovascular, and gastrointestinal systems.

(B) On initial examination, the standardized questionnaire contained in Part 1 of Appendix D to this section and, on annual examination, the abbreviated standardized questionnaire contained in Part 2 of Appendix D to this section.

(C) A physical examination directed to the pulmonary and gastrointestinal systems, including a chest ,x-ray to be administered at the discretion of the physician, and pulmonary function tests of forced vital capacity (FVC) and forced expiratory volume at one second (FEV(1)). Interpretation and classification of chest roentgenogram shall be conducted in accordance with Appendix E to this section.

(D) Any other examinations or tests deemed necessary by the examining physician.

(3) Information provided to the physician. The employer shall provide the following information to the examining physician:

(i) A copy of this standard and Appendices D, E, G, and I to this section;

(ii) A description of the affected employee's duties as they relate to the employee's exposure;

(iii) The employee's representative exposure level or anticipated exposure level;

(iv) A description of any personal protective and respiratory equipment used or to be used; and

(v) Information from previous medical examinations of the affected employee that is not otherwise available to the examining physician.

(4) Physician's written opinion. (i) The employer shall obtain a written opinion from the examining physician. This written opinion shall contain the results of the medical examination and shall include:

(A) The physician's opinion as to whether the employee has any detected medical conditions that would place the employee at an increased risk of material health impairment from exposure to asbestos;

(B) Any recommended limitations on the employee or on the use of personal protective equipment such as respirators; and

(C) A statement that the employee has been informed by the physician of the results of the medical examination and of any medical conditions that may result from asbestos exposure.

(D) A statement that the employee has been informed by the physician of the increased risk of lung cancer attributable to the combined effect of smoking and asbestos exposure.

(ii) The employer shall instruct the physician not to reveal in the written opinion given to the employer specific findings or diagnoses unrelated to occupational exposure to asbestos.

(iii) The employer shall provide a copy of the physician's written opinion to the affected employee within 30 days from its receipt.

(n) Recordkeeping -- (1) Objective data relied on pursuant to paragraph (f) of this section.

(i) Where the employer has relied on objective data that demonstrate that products made from or containing asbestos are not capable of releasing fibers of asbestos in concentrations at or above the permissible exposure limit and/or excursion limit under the expected conditions of processing, use, or handling to satisfy the requirements of paragraph (f) of this section, the employer shall establish and maintain an accurate record of objective data reasonably relied upon in support of the exemption.

(ii) The record shall include at least the following information:

(A) The product qualifying for exemption;

(B) The source of the objective data;

(C) The testing protocol, results of testing, and/or analysis of the material for the release of asbestos;

(D) A description of the operation exempted and how the data support the exemption; and

(E) Other data relevant to the operations, materials, processing, or employee exposures covered by the exemption.

(iii) The employer shall maintain this record for the duration of the employer's reliance upon such objective data.

(2) Exposure measurements. (i) The employer shall keep an accurate record of all measurements taken to monitor employee exposure to asbestos as prescribed in paragraph (f) of this section. Note: The employer may utilize the services of qualified organizations such as industry trade associations and employee associations to maintain the records required by this section.

(ii) This record shall include at least the following information:

(A) The date of measurement;

(B) The operation involving exposure to asbestos that is being monitored;

(C) Sampling and analytical methods used and evidence of their accuracy;

(D) Number, duration, and results of samples taken;

(E) Type of protective devices worn, if any; and

(F) Name, social security number, and exposure of the employees whose exposures are represented.

(iii) The employer shall maintain this record for at least thirty (30) years, in accordance with 29 CFR 1910.20.

(3) Medical surveillance. (i) The employer shall establish and maintain an accurate record for each employee subject to medical surveillance by paragraph (m) of this section, in accordance with 29 CFR 1910.20.

(ii) The record shall include at least the following information:

(A) The name and social security number of the employee;

(B) A copy of the employee's medical examination results, including the medical history, questionnaire responses, results of any tests, and physician's recommendations.

(C) Physician's written opinions;

(D) Any employee medical complaints related to exposure to asbestos; and

(E) A copy of the information provided to the physician as required by paragraph (m) of this section.

(iii) The employer shall ensure that this record is maintained for the duration of employment plus thirty (30) years, in accordance with 29 CFR 1910.20.

(4) Training records. The employer shall maintain all employee training records for one 1 year beyond the last date of employment by that employer.

(5) Data to Rebut PACM:

(i) Where the building owner and employer have relied on data to demonstrate that PACM is not asbestos-containing, such data shall be maintained for as long as they are relied upon to rebut the presumption.

(ii) [Reserved]

(6) Records of Required Notification. (i) Where the building/vessel owner has communicated and received information concerning the identity, location and quantity of ACM and PACM, written records of such notifications and their content shall be maintained by the owner for the duration of ownership and shall be transferred to successive owners of such buildings/facilities/vessels.

(ii) [Reserved]

(7) Availability. (i) The employer, upon written request, shall make all records required to be maintained by this section available to the Assistant Secretary and the Director for examination and copying.

(ii) The employer, upon request, shall make any exposure records required by paragraphs (f) and (n) of this section available for examination and copying to affected employees, former employees, designated representatives, and the Assistant Secretary, in accordance with 29 CFR 1910.20(a) through (e) and (g) through (i).

(iii) The employer, upon request, shall make employee medical records required by paragraphs (m) and (n) of this section available for examination and copying to the subject employee, anyone having the specific written consent of the subject employee, and the Assistant Secretary, in accordance with 29 CFR 1910.20.

(8) Transfer of records. (i) The employer shall comply with the requirements concerning transfer of records set forth in 29 CFR 1910.20 (h).

(ii) Whenever the employer ceases to do business and there is no successor employer to receive and retain the records for the prescribed period, the employer shall notify the Director at least 90 days prior to disposal and, upon request, transmit them to the Director.

(o) Qualified person. (1) General. On all shipyard worksites covered by this standard, the employer shall designate a qualified person, having the qualifications and authorities for ensuring worker safety and health required by Subpart C, General Safety and Health Provisions for Construction (29 CFR 1926.20 through 1926.32).

(2) Required Inspections by the Qualified Person. Sec. 1926.20(b)(2) which requires health and safety prevention programs to provide for frequent and regular inspections of the job sites, materials, and equipment to be made by qualified persons, is incorporated.

(3) Additional Inspections. In addition, the qualified person shall make frequent and regular inspections of the job sites, in order to perform the duties set out in paragraph (p)(3)(i) and (ii) of this section. For Class I jobs, on-site inspections shall be made at least once during each work shift, and at any time at employee request. For Class II and III jobs, on-site inspections shall be made at intervals sufficient to assess whether conditions have changed, and at any reasonable time at employee request.

(i) On all worksites where employees are engaged in Class I or II asbestos work, the qualified person designated in accordance with paragraph (g)(1) of this section shall perform or supervise the following duties, as applicable:

(A) Set up the regulated area, enclosure, or other containment;

(B) Ensure (by on-site inspection) the integrity of the enclosure or containment;

(C) Set up procedures to control entry to and exit from the enclosure and/or area;

(D) Supervise all employee exposure monitoring required by this section and ensure that it is conducted as required by paragraph (f) of this section;

(E) Ensure that employees working within the enclosure and/or using glove bags wear protective clothing and respirators as required by paragraphs (h) and (i) of this section;

(F) Ensure through on-site supervision, that employees set up and remove engineering controls, use work practices and personal protective equipment in compliance with all requirements;

(G) Ensure that employees use the hygiene facilities and observe the decontamination procedures specified in paragraph (j) of this section;

(H) Ensure that though on-site inspection engineering controls are functioning properly and employees are using proper work practices; and

(I) Ensure that notification requirements in paragraph (f)(6) of this section are met.

(4) Training for the competent person;

(i) For Class I and II asbestos work the qualified person shall be trained in all aspects of asbestos removal and handling, including: abatement, installation, removal and handling; the contents of this standard; the identification of asbestos; removal procedures, where appropriate; and other practices for reducing the hazard. Such training shall be obtained in a comprehensive course for supervisors, such as a course conducted by an EPA or state-approved training provider, certified by the EPA or a state, or an course equivalent in stringency, content, and length.

(ii) For Class III asbestos work operations, the qualified person shall be trained in aspects of asbestos handling appropriate for the nature of the work, to include procedures for setting up glove bags and mini-enclosures, practices for reducing asbestos exposures, use of wet methods, the contents of this standard, and the identification of asbestos. Such training shall be obtained in a comprehensive course for supervisors, such as a course conducted by an EPA or state-approved training provider, certified by the EPA or a state, or an equivalent in stringency, content, and length.

(p) Appendices. (1) Appendices A, C, D, and E to this section are incorporated as part of this section and the contents of these appendices are mandatory.

(2) Appendices B, F, H, I, J, and K to this section are informational and are not intended to create any additional obligations not otherwise imposed or to detract from any existing obligations.

(q) Dates. (1) This standard shall become effective October 11, 1994. (2) The provisions of 29 CFR 1926.58 and 29 CFR 1910.1001 remain in effect until the start-up dates of the equivalent provisions of this standard.

(3) Start-up dates: All obligations of this standard commence on the effective date except as follows:

(i) Methods of compliance. The engineering and work practice controls required by paragraph (g) of this section shall be implemented as soon as possible but no later than April 10, 1995.

(ii) Respiratory protection. Respiratory protection required by paragraph (h) of this section shall be provided as soon as possible but no later than February 8, 1995.

(iii) Hygiene facilities and practices for employees. Hygiene facilities and practices required by paragraph (j) of this section shall be provided as soon as possible but no later than February 8, 1995.

(iv) Communication of hazards. Identification, notification, labeling and sign posting, and training required by paragraph (k) of this section shall be provided as soon as possible, but no later than April 10, 1995.

(v) Housekeeping. Housekeeping practices and controls required by paragraph (l) of this section shall be provided as soon as possible, but no later than January 9, 1995.

(vi) Medical surveillance required by paragraph (m) of this section shall be provided as soon as possible, but no later than January 9, 1995.

(vii) The designation and training of competent persons required by paragraph (o) of this section shall completed as soon as possible but no later than April 10, 1995.

(Approved by the Office of Management and Budget under control number 1218-0195)

Appendix A to 1915.1001. OSHA Reference Method. -- Mandatory

This mandatory appendix specifies the procedure for analyzing air samples for asbestos, tremolite, anthophyllite, and actinolite and specifies quality control procedures that must be implemented by laboratories performing the analysis. The sampling and analytical methods described below represent the elements of the available monitoring methods (such as appendix B to this section, the most current version of the OSHA method ID-60, or the most current version of the NIOSH 7400 method) which OSHA considers to be essential to achieve adequate employee exposure monitoring while allowing employers to use methods that are already established within their organizations. All employers who are required to conduct air monitoring under paragraph (f) of this section are required to utilize analytical laboratories that use this procedure, or an equivalent method, for collecting and analyzing samples.

Sampling and Analytical Procedure

1. The sampling medium for air samples shall be mixed cellulose ester filter membranes. These shall be designated by the manufacturer as suitable for asbestos, tremolite, anthophyllite, and actinolite counting. See below for rejection of blanks.

2. The preferred collection device shall be the 25-mm diameter cassette with an open-faced 50-mm extension cowl. The 37-mm cassette may be used if necessary but only if written justification for the need to use the 37-mm filter cassette accompanies the sample results in the employee's exposure monitoring record. Do not reuse or reload cassettes for asbestos sample collection.

3. An air flow rate between 0.5 liter/min and 2.5 liters/min shall be selected for the 25-mm cassette. If the 37-mm cassette is used, an air flow rate between 1 liter/min and 2.5 liters/min shall be selected.

4. Where possible, a sufficient air volume for each air sample shall be collected to yield between 100 and 1,300 fibers per square millimeter on the membrane filter. If a filter darkens in appearance or if loose dust is seen on the filter, a second sample shall be started.

5. Ship the samples in a rigid container with sufficient packing material to prevent dislodging the collected fibers. Packing material that has a high electrostatic charge on its surface (e.g., expanded polystyrene) cannot be used because such material can cause loss of fibers to the sides of the cassette.

6. Calibrate each personal sampling pump before and after use with a representative filter cassette installed between the pump and the calibration devices.

7. Personal samples shall be taken in the "breathing zone" of the employee (i.e., attached to or near the collar or lapel near the worker's face).

8. Fiber counts shall be made by positive phase contrast using a microscope with an 8 to 10 X eyepiece and a 40 to 45 X objective for a total magnification of approximately 400 X and a numerical aperture of 0.65 to 0.75. The microscope shall also be fitted with a green or blue filter.

9. The microscope shall be fitted with a Walton-Beckett eyepiece graticule calibrated for a field diameter of 100 micrometers (+/- 2 micrometers).

10. The phase-shift detection limit of the microscope shall be about 3 degrees measured using the HSE phase shift test slide as outlined below.

a. Place the test slide on the microscope stage and center it under the phase objective.

b. Bring the blocks of grooved lines into focus.

Note: The slide consists of seven sets of grooved lines (ca. 20 grooves to each block) in descending order of visibility from sets 1 to 7, seven being the least visible. The requirements for asbestos, tremolite, anthophyllite, and actinolite counting are that the microscope optics must resolve the grooved lines in set 3 completely, although they may appear somewhat faint, and that the grooved lines in sets 6 and 7 must be invisible. Sets 4 and 5 must be at least partially visible but may vary slightly in visibility between microscopes. A microscope that fails to meet these requirements has either too low or too high a resolution to be used for asbestos, tremolite, anthophyllite, and actinolite counting.

c. If the image deteriorates, clean and adjust the microscope optics. If the problem persists, consult the microscope manufacturer.

11. Each set of samples taken will include 10 percent blanks or a minimum of 2 blanks. These blanks must come from the same lot as the filters used for sample collection. The field blank results shall be averaged and subtracted from the analytical results before reporting. Any samples represented by a blank having a fiber count in excess of the detection limit of the method being used shall be rejected.

12. The samples shall be mounted by the acetone/triacetin method or a method with an equivalent index of refraction and similar clarity.

13. Observe the following counting rules.

a. Count only fibers equal to or longer than 5 micrometers. Measure the length of curved fibers along the curve.

b. Count all particles as asbestos, tremolite, anthophyllite, and actinolite that have a length-to-width ratio (aspect ratio) of 3:1 or greater.

c. Fibers lying entirely within the boundary of the Walton- Beckett graticule field shall receive a count of 1. Fibers crossing the boundary once, having one end within the circle, shall receive the count of one half (1/2). Do not count any fiber that crosses the graticule boundary more than once. Reject and do not count any other fibers even though they may be visible outside the graticule area.

d. Count bundles of fibers as one fiber unless individual fibers can be identified by observing both ends of an individual fiber.

e. Count enough graticule fields to yield 100 fibers. Count a minimum of 20 fields; stop counting at 100 fields regardless of fiber count.

14. Blind recounts shall be conducted at the rate of 10 percent.

Quality Control Procedures

1. Intra-laboratory program. Each laboratory and/or each company with more than one microscopist counting slides shall establish a statistically designed quality assurance program involving blind recounts and comparisons between microscopists to monitor the variability of counting by each microscopist and between microscopists. In a company with more than one laboratory, the program shall include all laboratories and shall also evaluate the laboratory-to-laboratory variability.

2. a. Interlaboratory program. Each laboratory analyzing asbestos, tremolite, anthophyllite, and actinolite samples for compliance determination shall implement an interlaboratory quality assurance program that as a minimum includes participation of at least two other independent laboratories. Each laboratory shall participate in round robin testing at least once every 6 months with at least all the other laboratories in its interlaboratory quality assurance group. Each laboratory shall submit slides typical of its own work load for use in this program. The round robin shall be designed and results analyzed using appropriate statistical methodology.

b. All laboratories should participate in a national sample testing scheme such as the Proficiency Analytical Testing Program (PAT), the Asbestos Registry sponsored by the American Industrial Hygiene Association (AIHA).

3. All individuals performing asbestos, tremolite, anthophyllite, and actinolite analysis must have taken the NIOSH course for sampling and evaluating airborne asbestos, tremolite, anthophyllite, and actinolite dust or an equivalent course.

4. When the use of different microscopes contributes to differences between counters and laboratories, the effect of the different microscope shall be evaluated and the microscope shall be replaced, as necessary.

5. Current results of these quality assurance programs shall be posted in each laboratory to keep the microscopists informed.

Appendix B to Sec. 1915.1001 -- Detailed Procedures for Asbestos Sampling and Analysis (Non-mandatory)

Air
Matrix:
OSHA Permissible Exposure Limits:
Time Weighted Average 0.1 fiber/cc
Excursion Level (30 minutes) 1.0 fiber/cc
Collection Procedure:
  • A known volume of air is drawn through a 25-mm diameter cassette containing a mixed-cellulose ester filter. The cassette must be equipped with an electrically conductive 50-mm extension cowl. The sampling time and rate are chosen to give a fiber density of between 100 to 1,300 fibers/mm(2) on the filter
Recommended Sampling Rate 0.5 to 5.0 liters/minute (L/min)
Recommended Air Volumes:
  • Minimum
25 L
  • Maximum
2,400 L

Analytical Procedure: A portion of the sample filter is cleared and prepared for asbestos fiber counting by Phase Contrast Microscopy (PCM) at 400X.

Commercial manufacturers and products mentioned in this method are for descriptive use only and do not constitute endorsements by USDOL-OSHA. Similar products from other sources can be substituted.

1. Introduction

This method describes the collection of airborne asbestos fibers using calibrated sampling pumps with mixed-cellulose ester (MCE) filters and analysis by phase contrast microscopy (PCM). Some terms used are unique to this method and are defined below: Asbestos: A term for naturally occurring fibrous minerals. Asbestos includes chrysotile, crocidolite, amosite (cummingtonite-grunerite asbestos), tremolite asbestos, actinolite asbestos, anthophyllite asbestos, and any of these minerals that have been chemically treated and/or altered. The precise chemical formulation of each species will vary with the location from which it was mined. Nominal compositions are listed:

Chrysotile.................... Mg(3)Si(2)O(5)(OH)(4)

Crocidolite................... Na(2)Fe(3)(2)+Fe(2)(3)+Si(8)O(2)2(OH)(2)

Amosite....................... (Mg,Fe)(7)Si(8)O(2)2(OH)(2)

Tremolite-actinolite.......... Ca(2)(Mg,Fe)(5)Si(8)O(2)2(OH)(2)

Anthophyllite................. (Mg,Fe)(7)Si(8)O(2)2(OH)(2)

Asbestos Fiber: A fiber of asbestos which meets the criteria specified below for a fiber.

Aspect Ratio: The ratio of the length of a fiber to it's diameter (e.g. 3:1, 5:1 aspect ratios).

Cleavage Fragments: Mineral particles formed by comminution of minerals, especially those characterized by parallel sides and a moderate aspect ratio (usually less than 20:1).

Detection Limit: The number of fibers necessary to be 95% certain that the result is greater than zero.

Differential Counting: The term applied to the practice of excluding certain kinds of fibers from the fiber count because they do not appear to be asbestos.

Fiber: A particle that is 5 um or longer, with a length-to-width ratio of 3 to 1 or longer.

Field: The area within the graticule circle that is superimposed on the microscope image.

Set: The samples which are taken, submitted to the laboratory, analyzed, and for which, interim or final result reports are generated.

Tremolite, Anthophyllite, and Actinolite: The non-asbestos form of these minerals which meet the definition of a fiber. It includes any of these minerals that have been chemically treated and/or altered.

Walton-Beckett Graticule: An eyepiece graticule specifically designed for asbestos fiber counting. It consists of a circle with a projected diameter of 100 plus or minus 2 um (area of about 0.00785 mm(2)) with a crosshair having tic-marks at 3-um intervals in one direction and 5-um in the orthogonal direction. There are marks around the periphery of the circle to demonstrate the proper sizes and shapes of fibers. This design is reproduced in Figure 2. The disk is placed in one of the microscope eyepieces so that the design is superimposed on the field of view.

1.1. History

Early surveys to determine asbestos exposures were conducted using impinger counts of total dust with the counts expressed as million particles per cubic foot. The British Asbestos Research Council recommended filter membrane counting in 1969. In July 1969, the Bureau of Occupational Safety and Health published a filter membrane method for counting asbestos fibers in the United States. This method was refined by NIOSH and published as P&CAM 239. On May 29, 1971, OSHA specified filter membrane sampling with phase contrast counting for evaluation of asbestos exposures at work sites in the United States. The use of this technique was again required by OSHA in 1986. Phase contrast microscopy has continued to be the method of choice for the measurement of occupational exposure to asbestos.

1.2. Principle

Air is drawn through a MCE filter to capture airborne asbestos fibers. A wedge shaped portion of the filter is removed, placed on a glass microscope slide and made transparent. A measured area (field) is viewed by PCM. All the fibers meeting a defined criteria for asbestos are counted and considered a measure of the airborne asbestos concentration.

1.3. Advantages and Disadvantages

There are four main advantages of PCM over other methods:

(1) The technique is specific for fibers. Phase contrast is a fiber counting technique which excludes non-fibrous particles from the analysis.

(2) The technique is inexpensive and does not require specialized knowledge to carry out the analysis for total fiber counts.

(3) The analysis is quick and can be performed on-site for rapid determination of air concentrations of asbestos fibers.

(4) The technique has continuity with historical epidemiological studies so that estimates of expected disease can be inferred from long-term determinations of asbestos exposures.

The main disadvantage of PCM is that it does not positively identify asbestos fibers. Other fibers which are not asbestos may be included in the count unless differential counting is performed. This requires a great deal of experience to adequately differentiate asbestos from non-asbestos fibers. Positive identification of asbestos must be performed by polarized light or electron microscopy techniques. A further disadvantage of PCM is that the smallest visible fibers are about 0.2 um in diameter while the finest asbestos fibers may be as small as 0.02 um in diameter. For some exposures, substantially more fibers may be present than are actually counted.

1.4. Workplace Exposure

Asbestos is used by the construction industry in such products as shingles, floor tiles, asbestos cement, roofing felts, insulation and acoustical products. Non-construction uses include brakes, clutch facings, paper, paints, plastics, and fabrics. One of the most significant exposures in the workplace is the removal and encapsulation of asbestos in schools, public buildings, and homes. Many workers have the potential to be exposed to asbestos during these operations.

About 95% of the asbestos in commercial use in the United States is chrysotile. Crocidolite and amosite make up most of the remainder. Anthophyllite and tremolite or actinolite are likely to be encountered as contaminants in various industrial products.

1.5. Physical Properties

Asbestos fiber possesses a high tensile strength along its axis, is chemically inert, non-combustible, and heat resistant. It has a high electrical resistance and good sound absorbing properties. It can be weaved into cables, fabrics or other textiles, and also matted into asbestos papers, felts, or mats.

2. Range and Detection Limit

2.1. The ideal counting range on the filter is 100 to 1,300 fibers/mm(2). With a Walton-Beckett graticule this range is equivalent to 0.8 to 10 fibers/field. Using NIOSH counting statistics, a count of 0.8 fibers/field would give an approximate coefficient of variation (CV) of 0.13.

2.2. The detection limit for this method is 4.0 fibers per 100 fields or 5.5 fibers/mm(2). This was determined using an equation to estimate the maximum CV possible at a specific concentration (95% confidence) and a Lower Control Limit of zero. The CV value was then used to determine a corresponding concentration from historical CV vs fiber relationships. As an example:

Lower Control Limit (95% Confidence) = AC -- 1.645(CV)(AC)

Where:

AC = Estimate of the airborne fiber concentration (fibers/cc)

Setting the Lower Control Limit = 0 and solving for CV:

0 = AC -- 1.645(CV)(AC) CV = 0.61 This value was compared with CV vs. count curves. The count at which CV = 0.61 for Leidel-Busch counting statistics (8.9.) or for an OSHA Salt Lake Technical Center (OSHA-SLTC) CV curve (see Appendix A for further information) was 4.4 fibers or 3.9 fibers per 100 fields, respectively. Although a lower detection limit of 4 fibers per 100 fields is supported by the OSHA-SLTC data, both data sets support the 4.5 fibers per 100 fields value.

3. Method Performance -- Precision and Accuracy

Precision is dependent upon the total number of fibers counted and the uniformity of the fiber distribution on the filter. A general rule is to count at least 20 and not more than 100 fields. The count is discontinued when 100 fibers are counted, provided that 20 fields have already been counted. Counting more than 100 fibers results in only a small gain in precision. As the total count drops below 10 fibers, an accelerated loss of precision is noted.

At this time, there is no known method to determine the absolute accuracy of the asbestos analysis. Results of samples prepared through the Proficiency Analytical Testing (PAT) Program and analyzed by the OSHA-SLTC showed no significant bias when compared to PAT reference values. The PAT samples were analyzed from 1987 to 1989 (N=36) and the concentration range was from 120 to 1,300 fibers/mm(2).

4. Interferences

Fibrous substances, if present, may interfere with asbestos analysis. Some common fibers are:

Fiber glass........................ Perlite veins.

Anhydrite plant fibers gypsum...... Some synthetic fibers.

Membrane structures................ Sponge spicules and diatoms.

Microorganisms..................... Wollastonite.

The use of electron microscopy or optical tests such as polarized light, and dispersion staining may be used to differentiate these materials from asbestos when necessary.

5. Sampling

5.1. Equipment

5.1.1. Sample assembly (The assembly is shown in Figure 3). Conductive filter holder consisting of a 25-mm diameter, 3-piece cassette having a 50-mm long electrically conductive extension cowl. Backup pad, 25-mm, cellulose. Membrane filter, mixed-cellulose ester (MCE), 25-mm, plain, white, 0.8- to 1.2-um pore size.

Notes: (a) DO NOT RE-USE CASSETTES. (b) Fully conductive cassettes are required to reduce fiber loss to the sides of the cassette due to electrostatic attraction. (c) Purchase filters which have been selected by the manufacturer for asbestos counting or analyze representative filters for fiber background before use. Discard the filter lot if more than 4 fibers/100 fields are found. (d) To decrease the possibility of contamination, the sampling system (filter-backup pad-cassette) for asbestos is usually preassembled by the manufacturer.

5.1.2. Gel bands for sealing cassettes.

5.1.3. Sampling pump. Each pump must be a battery operated, self-contained unit small enough to be placed on the monitored employee and not interfere with the work being performed. The pump must be capable of sampling at 2.5 liters per minute (L/min) for the required sampling time.

5.1.4. Flexible tubing, 6-mm bore.

5.1.5. Pump calibration. Stopwatch and bubble tube/burette or electronic meter.

5.2. Sampling Procedure

5.2.1. Seal the point where the base and cowl of each cassette meet (see Figure 3) with a gel band or tape.

5.2.2. Charge the pumps completely before beginning.

5.2.3. Connect each pump to a calibration cassette with an appropriate length of 6-mm bore plastic tubing. Do not use luer connectors -- the type of cassette specified above has built-in adapters.

5.2.4. Select an appropriate flow rate for the situation being monitored. The sampling flow rate must be between 0.5 and 5.0 L/min for personal sampling and is commonly set between 1 and 2 L/min. Always choose a flow rate that will not produce overloaded filters.

5.2.5. Calibrate each sampling pump before and after sampling with a calibration cassette in-line (Note: This calibration cassette should be from the same lot of cassettes used for sampling). Use a primary standard (e.g. bubble burette) to calibrate each pump. If possible, calibrate at the sampling site.

Note: If sampling site calibration is not possible, environmental influences may affect the flow rate. The extent is dependent on the type of pump used. Consult with the pump manufacturer to determine dependence on environmental influences. If the pump is affected by temperature and pressure changes, use the formula in Appendix B to this section to calculate the actual flow rate.

5.2.6. Connect each pump to the base of each sampling cassette with flexible tubing. Remove the end cap of each cassette and take each air sample open face. Assure that each sample cassette is held open side down in the employee's breathing zone during sampling. The distance from the nose/mouth of the employee to the cassette should be about 10 cm. Secure the cassette on the collar or lapel of the employee using spring clips or other similar devices.

5.2.7. A suggested minimum air volume when sampling to determine TWA compliance is 25 L. For Excursion Limit (30 min sampling time) evaluations, a minimum air volume of 48 L is recommended.

5.2.8. The most significant problem when sampling for asbestos is overloading the filter with non-asbestos dust. Suggested maximum air sample volumes for specific environments are:

Environment (L)
Asbestos removal operations (visible dust) 100
Asbestos removal operations (little dust) 240
Office environments 400 to 2,400

Caution: Do not overload the filter with dust. High levels of non-fibrous dust particles may obscure fibers on the filter and lower the count or make counting impossible. If more than about 25 to 30% of the field area is obscured with dust, the result may be biased low. Smaller air volumes may be necessary when there is excessive non-asbestos dust in the air.

While sampling, observe the filter with a small flashlight. If there is a visible layer of dust on the filter, stop sampling, remove and seal the cassette, and replace with a new sampling assembly. The total dust loading should not exceed 1 mg.

5.2.9. Blank samples are used to determine if any contamination has occurred during sample handling. Prepare two blanks for the first 1 to 20 samples. For sets containing greater than 20 samples, prepare blanks as 10% of the samples. Handle blank samples in the same manner as air samples with one exception: Do not draw any air through the blank samples. Open the blank cassette in the place where the sample cassettes are mounted on the employee. Hold it open for about 30 seconds. Close and seal the cassette appropriately. Store blanks for shipment with the sample cassettes.

5.2.10. Immediately after sampling, close and seal each cassette with the base and plastic plugs. Do not touch or puncture the filter membrane as this will invalidate the analysis.

5.2.11. Attach a seal (OSHA-21 or equivalent) around each cassette in such a way as to secure the end cap plug and base plug. Tape the ends of the seal together since the seal is not long enough to be wrapped end-to-end. Also wrap tape around the cassette at each joint to keep the seal secure.

5.3. Sample Shipment

5.3.1. Send the samples to the laboratory with paperwork requesting asbestos analysis. List any known fibrous interferences present during sampling on the paperwork. Also, note the workplace operation(s) sampled.

5.3.2. Secure and handle the samples in such that they will not rattle during shipment nor be exposed to static electricity. Do not ship samples in expanded polystyrene peanuts, vermiculite, paper shreds, or excelsior. Tape sample cassettes to sheet bubbles and place in a container that will cushion the samples without rattling.

5.3.3. To avoid the possibility of sample contamination, always ship bulk samples in separate mailing containers.

6. Analysis

6.1. Safety Precautions

6.1.1. Acetone is extremely flammable and precautions must be taken not to ignite it. Avoid using large containers or quantities of acetone. Transfer the solvent in a ventilated laboratory hood. Do not use acetone near any open flame. For generation of acetone vapor, use a spark free heat source.

6.1.2. Any asbestos spills should be cleaned up immediately to prevent dispersal of fibers. Prudence should be exercised to avoid contamination of laboratory facilities or exposure of personnel to asbestos. Asbestos spills should be cleaned up with wet methods and/ or a High Efficiency Particulate-Air (HEPA) filtered vacuum.

Caution: Do not use a vacuum without a HEPA filter -- It will disperse fine asbestos fibers in the air.

6.2. Equipment

6.2.1. Phase contrast microscope with binocular or trinocular head.

6.2.2. Widefield or Huygenian 10X eyepieces (NOTE: The eyepiece containing the graticule must be a focusing eyepiece. Use a 40X phase objective with a numerical aperture of 0.65 to 0.75).

6.2.3. Kohler illumination (if possible) with green or blue filter. 6.2.4. Walton-Beckett Graticule, type G-22 with 100 plus or minus 2 um projected diameter.

6.2.5. Mechanical stage. A rotating mechanical stage is convenient for use with polarized light.

6.2.6. Phase telescope.

6.2.7. Stage micrometer with 0.01-mm subdivisions.

6.2.8. Phase-shift test slide, mark II (Available from PTR optics Ltd., and also McCrone).

6.2.9. Precleaned glass slides, 25 mm X 75 mm. One end can be frosted for convenience in writing sample numbers, etc., or paste-on labels can be used.

6.2.10. Cover glass #1 1/2.

6.2.11. Scalpel (#10, curved blade).

6.2.12. Fine tipped forceps.

6.2.13. Aluminum block for clearing filter (see Appendix D and Figure 4).

6.2.14. Automatic adjustable pipette, 100- to 500-uL.

6.2.15. Micropipette, 5 uL.

6.3. Reagents

6.3.1. Acetone (HPLC grade).

6.3.2. Triacetin (glycerol triacetate).

6.3.3. Lacquer or nail polish.

6.4. Standard Preparation

A way to prepare standard asbestos samples of known concentration has not been developed. It is possible to prepare replicate samples of nearly equal concentration. This has been performed through the PAT program. These asbestos samples are distributed by the AIHA to participating laboratories.

Since only about one-fourth of a 25-mm sample membrane is required for an asbestos count, any PAT sample can serve as a "standard" for replicate counting.

6.5. Sample Mounting

Note: See Safety Precautions in Section 6.1. before proceeding. The objective is to produce samples with a smooth (non-grainy) background in a medium with a refractive index of approximately 1.46. The technique below collapses the filter for easier focusing and produces permanent mounts which are useful for quality control and interlaboratory comparison.

An aluminum block or similar device is required for sample preparation.

 

6.5.1. Heat the aluminum block to about 70 deg. C. The hot block should not be used on any surface that can be damaged by either the heat or from exposure to acetone.

6.5.2. Ensure that the glass slides and cover glasses are free of dust and fibers.

6.5.3. Remove the top plug to prevent a vacuum when the cassette is opened. Clean the outside of the cassette if necessary. Cut the seal and/or tape on the cassette with a razor blade. Very carefully separate the base from the extension cowl, leaving the filter and backup pad in the base.

6.5.4. With a rocking motion cut a triangular wedge from the filter using the scalpel. This wedge should be one-sixth to one- fourth of the filter. Grasp the filter wedge with the forceps on the perimeter of the filter which was clamped between the cassette pieces. DO NOT TOUCH the filter with your finger. Place the filter on the glass slide sample side up. Static electricity will usually keep the filter on the slide until it is cleared.

6.5.5. Place the tip of the micropipette containing about 200 uL acetone into the aluminum block. Insert the glass slide into the receiving slot in the aluminum block. Inject the acetone into the block with slow, steady pressure on the plunger while holding the pipette firmly in place. Wait 3 to 5 seconds for the filter to clear, then remove the pipette and slide from the aluminum block.

6.5.6. Immediately (less than 30 seconds) place 2.5 to 3.5 uL of triacetin on the filter (Note: Waiting longer than 30 seconds will result in increased index of refraction and decreased contrast between the fibers and the preparation. This may also lead to separation of the cover slip from the slide).

6.5.7. Lower a cover slip gently onto the filter at a slight angle to reduce the possibility of forming air bubbles. If more than 30 seconds have elapsed between acetone exposure and triacetin application, glue the edges of the cover slip to the slide with lacquer or nail polish.

6.5.8. If clearing is slow, warm the slide for 15 min on a hot plate having a surface temperature of about 50 deg. C to hasten clearing. The top of the hot block can be used if the slide is not heated too long.

6.5.9. Counting may proceed immediately after clearing and mounting are completed.

6.6. Sample Analysis

Completely align the microscope according to the manufacturer's instructions. Then, align the microscope using the following general alignment routine at the beginning of every counting session and more often if necessary.

6.6.1. Alignment

(1) Clean all optical surfaces. Even a small amount of dirt can significantly degrade the image.

(2) Rough focus the objective on a sample.

(3) Close down the field iris so that it is visible in the field of view. Focus the image of the iris with the condenser focus. Center the image of the iris in the field of view.

(4) Install the phase telescope and focus on the phase rings. Critically center the rings. Misalignment of the rings results in astigmatism which will degrade the image.

(5) Place the phase-shift test slide on the microscope stage and focus on the lines. The analyst must see line set 3 and should see at least parts of 4 and 5 but, not see line set 6 or 6. A microscope/microscopist combination which does not pass this test may not be used.

6.6.2. Counting Fibers

(1) Place the prepared sample slide on the mechanical stage of the microscope. Position the center of the wedge under the objective lens and focus upon the sample.

(2) Start counting from one end of the wedge and progress along a radial line to the other end (count in either direction from perimeter to wedge tip). Select fields randomly, without looking into the eyepieces, by slightly advancing the slide in one direction with the mechanical stage control.

(3) Continually scan over a range of focal planes (generally the upper 10 to 15 um of the filter surface) with the fine focus control during each field count. Spend at least 5 to 15 seconds per field.

(4) Most samples will contain asbestos fibers with fiber diameters less than 1 um. Look carefully for faint fiber images. The small diameter fibers will be very hard to see. However, they are an important contribution to the total count.

(5) Count only fibers equal to or longer than 5 um. Measure the length of curved fibers along the curve.

(6) Count fibers which have a length to width ratio of 3:1 or greater.

(7) Count all the fibers in at least 20 fields. Continue counting until either 100 fibers are counted or 100 fields have been viewed; whichever occurs first. Count all the fibers in the final field.

(8) Fibers lying entirely within the boundary of the Walton- Beckett graticule field shall receive a count of 1. Fibers crossing the boundary once, having one end within the circle shall receive a count of 1/2. Do not count any fiber that crosses the graticule boundary more than once. Reject and do not count any other fibers even though they may be visible outside the graticule area. If a fiber touches the circle, it is considered to cross the line.

(9) Count bundles of fibers as one fiber unless individual fibers can be clearly identified and each individual fiber is clearly not connected to another counted fiber. See Figure 2 for counting conventions.

(10) Record the number of fibers in each field in a consistent way such that filter non-uniformity can be assessed.

(11) Regularly check phase ring alignment.

(12) When an agglomerate (mass of material) covers more than 25% of the field of view, reject the field and select another. Do not include it in the number of fields counted.

(13) Perform a "blind recount" of 1 in every 10 filter wedges (slides). Re-label the slides using a person other than the original counter.

6.7. Fiber Identification

As previously mentioned in Section 1.3., PCM does not provide positive confirmation of asbestos fibers. Alternate differential counting techniques should be used if discrimination is desirable. Differential counting may include primary discrimination based on morphology, polarized light analysis of fibers, or modification of PCM data by Scanning Electron or Transmission Electron Microscopy.

A great deal of experience is required to routinely and correctly perform differential counting. It is discouraged unless it is legally necessary. Then, only if a fiber is obviously not asbestos should it be excluded from the count. Further discussion of this technique can be found in reference 8.10.

If there is a question whether a fiber is asbestos or not, follow the rule:

"WHEN IN DOUBT, COUNT."

6.8. Analytical Recommendations -- Quality Control System

6.8.1. All individuals performing asbestos analysis must have taken the NIOSH course for sampling and evaluating airborne asbestos or an equivalent course.

6.8.2. Each laboratory engaged in asbestos counting shall set up a slide trading arrangement with at least two other laboratories in order to compare performance and eliminate inbreeding of error. The slide exchange occurs at least semiannually. The round robin results shall be posted where all analysts can view individual analyst's results.

6.8.3. Each laboratory engaged in asbestos counting shall participate in the Proficiency Analytical Testing Program, the Asbestos Analyst Registry or equivalent.

6.8.4. Each analyst shall select and count prepared slides from a "slide bank". These are quality assurance counts. The slide bank shall be prepared using uniformly distributed samples taken from the workload. Fiber densities should cover the entire range routinely analyzed by the laboratory. These slides are counted blind by all counters to establish an original standard deviation. This historical distribution is compared with the quality assurance counts. A counter must have 95% of all quality control samples counted within three standard deviations of the historical mean. This count is then integrated into a new historical mean and standard deviation for the slide.

The analyses done by the counters to establish the slide bank may be used for an interim quality control program if the data are treated in a proper statistical fashion.

7. Calculations

7.1. Calculate the estimated airborne asbestos fiber concentration on the filter sample using the following formula:

(For Equation, see paper copy)

Where:
AC = Airborne fiber concentration
FB = Total number of fibers greater than 5 um counted
FL = Total number of fields counted on the filter
BFB = Total number of fibers greater than 5 um counted in the blank
BFL = Total number of fields counted on the blank
ECA = Effective collecting area of filter (385 mm(2) nominal for a 25-mm filter.)
FR = Pump flow rate (L/min)
MFA = Microscope count field area (mm(2)). This is 0.00785 mm(2) for a Walton-Beckett Graticule
T = Sample collection time (min)
1,000 = Conversion of L to cc

Note: The collection area of a filter is seldom equal to 385 mm(2). It is appropriate for laboratories to routinely monitor the exact diameter using an inside micrometer. The collection area is calculated according to the formula:

Area = Pie(d/2)(2)

7.2. Short-cut Calculation

Since a given analyst always has the same interpupillary distance, the number of fields per filter for a particular analyst will remain constant for a given size filter. The field size for that analyst is constant (i.e. the analyst is using an assigned microscope and is not changing the reticle).

For example, if the exposed area of the filter is always 385 mm(2) and the size of the field is always 0.00785 mm(2), the number of fields per filter will always be 49,000. In addition it is necessary to convert liters of air to cc. These three constants can then be combined such that ECA/(1,000 X MFA) = 49. The previous equation simplifies to:

 

(For Equation, see paper copy)

 

7.3. Recount Calculations

As mentioned in step 13 of Section 6.6.2., a "blind recount" of 10% of the slides is performed. In all cases, differences will be observed between the first and second counts of the same filter wedge. Most of these differences will be due to chance alone, that is, due to the random variability (precision) of the count method. Statistical recount criteria enables one to decide whether observed differences can be explained due to chance alone or are probably due to systematic differences between analysts, microscopes, or other biasing factors.

The following recount criterion is for a pair of counts that estimate AC in fibers/cc. The criterion is given at the type-I error level. That is, there is 5% maximum risk that we will reject a pair of counts for the reason that one might be biased, when the large observed difference is really due to chance.

Reject a pair of counts if:

(For Equation, see paper copy)

Where:
AC(1) = lower estimated airborne fiber concentration
AC(2) = higher estimated airborne fiber concentration
AC(avg) = average of the two concentration estimates
CV(FB) = CV for the average of the two concentration estimates

If a pair of counts are rejected by this criterion then, recount the rest of the filters in the submitted set. Apply the test and reject any other pairs failing the test. Rejection shall include a memo to the industrial hygienist stating that the sample failed a statistical test for homogeneity and the true air concentration may be significantly different than the reported value.

7.4. Reporting Results

Report results to the industrial hygienist as fibers/cc. Use two significant figures. If multiple analyses are performed on a sample, an average of the results is to be reported unless any of the results can be rejected for cause.

8. References

8.1. Dreesen, W.C., et al, U.S. Public Health Service: A Study of Asbestosis in the Asbestos Textile Industry, (Public Health Bulletin No. 241), US Treasury Dept., Washington, DC, 1938.

8.2. Asbestos Research Council: The Measurement of Airborne Asbestos Dust by the Membrane Filter Method (Technical Note), Asbestos Research Council, Rockdale, Lancashire, Great Britain, 1969.

8.3. Bayer, S.G., Zumwalde, R.D., Brown, T.A., Equipment and Procedure for Mounting Millipore Filters and Counting Asbestos Fibers by Phase Contrast Microscopy, Bureau of Occupational Health, U.S. Dept. of Health, Education and Welfare, Cincinnati,OH,1969.

8.4. NIOSH Manual of Analytical Methods, 2nd ed., Vol. 1 (DHEW/ NIOSH Pub. No. 77-157-A). National Institute for Occupational Safety and Health, Cincinnati, OH, 1977.pp.239-1-239-21.

8.5. Asbestos, Code of Federal Regulations 29 CFR 1910.1001. 1971.

8.6. Occupational Exposure to Asbestos, Tremolite, Anthophyllite, and Actinolite. Final Rule, Federal Register 51: 119 (20 June 1986). pp.22612-22790.

8.7. Asbestos, Tremolite, Anthophyllite, and Actinolite, Code of Federal Regulations 1910.1001. 1988. pp 711-752.

8.8. Criteria for a Recommended Standard -- Occupational Exposure to Asbestos (DHEW/NIOSH Pub. No. HSM 72-10267), National Institute for Occupational Safety and Health NIOSH, Cincinnati, OH, 1972. pp. III-1-III-24.

8.9. Leidel, N.A., Bayer, S.G., Zumwalde, R.D., Busch, K.A., USPHS/NIOSH Membrane Filter Method for Evaluating Airborne Asbestos Fibers (DHEW/NIOSH Pub. No. 79-127). National Institute for Occupational Safety and Health, Cincinnati, OH, 1979.

8.10. Dixon, W.C., Applications of Optical Microscopy in Analysis of Asbestos and Quartz, Analytical Techniques in Occupational Health Chemistry, edited by D.D. Dollberg and A.W. Verstuyft. Wash. D.C.: American Chemical Society, (ACS Symposium Series 120) 1980. pp. 13-41.

Quality Control

The OSHA asbestos regulations require each laboratory to establish a quality control program. The following is presented as an example of how the OSHA-SLTC constructed its internal CV curve as part of meeting this requirement. Data for the CV curve shown below is from 395 samples collected during OSHA compliance inspections and analyzed from October 1980 through April 1986.

Each sample was counted by 2 to 5 different counters independently of one another. The standard deviation and the CV statistic was calculated for each sample. This data was then plotted on a graph of CV vs. fibers/mm(2). A least squares regression was performed using the following equation:

CV=antilog(10)[A(log(10)(x))(2) + B(log(10)(x)) + C]

Where:

 

  • x = the number of fibers/mm(2)

 

Application of least squares gave:

 

  • A = 0.182205
    B = - 0.973343
    C = 0.327499

 

Using these values, the equation becomes:

CV = antilog(10)[0.182205(log(10)

  • (x))(2) - 0.973343(log (10)(x)) + 0.327499]

 

Sampling Pump Flow Rate Corrections

This correction is used if a difference greater than 5% in ambient temperature and/or pressure is noted between calibration and sampling sites and the pump does not compensate for the differences.

(For Equation, see paper copy)

Where:
Q(act) = actual flow rate
Q(cal) = calibrated flow rate (if a rotameter was used, the rotameter value)
P(cal) = uncorrected air pressure at calibration
P(act) = uncorrected air pressure at sampling site
T(act) = temperature at sampling site (K)
T(cal) = temperature at calibration (K)

Walton-Beckett Graticule

When ordering the Graticule for asbestos counting, specify the exact disc diameter needed to fit the ocular of the microscope and the diameter (mm) of the circular counting area. Instructions for measuring the dimensions necessary are listed:

(1) Insert any available graticule into the focusing eyepiece and focus so that the graticule lines are sharp and clear.

(2) Align the microscope.

(3) Place a stage micrometer on the microscope object stage and focus the microscope on the graduated lines.

(4) Measure the magnified grid length, PL (um), using the stage micrometer.

(5) Remove the graticule from the microscope and measure its actual grid length, AL (mm). This can be accomplished by using a mechanical stage fitted with verniers, or a jeweler's loupe with a direct reading scale.

(6) Let D=100 um. Calculate the circle diameter, d(c)(mm), for the Walton-Beckett graticule and specify the diameter when making a purchase:

d(c) = AL x D
-- -- -- -- -- --
PL

 

  • Example: If PL=108 um, AL=2.93 mm and D=100 um, then,

 

d(c) = 2.93 x 100
-- -- -- -- -- --
108
= 2.71mm

(7) Each eyepiece-objective-reticle combination on the microscope must be calibrated. Should any of the three be changed (by zoom adjustment, disassembly, replacement, etc.), the combination must be recalibrated. Calibration may change if interpupillary distance is changed.

Measure the field diameter, D (acceptable range: 100 plus or minus 2 um) with a stage micrometer upon receipt of the graticule from the manufacturer. Determine the field area (mm(2)).

Field Area = Pie(D/2)(2) If D = 100 um = 0.1 mm, then Field Area = Pie(0.1 mm/2)(2) = 0.00785 mm(2)

The Graticule is available from: Graticules Ltd., Morley Road, Tonbridge TN9 IRN, Kent, England (Telephone 011-44-732-359061). Also available from PTR Optics Ltd., 145 Newton Street, Waltham, MA 02154 [telephone (617) 891-6000] or McCrone Accessories and Components, 2506 S. Michigan Ave., Chicago, IL 60616 [phone (312) 842-7100]. The graticule is custom made for each microscope.

(For Figure 1, Walton-Beckett Graticule with some
explanatory fibers, see paper copy)

Counts for the Fibers in the Figure
Structure No Count Explanation
1 to 6 1 Single fibers all contained within the circle
7 1/2 Fiber crosses circle once
8 0 Fiber too short
9 2 Two crossing fibers
10 0 Fiber outside graticule
11 0 Fiber crosses graticule twice
12 1/2 Although split, fiber only crosses once

Appendix C to 1915.1001 -- Qualitative and Quantitative Fit Testing Procedures. Mandatory

Qualitative Fit Test Protocols

I. Isoamyl Acetate Protocol

A. Odor threshold screening. 1. Three 1-liter glass jars with metal lids (e.g. Mason or Bell jars) are required.

2. Odor-free water (e.g. distilled or spring water) at approximately 25 deg.C shall be used for the solutions.

3. The isoamyl acetate (IAA)(also known as isopentyl acetate) stock solution is prepared by adding 1 cc of pure IAA to 800 cc of odor free water in a 1-liter jar and shaking for 30 seconds. This solution shall be prepared new at least weekly.

4. The screening test shall be conducted in a room separate from the room used for actual fit testing. The two rooms shall be well ventilated but shall not be connected to the same recirculating ventilation system.

5. The odor test solution is prepared in a second jar by placing 0.4 cc of the stock solution into 500 cc of odor free water using a clean dropper or pipette. Shake for 30 seconds and allow to stand for two to three minutes so that the IAA concentration above the liquid may reach equilibrium. This solution may be used for only one day.

6. A test blank is prepared in a third jar by adding 500 cc of odor free water.

7. The odor test and test blank jars shall be labelled 1 and 2 for jar identification. If the labels are put on the lids they can be periodically peeled, dried off and switched to maintain the integrity of the test.

8. The following instructions shall be typed on a card and placed on the table in front of the two test jars (i.e. 1 and 2): "The purpose of this test is to determine if you can smell banana oil at a low concentration. The two bottles in front of you contain water. One of these bottles also contains a small amount of banana oil. Be sure the covers are on tight, then shake each bottle for two seconds. Unscrew the lid of each bottle, one at a time, and sniff at the mouth of the bottle. Indicate to the test conductor which bottle contains banana oil."

9. The mixtures used in the IAA odor detection test shall be prepared in an area separate from where the test is performed, in order to prevent olfactory fatigue in the subject.

10. If the test subject is unable to correctly identify the jar containing the odor test solution, the IAA qualitative fit test may not be used.

11. If the test subject correctly identifies the jar containing the odor test solution, the test subject may proceed to respirator selection and fit testing.

B. Respirator Selection. 1. The test subject shall be allowed to pick the most comfortable respirator from a selection including respirators of various sizes from different manufacturers. The selection shall include at least five sizes of elastomeric half facepieces, from at least two manufacturers.

2. The selection process shall be conducted in a room separate from the fit-test chamber to prevent odor fatigue. Prior to the selection process, the test subject shall be shown how to put on a respirator, how it should be positioned on the face, how to set strap tension and how to determine a "comfortable" respirator. A mirror shall be available to assist the subject in evaluating the fit and positioning of the respirator. This instruction may not constitute the subject's formal training on respirator use, as it is only a review.

3. The test subject should understand that the employee is being asked to select the respirator which provides the most comfortable fit. Each respirator represents a different size and shape and, if fit properly and used properly will provide adequate protection.

4. The test subject holds each facepiece up to the face and eliminates those which obviously do not give a comfortable fit. Normally, selection will begin with a half-mask and if a good fit cannot be found, the subject will be asked to test the full facepiece respirators. (A small percentage of users will not be able to wear any half-mask.) 5. The more comfortable facepieces are noted; the most comfortable mask is donned and worn at least five minutes to assess comfort. All donning and adjustments of the facepiece shall be performed by the test subject without assistance from the test conductor or other person. Assistance in assessing comfort can be given by discussing the points in #6 below. If the test subject is not familiar with using a particular respirator, the test subject shall be directed to don the mask several times and to adjust the straps each time to become adept at setting proper tension on the straps.

6. Assessment of comfort shall include reviewing the following points with the test subject and allowing the test subject adequate time to determine the comfort of the respirator:

* Positioning of mask on nose. * Room for eye protection. * Room to talk. * Positioning mask on face and cheeks.

7. The following criteria shall be used to help determine the adequacy of the respirator fit:

* Chin properly placed. * Strap tension. * Fit across nose bridge. * Distance from nose to chin. * Tendency to slip. * Self-observation in mirror.

 

8. The test subject shall conduct the conventional negative and positive-pressure fit checks (e.g. see ANSI Z88.2-1980). Before conducting the negative- or positive-pressure test the subject shall be told to "seat" the mask by rapidly moving the head from side-to-side and up and down, while taking a few deep breaths.

9. The test subject is now ready for fit testing.

10. After passing the fit test, the test subject shall be questioned again regarding the comfort of the respirator. If it has become uncomfortable, another model of respirator shall be tried.

11. The employee shall be given the opportunity to select a different facepiece and be retested if the chosen facepiece becomes increasingly uncomfortable at any time.

C. Fit test. 1. The fit test chamber shall be similar to a clear 55 gal drum liner suspended inverted over a 2 foot diameter frame, so that the top of the chamber is about 6 inches above the test subject's head. The inside top center of the chamber shall have a small hook attached.

2. Each respirator used for the fitting and fit testing shall be equipped with organic vapor cartridges or offer protection against organic vapors. The cartridges or masks shall be changed at least weekly.

3. After selecting, donning, and properly adjusting a respirator, the test subject shall wear it to the fit testing room. This room shall be separate from the room used for odor threshold screening and respirator selection, and shall be well ventilated, as by an exhaust fan or lab hood, to prevent general room contamination.

4. A copy of the following test exercises and rainbow passage shall be taped to the inside of the test chamber:

Test Exercises

i. Breathe normally.

ii. Breathe deeply. Be certain breaths are deep and regular.

iii. Turn head all the way from one side to the other. Inhale on each side. Be certain movement is complete. Do not bump the respirator against the shoulders.

iv. Nod head up-and-down. Inhale when head is in the full up position (looking toward ceiling). Be certain motions are complete and made about every second. Do not bump the respirator on the chest.

v. Talking. Talk aloud and slowly for several minutes. The following paragraph is called the Rainbow Passage. Reading it will result in a wide range of facial movements, and thus be useful to satisfy this requirement. Alternative passages which serve the same purpose may also be used.

vi. Jogging in place. vii. Breathe normally.

Rainbow Passage

When the sunlight strikes raindrops in the air, they act like a prism and form a rainbow. The rainbow is a division of white light into many beautiful colors. These take the shape of a long round arch, with its path high above, and its two ends apparently beyond the horizon. There is, according to legend, a boiling pot of gold at one end. People look, but no one ever finds it. When a man looks for something beyond reach, his friends say he is looking for the pot of gold at the end of the rainbow.

5. Each test subject shall wear the respirator for at a least 10 minutes before starting the fit test.

6. Upon entering the test chamber, the test subject shall be given a 6 inch by 5 inch piece of paper towel or other porous absorbent single ply material, folded in half and wetted with three- quarters of one cc of pure IAA. The test subject shall hang the wet towel on the hook at the top of the chamber.

7. Allow two minutes for the IAA test concentration to be reached before starting the fit-test exercises. This would be an appropriate time to talk with the test subject, to explain the fit test, the importance of cooperation, the purpose for the head exercises, or to demonstrate some of the exercises.

8. Each exercise described in #4 above shall be performed for at least one minute.

9. If at any time during the test, the subject detects the banana-like odor of IAA, the test has failed. The subject shall quickly exit from the test chamber and leave the test area to avoid olfactory fatigue.

10. If the test is failed, the subject shall return to the selection room and remove the respirator, repeat the odor sensitivity test, select and put on another respirator, return to the test chamber, and again begin the procedure described in the c(4) through c(8) above. The process continues until a respirator that fits well has been found. Should the odor sensitivity test be failed, the subject shall wait about 5 minutes before retesting. Odor sensitivity will usually have returned by this time.

11. If a person cannot pass the fit test described above wearing a half-mask respirator from the available selection, full facepiece models must be used.

12. When a respirator is found that passes the test, the subject breaks the faceseal and takes a breath before exiting the chamber. This is to assure that the reason the test subject is not smelling the IAA is the good fit of the respirator facepiece seal and not olfactory fatigue.

13. When the test subject leaves the chamber, the subject shall remove the saturated towel and return it to the person conducting the test. To keep the area from becoming contaminated, the used towels shall be kept in a self-sealing bag so there is no significant IAA concentration buildup in the test chamber during subsequent tests.

14. At least two facepieces shall be selected for the IAA test protocol. The test subject shall be given the opportunity to wear them for one week to choose the one which is more comfortable to wear.

15. Persons who have successfully passed this fit test with a half-mask respirator may be assigned the use of the test respirator in atmospheres with up to 10 times the PEL of airborne asbestos. In atmospheres greater than 10 times, and less than 100 times the PEL (up to 100 ppm), the subject must pass the IAA test using a full face negative pressure respirator. (The concentration of the 1AA inside the test chamber must be increased by ten times for QLFT of the full facepiece.) 16. The test shall not be conducted if there is any hair growth between the skin the facepiece sealing surface.

17. If hair growth or apparel interfere with a satisfactory fit, then they shall be altered or removed so as to eliminate interference and allow a satisfactory fit. If a satisfactory fit is still not attained, the test subject must use a positive-pressure respirator such as powered air-purifying respirators, supplied air respirator, or self-contained breathing apparatus.

18. If a test subject exhibits difficulty in breathing during the tests, she or he shall be referred to a physician trained in respirator diseases or pulmonary medicine to determine whether the test subject can wear a respirator while performing her or his duties.

19. Qualitative fit testing shall be repeated at least every six months.

20. In addition, because the sealing of the respirator may be affected, qualitative fit testing shall be repeated immediately when the test subject has a:

(1) Weight change of 20 pounds or more, (2) Significant facial scarring in the area of the facepiece seal, (3) Significant dental changes; i.e.; multiple extractions without prothesis, or acquiring dentures, (4) Reconstructive or cosmetic surgery, or (5) Any other condition that may interfere with facepiece sealing.

D. Recordkeeping. A summary of all test results shall be maintained in each office for 3 years. The summary shall include:

(1) Name of test subject. (2) Date of testing. (3) Name of the test conductor. (4) Respirators selected (indicate manufacturer, model, size and approval number). (5) Testing agent.

II. Saccharin Solution Aerosol Protocol

A. Respirator selection. Respirators shall be selected as described in section IB (respirator selection) above, except that each respirator shall be equipped with a particulate filter.

B. Taste Threshold Screening. 1. An enclosure about head and shoulders shall be used for threshold screening (to determine if the individual can taste saccharin) and for fit testing. The enclosure shall be approximately 12 inches in diameter by 14 inches tall with at least the front clear to allow free movement of the head when a respirator is worn.

2. The test enclosure shall have a three-quarter inch hole in front of the test subject's nose and mouth area to accommodate the nebulizer nozzle.

3. The entire screening and testing procedure shall be explained to the test subject prior to conducting the screening test.

4. During the threshold screening test, the test subject shall don the test enclosure and breathe with open mouth with tongue extended.

5. Using a DeVilbiss Model 40 Inhalation Medication Nebulizer or equivalent, the test conductor shall spray the threshold check solution into the enclosure. This nebulizer shall be clearly marked to distinguish it from the fit test solution nebulizer.

6. The threshold check solution consists of 0.83 grams of sodium saccharin, USP in water. It can be prepared by putting 1 cc of the test solution (see C 7 below) in 100 cc of water.

7. To produce the aerosol, the nebulizer bulb is firmly squeezed so that it collapses completely, then is released and allowed to fully expand.

8. Ten squeezes of the nebulizer bulb are repeated rapidly and then the test subject is asked whether the saccharin can be tasted.

9. If the first response is negative, ten more squeezes of the nebulizer bulb are repeated rapidly and the test subject is again asked whether the saccharin can be tasted.

10. If the second response is negative ten more squeezes are repeated rapidly and the test subject is again asked whether the saccharin can be tasted.

11. The test conductor will take note of the number of squeezes required to elicit a taste response.

12. If the saccharin is not tasted after 30 squeezes (Step 10), the saccharin fit test cannot be performed on the test subject.

13. If a taste response is elicited, the test subject shall be asked to take note of the taste for reference in the fit test.

14. Correct use of the nebulizer means that approximately 1 cc of liquid is used at a time in the nebulizer body.

15. The nebulizer shall be thoroughly rinsed in water, shaken dry, and refilled at least every four hours.

C. Fit test. 1. The test subject shall don and adjust the respirator without the assistance from any person.

2. The fit test uses the same enclosure described in IIB above.

3. Each test subject shall wear the respirator for a least 10 minutes before starting the fit test.

4. The test subject shall don the enclosure while wearing the respirator selected in section IB above. This respirator shall be properly adjusted and equipped with a particulate filter.

5. The test subject may not eat, drink (except plain water), or chew gum for 15 minutes before the test.

6. A second DeVilbiss Model 40 Inhalation Medication Nebulizer is used to spray the fit test solution into the enclosure. This nebulizer shall be clearly marked to distinguish it from the screening test solution nebulizer.

7. The fit test solution is prepared by adding 83 grams of sodium saccharin to 100 cc of warm water.

8. As before, the test subject shall breathe with mouth open and tongue extended.

9. The nebulizer is inserted into the hole in the front of the enclosure and the fit test solution is sprayed into the enclosure using the same technique as for the taste threshold screening and the same number of squeezes required to elicit a taste response in the screening. (See B8 through B10 above).

10. After generation of the aerosol read the following instructions to the test subject. The test subject shall perform the exercises for one minute each.

i. Breathe normally. ii. Breathe deeply. Be certain breaths are deep and regular. iii. Turn head all the way from one side to the other. Be certain movement is complete. Inhale on each side. Do not bump the respirator against the shoulders. iv. Nod head up-and-down. Be certain motions are complete. Inhale when head is in the full up position (when looking toward the ceiling). Do not to bump the respirator on the chest. v. Talking. Talk aloud and slowly for several minutes. The following paragraph is called the Rainbow Passage. Reading it will result in a wide range of facial movements, and thus be useful to satisfy this requirement. Alternative passages which serve the same purpose may also be used. vi. Jogging in place. vii. Breathe normally.

Rainbow Passage

When the sunlight strikes raindrops in the air, they act like a prism and form a rainbow. The rainbow is a division of white light into many beautiful colors. These take the shape of a long round arch, with its path high above, and its two ends apparently beyond the horizon. There is, according to legend, a boiling pot of gold at one end. People look, but no one ever finds it. When a man looks for something beyond his reach, his friends say he is looking for the pot of gold at the end of the rainbow.

11. At the beginning of each exercise, the aerosol concentration shall be replenished using one-half the number of squeezes as initially described in C9.

12. The test subject shall indicate to the test conductor if at any time during the fit test the taste of saccharin is detected.

13. If the saccharin is detected the fit is deemed unsatisfactory and a different respirator shall be tried.

14. At least two facepieces shall be selected by the IAA test protocol. The test subject shall be given the opportunity to wear them for one week to choose the one which is more comfortable to wear.

15. Successful completion of the test protocol shall allow the use of the half mask tested respirator in contaminated atmospheres up to 10 times the PEL of asbestos. In other words this protocol may be used assign protection factors no higher than ten.

16. The test shall not be conducted if there is any hair growth between the skin and the facepiece sealing surface.

17. If hair growth or apparel interfere with a satisfactory fit, then they shall be altered or removed so as to eliminate interference and allow a satisfactory fit. If a satisfactory fit is still not attained, the test subject must use a positive-pressure respirator such as powered air-purifying respirators, supplied air respirator, or self-contained breathing apparatus.

18. If a test subject exhibits difficulty in breathing during the tests, she or he shall be referred to a physician trained in respirator diseases or pulmonary medicine to determine whether the test subject can wear a respirator while performing her or his duties.

19. Qualitative fit testing shall be repeated at least every six months.

20. In addition, because the sealing of the respirator may be affected, qualitative fit testing shall be repeated immediately when the test subject has a:

(1) Weight change of 20 pounds or more, (2) Significant facial scarring in the area of the facepiece seal, (3) Significant dental changes; i.e.; multiple extractions without prothesis, or acquiring dentures, (4) Reconstructive or cosmetic surgery, or (5) Any other condition that may interfere with facepiece sealing.

D. Recordkeeping. A summary of all test results shall be maintained in each office for 3 years. The summary shall include:

(1) Name of test subject (2) Date of testing. (3) Name of test conductor. (4) Respirators selected (indicate manufacturer, model, size and approval number).(5) Testing agent.

III. Irritant Fume Protocol

A. Respirator selection. Respirators shall be selected as described in section IB above, except that each respirator shall be equipped with a combination of high-efficiency and acid-gas cartridges.

B. Fit test. 1. The test subject shall be allowed to smell a weak concentration of the irritant smoke to familiarize the subject with the characteristic odor.

2. The test subject shall properly don the respirator selected as above, and wear it for at least 10 minutes before starting the fit test.

3. The test conductor shall review this protocol with the test subject before testing.

4. The test subject shall perform the conventional positive pressure and negative pressure fit checks (see ANSI Z88.2 1980). Failure of either check shall be cause to select an alternate respirator.

5. Break both ends of a ventilation smoke tube containing stannic oxychloride, such as the MSA part #5645, or equivalent. Attach a short length of tubing to one end of the smoke tube. Attach the other end of the smoke tube to a low pressure air pump set to deliver 200 milliliters per minute.

6. Advise the test subject that the smoke can be irritating to the eyes and instruct the subject to keep the eyes closed while the test is performed.

7. The test conductor shall direct the stream of irritant smoke from the tube towards the faceseal area of the test subject. The person conducting the test shall begin with the tube at least 12 inches from the facepiece and gradually move to within one inch, moving around the whole perimeter of the mask.

8. The test subject shall be instructed to do the following exercises while the respirator is being challenged by the smoke. Each exercise shall be performed for one minute.

i. Breathe normally. ii. Breathe deeply. Be certain breaths are deep and regular. iii. Turn head all the way from one side to the other. Be certain movement is complete. Inhale on each side. Do not bump the respirator against the shoulders. iv. Nod head up-and-down. Be certain motions are complete and made every second. Inhale when head is in the full up position (looking toward ceiling). Do not bump the respirator against the chest. v. Talking. Talk aloud and slowly for several minutes. The following paragraph is called the Rainbow Passage. Reading it will result in a wide range of facial movements, and thus be useful to satisfy this requirement. Alternative passages which serve the same purpose may also be used.

Rainbow Passage

When the sunlight strikes raindrops in the air, they act like a prism and form a rainbow. The rainbow is a division of white light into many beautiful colors. These take the shape of a long round arch, with its path high above, and its two end apparently beyond the horizon. There is, according to legend, a boiling pot of gold at one end. People look, but no one ever finds it. When a man looks for something beyond his reach, his friends say he is looking for the pot of gold at the end of the rainbow.

vi. Jogging in Place. vii. Breathe normally.

9. The test subject shall indicate to the test conductor if the irritant smoke is detected. If smoke is detected, the test conductor shall stop the test. In this case, the tested respirator is rejected and another respirator shall be selected.

10. Each test subject passing the smoke test (i.e. without detecting the smoke) shall be given a sensitivity check of smoke from the same tube to determine if the test subject reacts to the smoke. Failure to evoke a response shall void the fit test.

11. Steps B4, B9, B10 of this fit test protocol shall be performed in a location with exhaust ventilation sufficient to prevent general contamination of the testing area by the test agents.

12. At least two facepieces shall be selected by the IAA test protocol. The test subject shall be given the opportunity to wear them for one week to choose the one which is more comfortable to wear.

13. Respirators successfully tested by the protocol may be used in contaminated atmospheres up to ten times the PEL of asbestos.

14. The test shall not be conducted if there is any hair growth between the skin and the facepiece sealing surface.

15. If hair growth or apparel interfere with a satisfactory fit, then they shall be altered or removed so as to eliminate interference and allow a satisfactory fit. If a satisfactory fit is still not attained, the test subject must use a positive-pressure respirator such as powered air-purifying respirators, supplied air respirator, or self-contained breathing apparatus.

16. If a test subject exhibits difficulty in breathing during the tests, she or he shall be referred to a physician trained in respirator diseases or pulmonary medicine to determine whether the test subject can wear a respirator while performing her or his duties.

17. Qualitative fit testing shall be repeated at least every six months.

18. In addition, because the sealing of the respirator may be affected, qualitative fit testing shall be repeated immediately when the test subject has a:

(1) Weight change of 20 pounds or more, (2) Significant facial scarring in the area of the facepiece seal, (3) Significant dental changes; i.e.; multiple extractions without prothesis, or acquiring dentures, (4) Reconstructive or cosmetic surgery, or (5) Any other condition that may interfere with facepiece sealing.

 

D. Recordkeeping. A summary of all test results shall be maintained in each office for 3 years. The summary shall include:

(1) Name of test subject (2) Date of testing. (3) Name of test conductor. (4) Respirators selected (indicate manufacturer, model, size and approval number).(5) Testing agent

Quantitative Fit Test Procedures

1. General

a. The method applies to the negative-pressure non-powered air-purifying respirators only.

b. The employer shall assign one individual who shall assume the full responsibility for implementing the respirator quantitative fit test program.

2. Definition

a. "Quantitative Fit Test" means the measurement of the effectiveness of a respirator seal in excluding the ambient atmosphere. The test is performed by dividing the measured concentration of challenge agent in a test chamber by the measured concentration of the challenge agent inside the respirator facepiece when the normal air purifying element has been replaced by an essentially perfect purifying element.

b. "Challenge Agent" means the air contaminant introduced into a test chamber so that its concentration inside and outside the respirator may be compared.

c. "Test Subject" means the person wearing the respirator for quantitative fit testing.

d. "Normal Standing Position" means standing erect and straight with arms down along the sides and looking straight ahead.

e. "Fit Factor" means the ratio of challenge agent concentration outside with respect to the inside of a respirator inlet covering (facepiece or enclosure).

3. Apparatus

a. Instrumentation. Corn oil, sodium chloride or other appropriate aerosol generation, dilution, and measurement systems shall be used for quantitative fit test.

b. Test chamber. The test chamber shall be large enough to permit all test subjects to freely perform all required exercises without distributing the challenge agent concentration or the measurement apparatus. The test chamber shall be equipped and constructed so that the challenge agent is effectively isolated from the ambient air yet uniform in concentration throughout the chamber.

c. When testing air-purifying respirators, the normal filter or cartridge element shall be replaced with a high-efficiency particular filter supplied by the same manufacturer.

d. The sampling instrument shall be selected so that a strip chart record may be made of the test showing the rise and fall of challenge agent concentration with each inspiration and expiration at fit factors of at least 2,000.

e. The combination of substitute air-purifying elements (if any), challenge agent, and challenge agent concentration in the test chamber shall be such that the test subject is not exposed in excess of PEL to the challenge agent at any time during the testing process.

f. The sampling port on the test specimen respirator shall be placed and constructed so that there is no detectable leak around the port, a free air flow is allowed into the sampling line at all times and so there is no interference with the fit or performance of the respirator.

g. The test chamber and test set-up shall permit the person administering the test to observe one test subject inside the chamber during the test.

h. The equipment generating the challenge atmosphere shall maintain the concentration of challenge agent constant within a 10 percent variation for the duration of the test.

i. The time lag (interval between an event and its being recorded on the strip chart) of the instrumentation may not exceed 2 seconds.

j. The tubing for the test chamber atmosphere and for the respirator sampling port shall be the same diameter, length and material. It shall be kept as short as possible. The smallest diameter tubing recommended by the manufacturer shall be used.

k. The exhaust flow from the test chamber shall pass through a high-efficiency filter before release to the room.

l. When sodium chloride aerosol is used, the relative humidity inside the test chamber shall not exceed 50 percent.

4. Procedural Requirements

a. The fitting of half-mask respirators should be started with those having multiple sizes and a variety of interchangeable cartridges and canisters such as the MSA Comfo II-M, Norton M, Survivair M, A-O M, or Scott-M. Use either of the tests outlined below to assure that the facepiece is properly adjusted.

(1) Positive pressure test. With the exhaust port(s) blocked, the negative pressure of slight inhalation should remain constant for several seconds.

(2) Negative pressure test. With the intake port(s) blocked, the negative pressure slight inhalation should remain constant for several seconds.

b. After a facepiece is adjusted, the test subject shall wear the facepiece for at least 5 minutes before conducting a qualitative test by using either of the methods described below and using the exercise regime described in 5.a., b., c., d. and e.

(1) Isoamyl acetate test. When using organic vapor cartridges, the test subject who can smell the odor should be unable to detect the odor of isoamyl acetate squirted into the air near the most vulnerable portions of the facepiece seal. In a location which is separated from the test area, the test subject shall be instructed to close her/his eyes during the test period. A combination cartridge or canister with organic vapor and high-efficiency filters shall be used when available for the particular mask being tested. The test subject shall be given an opportunity to smell the odor of isoamyl acetate before the test is conducted.

(2) Irritant fume test. When using high-efficiency filters, the test subject should be unable to detect the odor of irritant fume (stannic chloride or titanium tetrachloride ventilation smoke tubes) squirted into the air near the most vulnerable portions of the facepiece seal. The test subject shall be instructed to close her/ his eyes during the test period.

c. The test subject may enter the quantitative testing chamber only if she or he has obtained a satisfactory fit as stated in 4.b. of this Appendix.

d. Before the subject enters the test chamber, a reasonably stable challenge agent concentration shall be measured in the test chamber.

e. Immediately after the subject enters the test chamber, the challenge agent concentration inside the respirator shall be measured to ensure that the peak penetration does not exceed 5 percent for a half-mask and 1 percent for a full facepiece.

f. A stable challenge agent concentration shall be obtained prior to the actual start of testing.

1. Respirator restraining straps may not be over-tightened for testing. The straps shall be adjusted by the wearer to give a reasonably comfortable fit typical of normal use.

5. Exercise Regime. Prior to entering the test chamber, the test subject shall be given complete instructions as to her/his part in the test procedures. The test subject shall perform the following exercises, in the order given, for each independent test.

a. Normal Breathing (NB). In the normal standing position, without talking, the subject shall breathe normally for at least one minute.

b. Deep Breathing (DB). In the normal standing position the subject shall do deep breathing for at least one minute pausing so as not to hyperventilate.

c. Turning head side to side (SS). Standing in place the subject shall slowly turn his/her head from side between the extreme positions to each side. The head shall be held at each extreme position for at least 5 seconds. Perform for at least three complete cycles.

d. Moving head up and down (UD). Standing in place, the subject shall slowly move his/her head up and down between the extreme position straight up and the extreme position straight down. The head shall be held at each extreme position for at least 5 seconds. Perform for at least three complete cycles.

e. Reading (R). The subject shall read out slowly and loud so as to be heard clearly by the test conductor or monitor. The test subject shall read the "rainbow passage" at the end of this section.

f. Grimace (G). The test subject shall grimace, smile, frown, and generally contort the face using the facial muscles. Continue for at least 15 seconds.

g. Bend over and touch toes (B). The test subject shall bend at the waist and touch toes and return to upright position. Repeat for at least 30 seconds.

h. Jogging in place (J). The test subject shall perform jog in place for at least 30 seconds.

i. Normal Breathing (NB). Same as exercise a.

Rainbow Passage

When the sunlight strikes raindrops in the air, they act like a prism and form a rainbow. The rainbow is a division of white light into many beautiful colors. These take the shape of a long round arch, with its path high above, and its two ends apparently beyond the horizon. There is, according to legend, a boiling pot of gold at one end. People look, but no one ever finds it. When a man looks for something beyond reach, his friends say he is looking for the pot of gold at the end of the rainbow.

6. The test shall be terminated whenever any single peak penetration exceeds 5 percent for half-masks and 1 percent for full facepieces. The test subject may be refitted and retested. If two the three required tests are terminated, the fit shall be deemed inadequate. (See paragraph 4.h.).

7. Calculation of Fit Factors

a. The fit factor determined by the quantitative fit test equals the average concentration inside the respirator.

b. The average test chamber concentration is the arithmetic average of the test chamber concentration at the beginning and of the end of the test.

c. The average peak concentration of the challenge agent inside the respirator shall be the arithmetic average peak concentrations for each of the nine exercises of the test which are computed as the arithmetic average of the peak concentrations found for each breath during the exercise.

d. The average peak concentration for an exercise may be determined graphically if there is not a great variation in the peak concentrations during a single exercise.

8. Interpretation of Test Results.

The fit factor measured by the quantitative fit testing shall be the lowest of the three protection factors resulting from three independent tests.

9. Other Requirements

a. The test subject shall not be permitted to wear a half-mask or full facepiece mask if the minimum fit factor of 100 or 1,000, respectively, cannot be obtained. If hair growth or apparel interfere with a satisfactory fit, then they shall be altered or removed so as to eliminate interference and allow a satisfactory fit. If a satisfactory fit is still not attained, the test subject must use a positive-pressure respirator such as powered air- purifying respirators, supplied air respirator, or self-contained breathing apparatus.

b. The test shall not be conducted if there is any hair growth between the skin and the facepiece sealing surface.

c. If a test subject exhibits difficulty in breathing during the tests, she or he shall be referred to a physician trained in respirator diseases or pulmonary medicine to determine whether the test subject can wear a respirator while performing her or his duties.

d. The test subject shall be given the opportunity to wear the assigned respirator for one week. If the respirator does not provide a satisfactory fit during actual use, the test subject may request another QNFT which shall be performed immediately.

e. A respirator fit factor card shall be issued to the test subject with the following information:

(1) Name

(2) Date of fit test.

(3) Protection factors obtained through each manufacturer, model and approval number of respirator tested.

(4) Name and signature of the person that conducted the test.

f. Filters used for qualitative or quantitative fit testing shall be replaced weekly, whenever increased breathing resistance is encountered, or when the test agent has altered the integrity of the filter media.

Organic vapor cartridges/canisters shall be replaced daily or sooner if there is any indication of breakthrough by the test agent.

10. In addition, because the sealing of the respirator may be affected, quantitative fit testing shall be repeated immediately when the test subject has a:

(1) Weight change of 20 pounds or more, (2) Significant facial scarring in the area of the facepiece seal, (3) Significant dental changes; i.e.; multiple extractions without prothesis, or acquiring dentures, (4) Reconstructive or cosmetic surgery, or (5) Any other condition that may interfere with facepiece sealing.

11. Recordkeeping

A summary of all test results shall be maintained in for 3 years. The summary shall include:

(1) Name of test subject (2) Date of testing. (3) Name of the test conductor. (4) Fit factors obtained from every respirator tested (indicate manufacturer, model, size and approval number).

Appendix D to 1915.1001 -- Medical Questionnaires. Mandatory

This mandatory appendix contains the medical questionnaires that must be administered to all employees who are exposed to asbestos, tremolite, anthophyllite, actinolite, or a combination of these minerals above the permissible exposure limit (0.1 f/cc), and who will therefore be included in their employer's medical surveillance program. Part 1 of the appendix contains the Initial Medical Questionnaire, which must be obtained for all new hires who will be covered by the medical surveillance requirements. Part 2 includes the abbreviated Periodical Medical Questionnaire, which must be administered to all employees who are provided periodic medical examinations under the medical surveillance provisions of the standard.

                              Part 1
                   INITIAL MEDICAL QUESTIONNAIRE

1.  NAME ________________________________________________________________

2.  SOCIAL SECURITY NUMBER # ____________________________________________

3.  CLOCK NUMBER ________________________________________________________

4.  PRESENT OCCUPATION __________________________________________________

5.  PLANT _______________________________________________________________

6.  ADDRESS _____________________________________________________________

7.  _____________________________________________________________________
        (Zip Code)

8.  TELEPHONE NUMBER ____________________________________________________

9.  INTERVIEWER _________________________________________________________

10. DATE ________________________________________________________________

11. Date of Birth _______________________________________________________
                  Month      Day     Year

12. Place of Birth ______________________________________________________

13. Sex                                 1. Male    ___
                                        2. Female  ___

14. What is your marital status?        1. Single  ___  4. Separated/
                                        2. Married ___      Divorced ___
                                        3. Widowed ___

15. Race                                1. White ___   4. Hispanic ___

                                        2. Black ___   5. Indian   ___

                                        3. Asian ___   6. Other    ___


16.  What is the highest grade completed in school? _____________________

     (For example 12 years is completion of high school)

OCCUPATIONAL HISTORY

17A.  Have you ever worked full time (30 hours     1. Yes ___  2. No ___
      per week or more) for 6 months or more?

      IF YES TO 17A:

  B.  Have you ever worked for a year or more in   1. Yes ___  2. No ___
      any dusty job?                               3. Does Not Apply ___

      Specify job/industry _______________ Total Years Worked __________

      Was dust exposure: 1. Mild  ____  2. Moderate ____  3. Severe ____

  C.  Have you ever been exposed to gas or         1. Yes ___  2. No ___
      chemical fumes in your work?
      Specify job/industry ______________________ Total Years Worked ___

      Was exposure :     1. Mild  ____  2. Moderate ____  3. Severe ____

  D.  What has been your usual occupation or job  --  the one you have
      worked at the longest?

      1. Job occupation ________________________________________________

      2. Number of years employed in this occupation ___________________

      3. Position/job title ____________________________________________

      4. Business, field or industry ___________________________________
(Record on lines the years in which you have worked in any of these
industries, e.g. 1960-1969)

Have you ever worked:                                 YES        NO

  E.   In a mine? .........................          _____      _____

  F.   In a quarry? .......................          _____      _____

  G.   In a foundry? ......................          _____      _____

  H.   In a pottery? ......................          _____      _____

  I.   In a cotton, flax or hemp mill? ....          _____      _____

  J.   With asbestos? .....................          _____      _____

18.  PAST MEDICAL HISTORY
                                                      YES        NO

  A. Do you consider yourself to be in good health?  _____      _____

         If "NO" state reason __________________________________________

  B. Have you any defect of vision? ...............  _____      _____

         If "YES" state nature of defect _______________________________

  C. Have you any hearing defect? .................  _____      _____

         If "YES" state nature of defect ______________________________

  D. Are you suffering from or have you ever suffered from:
                                                      YES        NO
     a.  Epilepsy (or fits, seizures, convulsions)?  _____      _____

     b.  Rheumatic fever?                            _____      _____

     c.  Kidney disease?                             _____      _____

     d.  Bladder disease?                            _____      _____

     e.  Diabetes?                                   _____      _____

     f.  Jaundice?                                   _____      _____

19.  CHEST COLDS AND CHEST ILLNESSES

19A. If you get a cold, does it "usually" go to your
     chest?  (Usually means more than 1/2 the time)
                            1. Yes ___  2. No ___  3. Don't get colds ___

20A. During the past 3 years, have you had any chest illnesses
     that have kept you off work, indoors at home, or in bed?
                            1. Yes ___  2. No ___
        IF YES TO 20A:
  B. Did you produce phlegm with any of these chest illnesses?
                            1. Yes ___  2. No ___  3. Does Not Apply ___

  C. In the last 3 years, how many such illnesses with (increased)
     phlegm did you have which lasted a week or more?
           Number of illnesses ___     No such illnesses   ___

21.  Did you have any lung trouble before the age of 16?
                            1. Yes ___  2. No ___

22.  Have you ever had any of the following?

     1A.  Attacks of bronchitis?                     1. Yes ___  2. No ___

          IF YES TO 1A:
      B. Was it confirmed by a doctor?               1. Yes ___  2. No ___
                                                     3. Does Not Apply ___

      C. At what age was your first attack?             Age in Years   ___
                                                        Does Not Apply ___

     2A. Pneumonia (include bronchopneumonia)?       1. Yes ___  2. No ___

         IF YES TO 2A:
      B. Was it confirmed by a doctor?               1. Yes ___  2. No ___
                                                     3. Does Not Apply ___

      C. At what age did you first have it?             Age in Years   ___
                                                        Does Not Apply ___

     3A. Hay Fever?                                  1. Yes ___  2. No ___
         IF YES TO 3A:
      B. Was it confirmed by a doctor?               1. Yes ___  2. No ___
                                                     3. Does Not Apply ___

      C. At what age did it start?                      Age in Years   ___
                                                        Does Not Apply ___


23A. Have you ever had chronic bronchitis?           1. Yes ___  2. No ___

         IF YES TO 23A:
  B. Do you still have it?                           1. Yes ___  2. No ___
                                                     3. Does Not Apply ___

  C.  Was it confirmed by a doctor?                  1. Yes ___  2. No ___
                                                     3. Does Not Apply ___

  D. At what age did it start?                          Age in Years   ___
                                                        Does Not Apply ___

24A. Have you ever had emphysema?                    1. Yes ___  2. No ___
          IF YES TO 24A:
  B. Do you still have it?                           1. Yes ___  2. No ___
                                                     3. Does Not Apply ___

  C. Was it confirmed by a doctor?                   1. Yes ___  2. No ___
                                                     3. Does Not Apply ___

  D. At what age did it start?                          Age in Years   ___
                                                        Does Not Apply ___

25A. Have you ever had asthma?                       1. Yes ___  2. No ___
          IF YES TO 25A:

  B. Do you still have it?                           1. Yes ___  2. No ___
                                                     3. Does Not Apply ___

  C. Was it confirmed by a doctor?                   1. Yes ___  2. No ___
                                                     3. Does Not Apply ___

  D. At what age did it start?                          Age in Years   ___
                                                        Does Not Apply ___
  E. If you no longer have it, at what age did it stop?
                                                        Age stopped    ___
                                                        Does Not Apply ___

26.  Have you ever had:

  A. Any other chest illness?                        1. Yes ___  2. No ___

        If yes, please specify ___________________________________________

  B. Any chest operations?                           1. Yes ___  2. No ___

        If yes, please specify ___________________________________________

  C. Any chest injuries?                             1. Yes ___  2. No ___

        If yes, please specify ___________________________________________

27A. Has a doctor ever told you that you had heart trouble?
                                                     1. Yes ___  2. No ___

         IF YES TO 27A:
  B. Have you ever had treatment for heart trouble in the past 10 years?
                                                     1. Yes ___  2. No ___
                                                     3. Does Not Apply ___

28A. Has a doctor told you that you had high blood pressure?
                                                     1. Yes ___  2. No ___

         IF YES TO 28A:
  B. Have you had any treatment for high blood pressure (hypertension)
     in the past 10 years?
                                                     1. Yes ___  2. No ___
                                                     3. Does Not Apply ___

29.  When did you last have your chest X-rayed?
            (Year) ___  ___  ___  ___

30.  Where did you last have your chest X-rayed (if known)?
     _____________________________________________________________________

     What was the outcome? _______________________________________________

FAMILY HISTORY

31.  Were either of your natural parents ever told by a doctor that they
     had a chronic lung condition such as:

                             FATHER                     MOTHER
                    1. Yes  2. No  3. Don't    1. Yes  2. No  3. Don't
                                      know                       know

  A. Chronic Bronchitis?
                       ___    ___     ___         ___     ___    ___

  B. Emphysema?        ___    ___     ___         ___     ___    ___

  C. Asthma?           ___    ___     ___         ___     ___    ___

  D. Lung cancer?      ___    ___     ___         ___     ___    ___

  E. Other chest conditions?
                       ___    ___     ___         ___     ___    ___

  F. Is parent currently alive?
                       ___    ___     ___         ___     ___    ___

  G. Please Specify    ___ Age if Living          ___ Age if Living
                       ___ Age at Death           ___ Age at Death
                       ___ Don't Know             ___ Don't Know

  H. Please specify cause of death
     ____________________________________     __________________________

COUGH

32A. Do you usually have a cough? (Count a cough with first smoke or on
     first going out of doors.  Exclude clearing of throat.) (If no,
     skip to question 32C.)
                                                     1. Yes ___  2. No ___
  B. Do you usually cough as much as 4 to 6 times a day 4 or more days
     out of the week?
                                                     1. Yes ___  2. No ___

  C. Do you usually cough at all on getting up or first thing in the
     morning?
                                                     1. Yes ___  2. No ___

  D. Do you usually cough at all during the rest of the day or at night?
                                                     1. Yes ___  2. No ___

IF YES TO ANY OF ABOVE (32A, B, C, OR D,), ANSWER THE FOLLOWING.  IF NO
TO ALL, CHECK "DOES NOT APPLY" AND SKIP TO NEXT PAGE

  E. Do you usually cough like this on most days for 3 consecutive
     months or more during the year?
                                                     1. Yes ___  2. No ___
                                                     3. Does not apply ___

  F. For how many years have you had the cough?        Number of years ___
                                                       Does not apply  ___

33A. Do you usually bring up phlegm from your chest?
     (Count phlegm with the first smoke or on first going out of doors.
     Exclude phlegm from the nose.  Count swallowed phlegm.)  (If no,
     skip to 33C)
                                                     1. Yes ___  2. No ___

  B. Do you usually bring up phlegm like this as much as twice a day 4
     or more days out of the week?
                                                     1. Yes ___  2. No ___

  C. Do you usually bring up phlegm at all on getting up or first thing
     in the morning?
                                                     1. Yes ___  2. No ___

  D. Do you usually bring up phlegm at all on during the rest of the day
     or at night?
                                                     1. Yes ___  2. No ___

IF YES TO ANY OF THE ABOVE (33A, B, C, OR D), ANSWER THE FOLLOWING:

IF NO TO ALL, CHECK "DOES NOT APPLY" AND SKIP TO 34A

  E. Do you bring up phlegm like this on most days for 3 consecutive
     months or more during the year?

                                                     1. Yes ___  2. No ___
                                                     3. Does not apply ___

  F. For how many years have you had trouble with phlegm?
                                                       Number of years ___
                                                       Does not apply  ___

EPISODES OF COUGH AND PHLEGM

34A. Have you had periods or episodes of (increased*) cough and phlegm
     lasting for 3 weeks or more each year?
     *(For persons who usually have cough and/or phlegm)
                                                     1. Yes ___  2. No ___

     IF YES TO 34A
  B. For how long have you had at least 1 such episode per year?
                                                       Number of years ___
                                                       Does not apply  ___

WHEEZING

35A. Does your chest ever sound wheezy or whistling
              1. When you have a cold?               1. Yes ___  2. No ___

              2. Occasionally apart from colds?      1. Yes ___  2. No ___

              3. Most days or nights?                1. Yes ___  2. No ___

         IF YES TO 1, 2, or 3 in 35A
  B. For how many years has this been present?
                                                       Number of years ___
                                                       Does not apply  ___

36A. Have you ever had an attack of wheezing that has made you feel short
     of breath?

                                                     1. Yes ___  2. No ___
         IF YES TO 36A
  B. How old were you when you had your first such attack?
                                                       Age in years   ___
                                                       Does not apply ___

  C. Have you had 2 or more such episodes?
                                                     1. Yes ___  2. No ___
                                                     3. Does not apply ___

  D. Have you ever required medicine or treatment for the(se) attack(s)?

                                                     1. Yes ___  2. No ___
                                                     3. Does not apply ___

BREATHLESSNESS

37.  If disabled from walking by any condition other than heart or lung
     disease, please describe and proceed to question 39A.

     Nature of condition(s) ______________________________________________
     _____________________________________________________________________

38A. Are you troubled by shortness of breath when hurrying on the level
     or walking up a  slight hill?
                                                     1. Yes ___  2. No ___
     IF YES TO 38A

  B. Do you have to walk slower than people of your age on the level
     because of breathlessness?
                                                     1. Yes ___  2. No ___
                                                     3. Does not apply ___

  C. Do you ever have to stop for breath when walking at your own pace
     on the level?
                                                     1. Yes ___  2. No ___
                                                     3. Does not apply ___

  D. Do you ever have to stop for breath after walking about 100 yards
     (or after a few minutes) on the level?
                                                     1. Yes ___  2. No ___
                                                     3. Does not apply ___

  E. Are you too breathless to leave the house or breathless on dressing
     or climbing one flight of stairs?
                                                     1. Yes ___  2. No ___
                                                     3. Does not apply ___

TOBACCO SMOKING

39A. Have you ever smoked cigarettes?  (No means less than 20 packs of
     cigarettes or 12 oz. of tobacco in a lifetime or less than 1
     cigarette a day for 1 year.)
                                                     1. Yes ___  2. No ___

     IF YES TO 39A

  B. Do you now smoke cigarettes (as of one month ago)
                                                     1. Yes ___  2. No ___
                                                     3. Does not apply ___

  C. How old were you when you first started regular cigarette smoking?
                                                        Age in years   ___
                                                        Does not apply ___

  D. If you have stopped smoking cigarettes completely, how old were you
     when you stopped?
                                                Age stopped            ___
                                                Check if still smoking ___
                                                Does not apply         ___

  E. How many cigarettes do you smoke per day now?
                                                Cigarettes per day     ___
                                                Does not apply         ___

  F. On the average of the entire time you smoked, how many cigarettes did
     you smoke per day?
                                                Cigarettes per day     ___
                                                Does not apply         ___

  G. Do or did you inhale the cigarette smoke?
                                                1. Does not apply      ___
                                                2. Not at all          ___
                                                3. Slightly            ___
                                                4. Moderately          ___
                                                5. Deeply              ___

40A. Have you ever smoked a pipe regularly?
     (Yes means more than 12 oz. of tobacco in a lifetime.)
                                                     1. Yes ___  2. No ___

     IF YES TO 40A:
FOR PERSONS WHO HAVE EVER SMOKED A PIPE

  B. 1. How old were you when you started to smoke a pipe regularly?
                                                                   Age ___

     2. If you have stopped smoking a pipe completely, how old were you
        when you stopped?
                                          Age stopped                  ___
                                          Check if still smoking pipe  ___
                                          Does not apply               ___

   C. On the average over the entire time you smoked a pipe, how much pipe
      tobacco did you smoke per week?
                                                          ___ oz. per week
        (a standard pouch of tobacco contains 1 1/2 oz.)
                                                        ___ Does not apply

   D. How much pipe tobacco are you smoking now?
                                         oz. per week                  ___
                                         Not currently smoking a pipe  ___

   E. Do you or did you inhale the pipe smoke?
                                                     1. Never smoked   ___
                                                     2. Not at all     ___
                                                     3. Slightly       ___
                                                     4. Moderately     ___
                                                     5. Deeply         ___

41A. Have you ever smoked cigars regularly?
                                                     1. Yes ___  2. No ___
     (Yes means more than 1 cigar a week for a year)

     IF YES TO 41A

FOR PERSONS WHO HAVE EVER SMOKED A CIGARS

  B. 1. How old were you when you started           Age ___
        smoking cigars regularly?

     2. If you have stopped smoking cigars          Age stopped       ___
        completely, how old were you when           Check if still
        you stopped.                                smoking cigars    ___
                                                    Does not apply    ___

  C. On the average over the entire time you        Cigars per week   ___
     smoked cigars, how many cigars did you         Does not apply    ___
     smoke per week?

  D. How many cigars are you smoking per week       Cigars per week   ___
     now?                                           Check if not
                                                    smoking cigars
                                                    currently         ___

  E. Do or did you inhale the cigar smoke?       1. Never smoked      ___
                                                 2. Not at all        ___
                                                 3. Slightly          ___
                                                 4. Moderately        ___
                                                 5. Deeply            ___

Signature ____________________________   Date _____________________



                                Part 2
                    PERIODIC MEDICAL QUESTIONNAIRE

1.   NAME _______________________________________________________________

2.   SOCIAL SECURITY #       ___  ___  ___  ___  ___  ___  ___    ___  ___

3.   CLOCK NUMBER                        ___  ___  ___  ___  ___  ___  ___

4.   PRESENT OCCUPATION __________________________________________________

5.   PLANT ______________________________________________________________

6.   ADDRESS ____________________________________________________________

7.   ____________________________________________________________________
                                                         (Zip Code)

8.   TELEPHONE NUMBER ___________________________________________________

9.   INTERVIEWER  _______________________________________________________

10.  DATE ___________________________  ___   ___   ___   ___     ___  ___

11.  What is your marital status?      1. Single  ___   4. Separated/.
                                       2. Married ___      Divorced ___
                                       3. Widowed ___

12.  OCCUPATIONAL HISTORY

12A. In the past year, did you work    1. Yes ___       2. No ___
     full time (30 hours per week
     or more) for 6 months or more?

     IF YES TO 12A:

12B. In the past year, did you work    1. Yes ___       2. No ___
     in a dusty job?                   3. Does not Apply ___

12C. Was dust exposure:     1. Mild ___   2. Moderate ___  3. Severe ___

12D. In the past year, were you        1. Yes ___       2. No ___
     exposed to gas or chemical
     fumes in your work?

12E. Was exposure:          1. Mild ___   2. Moderate ___  3. Severe ___

12F. In the past year,
     what was your:         1. Job/occupation? _________________________
                            2. Position/job title? _____________________

13.  RECENT MEDICAL HISTORY

13A. Do you consider yourself to
     be in good health?                Yes  ___        No ___

     If NO, state reason ______________________________________________

13B. In the past year, have you
     developed:                                        Yes     No
                                    Epilepsy?          ___    ___
                                    Rheumatic fever?   ___    ___
                                    Kidney disease?    ___    ___
                                    Bladder disease?   ___    ___
                                    Diabetes?          ___    ___
                                    Jaundice?          ___    ___
                                    Cancer?            ___    ___

14.  CHEST COLDS AND CHEST ILLNESSES

14A. If you get a cold, does it "usually" go to your chest?
     (usually means more than 1/2 the time)
                                                  1. Yes ___   2. No ___
                                                  3. Don't get colds ___

15A. During the past year, have you had
     any chest illnesses that have kept you       1. Yes ___   2. No ___
     off work, indoors at home, or in bed?        3. Does Not Apply  ___

     IF YES TO 15A:

15B. Did you produce phlegm with any              1. Yes ___   2. No ___
     of these chest illnesses?                    3. Does Not Apply  ___

15C. In the past year, how many such              Number of illnesses ___
     illnesses with (increased) phlegm            No such illnesses   ___
     did you have which lasted a week
     or more?

16.  RESPIRATORY SYSTEM

     In the past year have you had:

                         Yes or No       Further Comment on Positive
                                                  Answers
     Asthma                _____

     Bronchitis            _____

     Hay Fever             _____

     Other Allergies       _____


                         Yes or No       Further Comment on Positive
                                                  Answers
     Pneumonia             _____

     Tuberculosis          _____

     Chest Surgery         _____

     Other Lung Problems   _____

     Heart Disease         _____

     Do you have:

                         Yes or No       Further Comment on Positive
                                                  Answers

     Frequent colds        _____

     Chronic cough         _____

     Shortness of breath
     when walking or
     climbing one flight
     or stairs             _____

     Do you:

     Wheeze                _____

     Cough up phlegm       _____

     Smoke cigarettes      _____   Packs per day ____  How many years ___


Date __________________    Signature ____________________________________

Appendix E to 1915.1001 -- Interpretation and Classification of Chest Roentgenograms. Mandatory

(a) Chest roentgenograms shall be interpreted and classified in accordance with a professionally accepted classification system and recorded on a Roentgenographic Interpretation Form. *Form CSD/NIOSH (M) 2.8.

(b) Roentgenograms shall be interpreted and classified only by a B-reader, a board eligible/certified radiologist, or an experienced physician with known expertise in pneumoconioses.

(c) All interpreters, whenever interpreting chest roentgenograms made under this section, shall have immediately available for reference a complete set of the ILO-U/C International Classification of Radiographs for Pneumoconioses, 1980.

Appendix F to 1915.1001 -- Work Practices and Engineering Controls for Class I Asbestos Operations Non-Mandatory

This is a non-mandatory appendix to the asbestos standards for construction and for shipyards. It describes criteria and procedures for erecting and using negative pressure enclosures for Class I Asbestos Work, when NPEs are used as an allowable control method to comply with paragraph (g)(5)(i) of this section. Many small and variable details are involved in the erection of a negative pressure enclosure. OSHA and most participants in the rulemaking agreed that only the major, more performance oriented criteria should be made mandatory. These criteria are set out in paragraph (g) of this section. In addition, this appendix includes these mandatory specifications and procedures in its guidelines in order to make this appendix coherent and helpful. The mandatory nature of the criteria which appear in the regulatory text is not changed because they are included in this "non-mandatory" appendix. Similarly, the additional criteria and procedures included as guidelines in the appendix, do not become mandatory because mandatory criteria are also included in these comprehensive guidelines.

In addition, none of the criteria, both mandatory and recommended, are meant to specify or imply the need for use of patented or licensed methods or equipment. Recommended specifications included in this attachment should not discourage the use of creative alternatives which can be shown to reliably achieve the objectives of negative-pressure enclosures.

Requirements included in this appendix, cover general provisions to be followed in all asbestos jobs, provisions which must be followed for all Class I asbestos jobs, and provisions governing the construction and testing of negative pressure enclosures. The first category includes the requirement for use of wet methods, HEPA vacuums, and immediate bagging of waste; Class I work must conform to the following provisions:

* oversight by competent person * use of critical barriers over all openings to work area * isolation of HVAC systems * use of impermeable dropcloths and coverage of all objects within regulated areas

In addition, more specific requirements for NPEs include:

* maintenance of -0.02 inches water gauge within enclosure * manometric measurements * air movement away from employees performing removal work * smoke testing or equivalent for detection of leaks and air direction * deactivation of electrical circuits, if not provided with ground-fault circuit interrupters.

Planning the Project

The standard requires that an exposure assessment be conducted before the asbestos job is begun Sec. 1915.1001(f)(1). Information needed for that assessment, includes data relating to prior similar jobs, as applied to the specific variables of the current job. The information needed to conduct the assessment will be useful in planning the project, and in complying with any reporting requirements under this standard, when significant changes are being made to a control system listed in the standard, [see paragraph (k) of this section], as well as those of USEPA (40 CFR Part 61, subpart M). Thus, although the standard does not explicitly require the preparation of a written asbestos removal plan, the usual constituents of such a plan, i.e., a description of the enclosure, the equipment, and the procedures to be used throughout the project, must be determined before the enclosure can be erected. The following information should be included in the planning of the system:

A physical description of the work area;

A description of the approximate amount of material to be removed;

A schedule for turning off and sealing existing ventilation systems;

Personnel hygiene procedures;

A description of personal protective equipment and clothing to worn by employees;

A description of the local exhaust ventilation systems to be used and how they are to be tested;

A description of work practices to be observed by employees;

An air monitoring plan;

A description of the method to be used to transport waste material; and

The location of the dump site.

Materials and Equipment Necessary for Asbestos Removal

Although individual asbestos removal projects vary in terms of the equipment required to accomplish the removal of the materials, some equipment and materials are common to most asbestos removal operations.

Plastic sheeting used to protect horizontal surfaces, seal HVAC openings or to seal vertical openings and ceilings should have a minimum thickness of 6 mils. Tape or other adhesive used to attach plastic sheeting should be of sufficient adhesive strength to support the weight of the material plus all stresses encountered during the entire duration of the project without becoming detached from the surface.

Other equipment and materials which should be available at the beginning of each project are:

-- HEPA Filtered Vacuum is essential for cleaning the work area after the asbestos has been removed. It should have a long hose capable of reaching out-of-the-way places, such as areas above ceiling tiles, behind pipes, etc.

-- Portable air ventilation systems installed to provide the negative air pressure and air removal from the enclosure must be equipped with a HEPA filter. The number and capacity of units required to ventilate an enclosure depend on the size of the area to be ventilated. The filters for these systems should be designed in such a manner that they can be replaced when the air flow volume is reduced by the build-up of dust in the filtration material. Pressure monitoring devices with alarms and strip chart recorders attached to each system to indicate the pressure differential and the loss due to dust buildup on the filter are recommended.

-- Water sprayers should be used to keep the asbestos material as saturated as possible during removal; the sprayers will provide a fine mist that minimizes the impact of the spray on the material.

-- Water used to saturate the asbestos containing material can be amended by adding at least 15 milliliters (1/4 ounce) of wetting agent in 1 liter (1 pint) of water. An example of a wetting agent is a 50/50 mixture of polyoxyethylene ether and polyoxyethylene polyglycol ester.

-- Backup power supplies are recommended, especially for ventilation systems.

-- Shower and bath water should be with mixed hot and cold water faucets. Water that has been used to clean personnel or equipment should either be filtered or be collected and discarded as asbestos waste. Soap and shampoo should be provided to aid in removing dust from the workers' skin and hair.

-- See paragraphs (h) and (i) of this section for appropriate respiratory protection and protective clothing. -- See paragraph (k) of this section for required signs and labels.

Preparing the Work Area

Disabling HVAC Systems: The power to the heating, ventilation, and air conditioning systems that service the restricted area must be deactivated and locked off. All ducts, grills, access ports, windows and vents must be sealed off with two layers of plastic to prevent entrainment of contaminated air.

Operating HVAC Systems in the Restricted Area: If components of a HVAC system located in the restricted area are connected to a system that will service another zone during the project, the portion of the duct in the restricted area must be sealed and pressurized. Necessary precautions include caulking the duct joints, covering all cracks and openings with two layers of sheeting, and pressurizing the duct throughout the duration of the project by restricting the return air flow. The power to the fan supplying the positive pressure should be locked "on" to prevent pressure loss.

Sealing Elevators: If an elevator shaft is located in the restricted area, it should be either shut down or isolated by sealing with two layers of plastic sheeting. The sheeting should provide enough slack to accommodate the pressure changes in the shaft without breaking the air-tight seal.

Removing Mobile Objects: All movable objects should be cleaned and removed from the work area before an enclosure is constructed unless moving the objects creates a hazard. Mobile objects will be assumed to be contaminated and should be either cleaned with amended water and a HEPA vacuum and then removed from the area or wrapped and then disposed of as hazardous waste.

Cleaning and Sealing Surfaces: After cleaning with water and a HEPA vacuum, surfaces of stationary objects should be covered with two layers of plastic sheeting. The sheeting should be secured with duct tape or an equivalent method to provide a tight seal around the object.

Bagging Waste: In addition to the requirement for immediate bagging of waste for disposal, it is further recommended that the waste material be double-bagged and sealed in plastic bags designed for asbestos disposal. The bags should be stored in a waste storage area that can be controlled by the workers conducting the removal. Filters removed from air handling units and rubbish removed from the area are to be bagged and handled as hazardous waste.

Constructing the Enclosure

The enclosure should be constructed to provide an air-tight seal around ducts and openings into existing ventilation systems and around penetrations for electrical conduits, telephone wires, water lines, drain pipes, etc. Enclosures should be both airtight and watertight except for those openings designed to provide entry and/ or air flow control.

Size: An enclosure should be the minimum volume to encompass all of the working surfaces yet allow unencumbered movement by the worker(s), provide unrestricted air flow past the worker(s), and ensure walking surfaces can be kept free of tripping hazards.

Shape: The enclosure may be any shape that optimizes the flow of ventilation air past the worker(s).

Structural Integrity: The walls, ceilings and floors must be supported in such a manner that portions of the enclosure will not fall down during normal use.

Openings: It is not necessary that the structure be airtight; openings may be designed to direct air flow. Such openings should be located at a distance from active removal operations. They should be designed to draw air into the enclosure under all anticipated circumstances. In the event that negative pressure is lost, they should be fitted with either HEPA filters to trap dust or automatic trap doors that prevent dust from escaping the enclosure. Openings for exits should be controlled by an airlock or a vestibule.

Barrier Supports: Frames should be constructed to support all unsupported spans of sheeting.

Sheeting: Walls, barriers, ceilings, and floors should be lined with two layers of plastic sheeting having a thickness of at least 6 mil.

Seams: Seams in the sheeting material should be minimized to reduce the possibilities of accidental rips and tears in the adhesive or connections. All seams in the sheeting should overlap, be staggered and not be located at corners or wall-to- floor joints. Areas Within an Enclosure: Each enclosure consists of a work area, a decontamination area, and waste storage area. The work area where the asbestos removal operations occur should be separated from both the waste storage area and the contamination control area by physical curtains, doors, and/or airflow patterns that force any airborne contamination back into the work area.

See paragraph (j) of Sec. 1915.1001 for requirements for hygiene facilities.

During egress from the work area, each worker should step into the equipment room, clean tools and equipment, and remove gross contamination from clothing by wet cleaning and HEPA vacuuming. Before entering the shower area, foot coverings, head coverings, hand coverings, and coveralls are removed and placed in impervious bags for disposal or cleaning. Airline connections from airline respirators with HEPA disconnects and power cables from powered air- purifying respirators (PAPRs) will be disconnected just prior to entering the shower room.

Establishing Negative Pressure Within the Enclosure

Negative Pressure: Air is to be drawn into the enclosure under all anticipated conditions and exhausted through a HEPA filter for 24 hours a day during the entire duration of the project.

Air Flow Tests: Air flow patterns will be checked before removal operations begin, at least once per operating shift and any time there is a question regarding the integrity of the enclosure. The primary test for air flow is to trace air currents with smoke tubes or other visual methods. Flow checks are made at each opening and at each doorway to demonstrate that air is being drawn into the enclosure and at each worker's position to show that air is being drawn away from the breathing zone.

Monitoring Pressure Within the Enclosure: After the initial air flow patterns have been checked, the static pressure must be monitored within the enclosure. Monitoring may be made using manometers, pressure gauges, or combinations of these devices. It is recommended that they be attached to alarms and strip chart recorders at points identified by the design engineer.

Corrective Actions: If the manometers or pressure gauges demonstrate a reduction in pressure differential below the required level, work should cease and the reason for the change investigated and appropriate changes made. The air flow patterns should be retested before work begins again.

Pressure Differential: The design parameters for static pressure differentials between the inside and outside of enclosures typically range from 0.02 to 0.10 inches of water gauge, depending on conditions. All zones inside the enclosure must have less pressure than the ambient pressure outside of the enclosure (-0.02 inches water gauge differential). Design specifications for the differential vary according to the size, configuration, and shape of the enclosure as well as ambient and mechanical air pressure conditions around the enclosure.

Air Flow Patterns: The flow of air past each worker shall be enhanced by positioning the intakes and exhaust ports to remove contaminated air from the worker's breathing zone, by positioning HEPA vacuum cleaners to draw air from the worker's breathing zone, by forcing relatively uncontaminated air past the worker toward an exhaust port, or by using a combination of methods to reduce the worker's exposure.

Air Handling Unit Exhaust: The exhaust plume from air handling units should be located away from adjacent personnel and intakes for HVAC systems.

Air Flow Volume: The air flow volume (cubic meters per minute) exhausted (removed) from the workplace must exceed the amount of makeup air supplied to the enclosure. The rate of air exhausted from the enclosure should be designed to maintain a negative pressure in the enclosure and air movement past each worker. The volume of air flow removed from the enclosure should replace the volume of the container at every 5 to 15 minutes. Air flow volume will need to be relatively high for large enclosures, enclosures with awkward shapes, enclosures with multiple openings, and operations employing several workers in the enclosure.

Air Flow Velocity: At each opening, the air flow velocity must visibly "drag" air into the enclosure. The velocity of air flow within the enclosure must be adequate to remove airborne contamination from each worker's breathing zone without disturbing the asbestos-containing material on surfaces.

Airlocks: Airlocks are mechanisms on doors and curtains that control the air flow patterns in the doorways. If air flow occurs, the patterns through doorways must be such that the air flows toward the inside of the enclosure. Sometimes vestibules, double doors, or double curtains are used to prevent air movement through the doorways. To use a vestibule, a worker enters a chamber by opening the door or curtain and then closing the entry before opening the exit door or curtain.

Airlocks should be located between the equipment room and shower room, between the shower room and the clean room, and between the waste storage area and the outside of the enclosure. The air flow between adjacent rooms must be checked using smoke tubes or other visual tests to ensure the flow patterns draw air toward the work area without producing eddies.

Monitoring for Airborne Concentrations

In addition to the breathing zone samples taken as outlined in paragraph (f) of Sec. 1915.1001 , samples of air should be taken to demonstrate the integrity of the enclosure, the cleanliness of the clean room and shower area, and the effectiveness of the HEPA filter. If the clean room is shown to be contaminated, the room must be relocated to an uncontaminated area.

Samples taken near the exhaust of portable ventilation systems must be done with care.

General Work Practices

Preventing dust dispersion is the primary means of controlling the spread of asbestos within the enclosure. Whenever practical, the point of removal should be isolated, enclosed, covered, or shielded from the workers in the area. Waste asbestos containing materials must be bagged during or immediately after removal; the material must remain saturated until the waste container is sealed.

Waste material with sharp points or corners must be placed in hard air-tight containers rather than bags.

Whenever possible, large components should be sealed in plastic sheeting and removed intact.

Bags or containers of waste will be moved to the waste holding area, washed, and wrapped in a bag with the appropriate labels.

Cleaning the Work Area

Surfaces within the work area should be kept free of visible dust and debris to the extent feasible. Whenever visible dust appears on surfaces, the surfaces within the enclosure must be cleaned by wiping with a wet sponge, brush, or cloth and then vacuumed with a HEPA vacuum.

All surfaces within the enclosure should be cleaned before the exhaust ventilation system is deactivated and the enclosure is disassembled. An approved encapsulate may be sprayed onto areas after the visible dust has been removed.

Appendix G to 1915.1001 [Reserved]

Appendix H to Sec. 1915.1001 -- Substance Technical Information for Asbestos. Non-Mandatory

I. Substance Identification

A. Substance: "Asbestos" is the name of a class of magnesium-silicate minerals that occur in fibrous form. Minerals that are included in this group are chrysotile, crocidolite, amosite, anthophyllite asbestos, tremolite asbestos, and actinolite asbestos.

B. Asbestos is and was used in the manufacture of heat-resistant clothing, automotive brake and clutch linings, and a variety of building materials including floor tiles, roofing felts, ceiling tiles, asbestos-cement pipe and sheet, and fire-resistant drywall. Asbestos is also present in pipe and boiler insulation materials and in sprayed-on materials located on beams, in crawlspaces, and between walls.

C. The potential for an asbestos-containing product to release breathable fibers depends largely on its degree of friability. Friable means that the material can be crumbled with hand pressure and is therefore likely to emit fibers. The fibrous fluffy sprayed- on materials used for fireproofing, insulation, or sound proofing are considered to be friable, and they readily release airborne fibers if disturbed. Materials such as vinyl-asbestos floor tile or roofing felt are considered non-friable if intact and generally do not emit airborne fibers unless subjected to sanding, sawing and other aggressive operations. Asbestos -- cement pipe or sheet can emit airborne fibers if the materials are cut or sawed, or if they are broken.

D. Permissible exposure: Exposure to airborne asbestos fibers may not exceed 0.1 fibers per cubic centimeter of air (0.1 f/cc) averaged over the 8-hour workday, and 1 fiber per cubic centimeter of air (1.0 f/cc) averaged over a 30 minute work period.

II. Health Hazard Data

A. Asbestos can cause disabling respiratory disease and various types of cancers if the fibers are inhaled. Inhaling or ingesting fibers from contaminated clothing or skin can also result in these diseases. The symptoms of these diseases generally do not appear for 20 or more years after initial exposure.

B. Exposure to asbestos has been shown to cause lung cancer, mesothelioma, and cancer of the stomach and colon. Mesothelioma is a rare cancer of the thin membrane lining of the chest and abdomen. Symptoms of mesothelioma include shortness of breath, pain in the walls of the chest, and/or abdominal pain.

III. Respirators and Protective Clothing

A. Respirators: You are required to wear a respirator when performing tasks that result in asbestos exposure that exceeds the permissible exposure limit (PEL) of 0.1 f/cc and when performing certain designated operations. Air-purifying respirators equipped with a high-efficiency particulate air (HEPA) filter can be used where airborne asbestos fiber concentrations do not exceed 1.0 f/cc; otherwise, more protective respirators such as air-supplied, positive-pressure, full facepiece respirators must be used. Disposable respirators or dust masks are not permitted to be used for asbestos work. For effective protection, respirators must fit your face and head snugly. Your employer is required to conduct fit test when you are first assigned a respirator and every 6 months thereafter. Respirators should not be loosened or removed in work situations where their use is required.

B. Protective Clothing: You are required to wear protective clothing in work areas where asbestos fiber concentrations exceed the permissible exposure limit (PEL) of 0.1 f/cc.

IV. Disposal Procedures and Clean-up

A. Wastes that are generated by processes where asbestos is present include:

1. Empty asbestos shipping containers. 2. Process wastes such as cuttings, trimmings, or reject materials. 3. Housekeeping waste from wet-sweeping or HEPA-vacuuming. 4. Asbestos fireproofing or insulating material that is removed from buildings.

5. Asbestos-containing building products removed during building renovation or demolition.

6. Contaminated disposable protective clothing.

B. Empty shipping bags can be flattened under exhaust hoods and packed into airtight containers for disposal. Empty shipping drums are difficult to clean and should be sealed.

C. Vacuum bags or disposable paper filters should not be cleaned, but should be sprayed with a fine water mist and placed into a labeled waste container.

D. Process waste and housekeeping waste should be wetted with water or a mixture of water and surfactant prior to packaging in disposable containers.

E. Asbestos-containing material that if removed from buildings must be disposed of in leak-tight 6-mil plastic bags, plastic-lined cardboard containers, or plastic-lined metal containers. These wastes, which are removed while wet, should be sealed in containers before they dry out to minimize the release of asbestos fibers during handling.

V. Access to Information

A. Each year, your employer is required to inform you of the information contained in this standard and appendices for asbestos. In addition, your employer must instruct you in the proper work practices for handling asbestos-containing materials, and the correct use of protective equipment.

B. Your employer is required to determine whether you are being exposed to asbestos. Your employer must treat exposure to thermal system insulation and sprayed-on and trowled-on surfacing material as asbestos exposure, unless results of laboratory analysis show that the material does not contain asbestos. You or your representative has the right to observe employee measurements and to record the results obtained. Your employer is required to inform you of your exposure, and, if you are exposed above the permissible exposure limit, he or she is required to inform you of the actions that are being taken to reduce your exposure to within the permissible limit.

C. Your employer is required to keep records of your exposures and medical examinations. These exposure records must be kept for at least thirty (30) years. Medical records must be kept for the period of your employment plus thirty (30) years.

D. Your employer is required to release your exposure and medical records to your physician or designated representative upon your written request.

Appendix I to 1915.1001 -- Medical Surveillance Guidelines for Asbestos, Non-Mandatory

I. Route of Entry

Inhalation, ingestion.

II. Toxicology

Clinical evidence of the adverse effects associated with exposure to asbestos is present in the form of several well- conducted epidemiological studies of occupationally exposed workers, family contacts of workers, and persons living near asbestos mines. These studies have shown a definite association between exposure to asbestos and an increased incidence of lung cancer, pleural and peritoneal mesothelioma, gastrointestinal cancer, and asbestosis. The latter is a disabling fibrotic lung disease that is caused only by exposure to asbestos. Exposure to asbestos has also been associated with an increased incidence of esophageal, kidney, laryngeal, pharyngeal, and buccal cavity cancers. As with other known chronic occupational diseases, disease associated with asbestos generally appears about 20 years following the first occurrence of exposure: There are no known acute effects associated with exposure to asbestos.

Epidemiological studies indicate that the risk of lung cancer among exposed workers who smoke cigarettes is greatly increased over the risk of lung cancer among non-exposed smokers or exposed nonsmokers. These studies suggest that cessation of smoking will reduce the risk of lung cancer for a person exposed to asbestos but will not reduce it to the same level of risk as that existing for an exposed worker who has never smoked.

III. Signs and Symptoms of Exposure Related Disease

The signs and symptoms of lung cancer or gastrointestinal cancer induced by exposure to asbestos are not unique, except that a chest X-ray of an exposed patient with lung cancer may show pleural plaques, pleural calcification, or pleural fibrosis. Symptoms characteristic of mesothelioma include shortness of breath, pain in the walls of the chest, or abdominal pain. Mesothelioma has a much longer latency period compared with lung cancer (40 years versus 15- 20 years), and mesothelioma is therefore more likely to be found among workers who were first exposed to asbestos at an early age. Mesothelioma is always fatal.

Asbestosis is pulmonary fibrosis caused by the accumulation of asbestos fibers in the lungs. Symptoms include shortness of breath, coughing, fatigue, and vague feelings of sickness. When the fibrosis worsens, shortness of breath occurs even at rest. The diagnosis of asbestosis is based on a history of exposure to asbestos, the presence of characteristics radiologic changes, end-inspiratory crackles (rales), and other clinical features of fibrosing lung disease. Pleural plaques and thickening are observed on X-rays taken during the early sates of the disease. Asbestosis is often a progressive disease even in the absence of continued exposure, although this appears to be a highly individualized characteristic. In severe cases, death may be caused by respiratory or cardiac failure.

IV. Surveillance and Preventive Considerations

As noted above, exposure to asbestos have been linked to an increased risk of lung cancer, mesothelioma, gastrointestinal cancer, and asbestosis among occupationally exposed workers. Adequate screening tests to determine an employee's potential for developing serious chronic diseases, such as a cancer, from exposure to asbestos do not presently exist. However, some tests, particularly chest X-rays and pulmonary function tests, may indicate that an employee has been overexposed to asbestos increasing his or her risk of developing exposure related chronic diseases. It is important for the physician to become familiar with the operating conditions in which occupational exposure to asbestos is likely to occur. This is particularly important in evaluating medical and work histories and in conducting physical examinations. When an active employee has been identified as having been overexposed to asbestos measures taken by the employer to eliminate or mitigate further exposure should also lower the risk of serious long-term consequences.

The employer is required to institute a medical surveillance program for all employees who are or will be exposed to asbestos at or above the permissible exposure limits (0.1 fiber per cubic centimeter of air) for 30 or more days per year and for all employees who are assigned to wear a negative-pressure respirator. All examinations and procedures must be performed by or under the supervision of licensed physician at a reasonable time and place, and at no cost to the employee.

Although broad latitude is given to the physician in prescribing specific tests to be included in the medical surveillance program, OSHA requires inclusion of the following elements in the routine examination, (i) Medical and work histories with special emphasis directed to symptoms of the respiratory system, cardiovascular system, and digestive tract.

(ii) Completion of the respiratory disease questionnaire contained in Appendix D to this section.

(iii) A physical examination including a chest roentgenogram and pulmonary function test that include measurement of the employee's forced vital capacity (FYC) and forced expiratory volume at one second (FEV(1)).

(iv) Any laboratory or other test that the examining physician deems by sound medical practice to be necessary.

The employer is required to make the prescribed tests available at least annually to those employees covered; more often than specified if recommended by the examining physician; and upon termination of employment.

The employer is required to provide the physician with the following information: A copy of this standard and appendices; a description of the employee's duties as they relate to asbestos exposure; the employee's representative level of exposure to asbestos; a description of any personal protective and respiratory equipment used; and information from previous medical examinations of the affected employee that is not otherwise available to the physician. Making this information available to the physician will aid in the evaluation of the employee's health in relation to assigned duties and fitness to wear personal protective equipment, if required.

The employer is required to obtain a written opinion from the examining physician containing the results of the medical examination; the physician's opinion as to whether the employee has any detected medical conditions that would place the employee at an increased risk of exposure-related disease; any recommended limitations on the employee or on the use of personal protective equipment; and a statement that the employee has been informed by the physician of the results of the medical examination and of any medical conditions related to asbestos exposure that require further explanation or treatment. This written opinion must not reveal specific findings or diagnoses unrelated to exposure to asbestos, and a copy of the opinion must be provided to the affected employee.

Appendix J to 1915.1001 -- Smoking Cessation Program Information for Asbestos -- Non-Mandatory

The following organizations provide smoking cessation information.

1. The National Cancer Institute operates a toll-free Cancer Information Service (CIS) with trained personnel to help you. Call 1-800-4-CANCER* to reach the CIS office serving your area, or write: Office of Cancer Communications, National Cancer Institute, National Institutes of Health, Building 31, Room 10A24, Bethesda, Maryland 20892.

2. American Cancer Society, 3340 Peachtree Road, N.E., Atlanta, Georgia 30026, (404) 320-3333.

The American Cancer Society (ACS) is a voluntary organization composed of 58 divisions and 3,100 local units. Through "The Great American Smokeout" in November, the annual Cancer Crusade in April, and numerous educational materials, ACS helps people learn about the health hazards of smoking and become successful ex-smokers.

3. American Heart Association, 7320 Greenville Avenue, Dallas, Texas 75231, (214) 750-5300.

The American Heart Association (AHA) is a voluntary organization with 130,000 members (physicians, scientists, and laypersons) in 55 state and regional groups. AHA produces a variety of publications and audiovisual materials about the effects of smoking on the heart. AHA also has developed a guidebook for incorporating a weight- control component into smoking cessation programs.

4. American Lung Association, 1740 Broadway, New York, New York 10019, (212) 245-8000.

A voluntary organization of 7,500 members (physicians, nurses, and laypersons), the American Lung Association (ALA) conducted numerous public information programs about the health effects of smoking. ALA has 59 state and 85 local units. The organization actively supports legislation and information campaigns for non- smokers' rights and provides help for smokers who want to quit, for example, through "Freedom From Smoking," a self-help smoking cessation program.

5. Office on Smoking and Health, U.S. Department of Health and Human Services 5600 Fishers Lane, Park Building, Room 110, Rockville, Maryland 20857.

The Office on Smoking and Health (OSHA) is the Department of Health and Human Services' lead agency in smoking control. OSHA has sponsored distribution of publications on smoking-related topics, such as free flyers on relapse after initial quitting, helping a friend or family member quit smoking, the health hazards of smoking, and the effects of parental smoking on teenagers.

* In Hawaii, on Oahu call 524-1234 (call collect from neighboring islands), Spanish-speaking staff members are available during daytime hours to callers from the following areas: California, Florida, Georgia, Illinois, New Jersey (area code 201), New York, and Texas. Consult your local telephone directory for listings of local chapters.

Appendix K to 1915.1001 -- Polarized Light Microscopy of Asbestos -- (Non-Mandatory)

Method number: ID-191 Matrix: Bulk

Collection Procedure

Collect approximately 1 to 2 grams of each type of material and place into separate 20 mL scintillation vials.

Analytical Procedure

A portion of each separate phase is analyzed by gross examination, phase-polar examination, and central stop dispersion microscopy.

Commercial manufacturers and products mentioned in this method are for descriptive use only and do not constitute endorsements by USDOL-OSHA. Similar products from other sources may be substituted.

1. Introduction

This method describes the collection and analysis of asbestos bulk materials by light microscopy techniques including phase- polar illumination and central-stop dispersion microscopy. Some terms unique to asbestos analysis are defined below:

Amphibole: A family of minerals whose crystals are formed by long, thin units which have two thin ribbons of double chain silicate with a brucite ribbon in between. The shape of each unit is similar to an "I beam". Minerals important in asbestos analysis include cummingtonite-grunerite, crocidolite, tremolite-actinolite and anthophyllite.

Asbestos: A term for naturally occurring fibrous minerals. Asbestos includes chrysotile, cummingtonite-grunerite asbestos (amosite), anthophyllite asbestos, tremolite asbestos, crocidolite, actinolite asbestos and any of these minerals which have been chemically treated or altered. The precise chemical formulation of each species varies with the location from which it was mined. Nominal compositions are listed:

Chrysotile....................... Mg(3)Si(2)O(5)(OH)(4)

Crocidolite (Riebeckite asbestos) ............................... Na(2)Fe(3)(2)+Fe(2)(3)+Si(8)O(2)2(OH)(2)

Cummingtonite-Grunerite asbestos (Amosite) ............................... (Mg,Fe)(7)Si(8)O(2)2(OH)(2)

Tremolite-Actinolite asbestos ............................... Ca(2)(Mg,Fe)(5)Si(8)O(2)2(OH)(2)

Anthophyllite asbestos........... (Mg,Fe)(7)Si(8)O(2)2(OH)(2)

Asbestos Fiber: A fiber of asbestos meeting the criteria for a fiber. (See section 3.5.)

Aspect Ratio: The ratio of the length of a fiber to its diameter usually defined as "length : width", e.g. 3:1.

Brucite: A sheet mineral with the composition Mg(OH)(2).

Central Stop Dispersion Staining (microscope): This is a dark field microscope technique that images particles using only light refracted by the particle, excluding light that travels through the particle unrefracted. This is usually accomplished with a McCrone objective or other arrangement which places a circular stop with apparent aperture equal to the objective aperture in the back focal plane of the microscope.

Cleavage Fragments: Mineral particles formed by the comminution of minerals, especially those characterized by relatively parallel sides and moderate aspect ratio.

Differential Counting: The term applied to the practice of excluding certain kinds of fibers from a phase contrast asbestos count because they are not asbestos.

Fiber: A particle longer than or equal to 5 um with a length to width ratio greater than or equal to 3:1. This may include cleavage fragments. (see section 3.5 of this appendix).

Phase Contrast: Contrast obtained in the microscope by causing light scattered by small particles to destructively interfere with unscattered light, thereby enhancing the visibility of very small particles and particles with very low intrinsic contrast.

Phase Contrast Microscope: A microscope configured with a phase mask pair to create phase contrast. The technique which uses this is called Phase Contrast Microscopy (PCM).

Phase-Polar Analysis: This is the use of polarized light in a phase contrast microscope. It is used to see the same size fibers that are visible in air filter analysis. Although fibers finer than 1 um are visible, analysis of these is inferred from analysis of larger bundles that are usually present.

Phase-Polar Microscope: The phase-polar microscope is a phase contrast microscope which has an analyzer, a polarizer, a first order red plate and a rotating phase condenser all in place so that the polarized light image is enhanced by phase contrast.

Sealing Encapsulant: This is a product which can be applied, preferably by spraying, onto an asbestos surface which will seal the surface so that fibers cannot be released.

Serpentine: A mineral family consisting of minerals with the general composition Mg(3)(Si(2)O(5)(OH)(4) having the magnesium in brucite layer over a silicate layer. Minerals important in asbestos analysis included in this family are chrysotile, lizardite, antigorite.

1.1. History

Light microscopy has been used for well over 100 years for the determination of mineral species. This analysis is carried out using specialized polarizing microscopes as well as bright field microscopes. The identification of minerals is an on-going process with many new minerals described each year. The first recorded use of asbestos was in Finland about 2500 B.C. where the material was used in the mud wattle for the wooden huts the people lived in as well as strengthening for pottery. Adverse health aspects of the mineral were noted nearly 2000 years ago when Pliny the Younger wrote about the poor health of slaves in the asbestos mines. Although known to be injurious for centuries, the first modern references to its toxicity were by the British Labor Inspectorate when it banned asbestos dust from the workplace in 1898. Asbestosis cases were described in the literature after the turn of the century. Cancer was first suspected in the mid 1930's and a causal link to mesothelioma was made in 1965. Because of the public concern for worker and public safety with the use of this material, several different types of analysis were applied to the determination of asbestos content. Light microscopy requires a great deal of experience and craft. Attempts were made to apply less subjective methods to the analysis. X-ray diffraction was partially successful in determining the mineral types but was unable to separate out the fibrous portions from the non-fibrous portions. Also, the minimum detection limit for asbestos analysis by X-ray diffraction (XRD) is about 1%. Differential Thermal Analysis (DTA) was no more successful. These provide useful corroborating information when the presence of asbestos has been shown by microscopy; however, neither can determine the difference between fibrous and non-fibrous minerals when both habits are present. The same is true of Infrared Absorption (IR).

When electron microscopy was applied to asbestos analysis, hundreds of fibers were discovered present too small to be visible in any light microscope. There are two different types of electron microscope used for asbestos analysis: Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM). Scanning Electron Microscopy is useful in identifying minerals. The SEM can provide two of the three pieces of information required to identify fibers by electron microscopy: morphology and chemistry. The third is structure as determined by Selected Area Electron Diffraction -- SAED which is performed in the TEM. Although the resolution of the SEM is sufficient for very fine fibers to be seen, accuracy of chemical analysis that can be performed on the fibers varies with fiber diameter in fibers of less than 0.2 um diameter. The TEM is a powerful tool to identify fibers too small to be resolved by light microscopy and should be used in conjunction with this method when necessary. The TEM can provide all three pieces of information required for fiber identification. Most fibers thicker than 1 um can adequately be defined in the light microscope. The light microscope remains as the best instrument for the determination of mineral type. This is because the minerals under investigation were first described analytically with the light microscope. It is inexpensive and gives positive identification for most samples analyzed. Further, when optical techniques are inadequate, there is ample indication that alternative techniques should be used for complete identification of the sample.

1.2. Principle

Minerals consist of atoms that may be arranged in random order or in a regular arrangement. Amorphous materials have atoms in random order while crystalline materials have long range order. Many materials are transparent to light, at least for small particles or for thin sections. The properties of these materials can be investigated by the effect that the material has on light passing through it. The six asbestos minerals are all crystalline with particular properties that have been identified and cataloged. These six minerals are anisotropic. They have a regular array of atoms, but the arrangement is not the same in all directions. Each major direction of the crystal presents a different regularity. Light photons travelling in each of these main directions will encounter different electrical neighborhoods, affecting the path and time of travel. The techniques outlined in this method use the fact that light traveling through fibers or crystals in different directions will behave differently, but predictably. The behavior of the light as it travels through a crystal can be measured and compared with known or determined values to identify the mineral species. Usually, Polarized Light Microscopy (PLM) is performed with strain-free objectives on a bright-field microscope platform. This would limit the resolution of the microscope to about 0.4 um. Because OSHA requires the counting and identification of fibers visible in phase contrast, the phase contrast platform is used to visualize the fibers with the polarizing elements added into the light path. Polarized light methods cannot identify fibers finer than about 1 um in diameter even though they are visible. The finest fibers are usually identified by inference from the presence of larger, identifiable fiber bundles. When fibers are present, but not identifiable by light microscopy, use either SEM or TEM to determine the fiber identity.

1.3. Advantages and Disadvantages

The advantages of light microcopy are:

(a) Basic identification of the materials was first performed by light microscopy and gross analysis. This provides a large base of published information against which to check analysis and analytical technique.

(b) The analysis is specific to fibers. The minerals present can exist in asbestiform, fibrous, prismatic, or massive varieties all at the same time. Therefore, bulk methods of analysis such as X-ray diffraction, IR analysis, DTA, etc. are inappropriate where the material is not known to be fibrous.

(c) The analysis is quick, requires little preparation time, and can be performed on-site if a suitably equipped microscope is available.

The disadvantages are:

(a) Even using phase-polar illumination, not all the fibers present may be seen. This is a problem for very low asbestos concentrations where agglomerations or large bundles of fibers may not be present to allow identification by inference.

(b) The method requires a great degree of sophistication on the part of the microscopist. An analyst is only as useful as his mental catalog of images. Therefore, a microscopist's accuracy is enhanced by experience. The mineralogical training of the analyst is very important. It is the basis on which subjective decisions are made.

(c) The method uses only a tiny amount of material for analysis. This may lead to sampling bias and false results (high or low). This is especially true if the sample is severely inhomogeneous.

(d) Fibers may be bound in a matrix and not distinguishable as fibers so identification cannot be made.

1.4. Method Performance

1.4.1. This method can be used for determination of asbestos content from 0 to 100% asbestos. The detection limit has not been adequately determined, although for selected samples, the limit is very low, depending on the number of particles examined. For mostly homogeneous, finely divided samples, with no difficult fibrous interferences, the detection limit is below 1%. For inhomogeneous samples (most samples), the detection limit remains undefined. NIST has conducted proficiency testing of laboratories on a national scale. Although each round is reported statistically with an average, control limits, etc., the results indicate a difficulty in establishing precision especially in the low concentration range. It is suspected that there is significant bias in the low range especially near 1%. EPA tried to remedy this by requiring a mandatory point counting scheme for samples less than 10%. The point counting procedure is tedious, and may introduce significant biases of its own. It has not been incorporated into this method.

1.4.2. The precision and accuracy of the quantitation tests performed in this method are unknown. Concentrations are easier to determine in commercial products where asbestos was deliberately added because the amount is usually more than a few percent. An analyst's results can be "calibrated" against the known amounts added by the manufacturer. For geological samples, the degree of homogeneity affects the precision.

1.4.3. The performance of the method is analyst dependent. The analyst must choose carefully and not necessarily randomly the portions for analysis to assure that detection of asbestos occurs when it is present. For this reason, the analyst must have adequate training in sample preparation, and experience in the location and identification of asbestos in samples. This is usually accomplished through substantial on-the-job training as well as formal education in mineralogy and microscopy.

1.5. Interferences

Any material which is long, thin, and small enough to be viewed under the microscope can be considered an interference for asbestos. There are literally hundreds of interferences in workplaces. The techniques described in this method are normally sufficient to eliminate the interferences. An analyst's success in eliminating the interferences depends on proper training.

Asbestos minerals belong to two mineral families: the serpentines and the amphiboles. In the serpentine family, the only common fibrous mineral is chrysotile. Occasionally, the mineral antigorite occurs in a fibril habit with morphology similar to the amphiboles. The amphibole minerals consist of a score of different minerals of which only five are regulated by federal standard: amosite, crocidolite, anthophyllite asbestos, tremolite asbestos and actinolite asbestos. These are the only amphibole minerals that have been commercially exploited for their fibrous properties; however, the rest can and do occur occasionally in asbestiform habit.

In addition to the related mineral interferences, other minerals common in building material may present a problem for some microscopists: gypsum, anhydrite, brucite, quartz fibers, talc fibers or ribbons, wollastonite, perlite, attapulgite, etc. Other fibrous materials commonly present in workplaces are: fiberglass, mineral wool, ceramic wool, refractory ceramic fibers, kevlar, nomex, synthetic fibers, graphite or carbon fibers, cellulose (paper or wood) fibers, metal fibers, etc.

Matrix embedding material can sometimes be a negative interference. The analyst may not be able to easily extract the fibers from the matrix in order to use the method. Where possible, remove the matrix before the analysis, taking careful note of the loss of weight. Some common matrix materials are: vinyl, rubber, tar, paint, plant fiber, cement, and epoxy. A further negative interference is that the asbestos fibers themselves may be either too small to be seen in Phase contrast Microscopy (PCM) or of a very low fibrous quality, having the appearance of plant fibers. The analyst's ability to deal with these materials increases with experience.

1.6. Uses and Occupational Exposure

Asbestos is ubiquitous in the environment. More than 40% of the land area of the United States is composed of minerals which may contain asbestos. Fortunately, the actual formation of great amounts of asbestos is relatively rare. Nonetheless, there are locations in which environmental exposure can be severe such as in the Serpentine Hills of California.

There are thousands of uses for asbestos in industry and the home. Asbestos abatement workers are the most current segment of the population to have occupational exposure to great amounts of asbestos. If the material is undisturbed, there is no exposure. Exposure occurs when the asbestos-containing material is abraded or otherwise disturbed during maintenance operations or some other activity. Approximately 95% of the asbestos in place in the United States is chrysotile.

Amosite and crocidolite make up nearly all the difference. Tremolite and anthophyllite make up a very small percentage. Tremolite is found in extremely small amounts in certain chrysotile deposits. Actinolite exposure is probably greatest from environmental sources, but has been identified in vermiculite containing, sprayed-on insulating materials which may have been certified as asbestos-free.

1.7. Physical and Chemical Properties

The nominal chemical compositions for the asbestos minerals were given in Section 1. Compared to cleavage fragments of the same minerals, asbestiform fibers possess a high tensile strength along the fiber axis. They are chemically inert, non-combustible, and heat resistant. Except for chrysotile, they are insoluble in Hydrochloric acid (HCl). Chrysotile is slightly soluble in HCl. Asbestos has high electrical resistance and good sound absorbing characteristics. It can be woven into cables, fabrics or other textiles, or matted into papers, felts, and mats.

1.8. Toxicology (This Section is for Information Only and Should Not Be Taken as OSHA Policy)

Possible physiologic results of respiratory exposure to asbestos are mesothelioma of the pleura or peritoneum, interstitial fibrosis, asbestosis, pneumoconiosis, or respiratory cancer. The possible consequences of asbestos exposure are detailed in the NIOSH Criteria Document or in the OSHA Asbestos Standards 29 CFR 1910.1001 and 29 CFR 1926.1101.

2. Sampling Procedure

2.1. Equipment for Sampling

(a) Tube or cork borer sampling device (b) Knife (c) 20 mL scintillation vial or similar vial (d) Sealing encapsulant

2.2. Safety Precautions

Asbestos is a known carcinogen. Take care when sampling. While in an asbestos-containing atmosphere, a properly selected and fit- tested respirator should be worn. Take samples in a manner to cause the least amount of dust. Follow these general guidelines:

(a) Do not make unnecessary dust. (b) Take only a small amount (1 to 2 g). (c) Tightly close the sample container. (d) Use encapsulant to seal the spot where the sample was taken, if necessary.

2.3. Sampling procedure

Samples of any suspect material should be taken from an inconspicuous place. Where the material is to remain, seal the sampling wound with an encapsulant to eliminate the potential for exposure from the sample site. Microscopy requires only a few milligrams of material. The amount that will fill a 20 mL scintillation vial is more than adequate. Be sure to collect samples from all layers and phases of material. If possible, make separate samples of each different phase of the material. This will aid in determining the actual hazard. DO NOT USE ENVELOPES, PLASTIC OR PAPER BAGS OF ANY KIND TO COLLECT SAMPLES. The use of plastic bags presents a contamination hazard to laboratory personnel and to other samples. When these containers are opened, a bellows effect blows fibers out of the container onto everything, including the person opening the container.

If a cork-borer type sampler is available, push the tube through the material all the way, so that all layers of material are sampled. Some samplers are intended to be disposable. These should be capped and sent to the laboratory. If a non-disposable cork borer is used, empty the contents into a scintillation vial and send to the laboratory. Vigorously and completely clean the cork borer between samples.

2.4 Shipment

Samples packed in glass vials must not touch or they might break in shipment.

(a) Seal the samples with a sample seal (such as the OSHA 21) over the end to guard against tampering and to identify the sample.

(b) Package the bulk samples in separate packages from the air samples. They may cross-contaminate each other and will invalidate the results of the air samples.

(c) Include identifying paperwork with the samples, but not in contact with the suspected asbestos.

(d) To maintain sample accountability, ship the samples by certified mail, overnight express, or hand carry them to the laboratory.

3. Analysis

The analysis of asbestos samples can be divided into two major parts:

sample preparation and microscopy. Because of the different asbestos uses that may be encountered by the analyst, each sample may need different preparation steps. The choices are outlined below. There are several different tests that are performed to identify the asbestos species and determine the percentage. They will be explained below.

3.1. Safety

(a) Do not create unnecessary dust. Handle the samples in HEPA- filter equipped hoods. If samples are received in bags, envelopes or other inappropriate container, open them only in a hood having a face velocity at or greater than 100 fpm. Transfer a small amount to a scintillation vial and only handle the smaller amount.

(b) Open samples in a hood, never in the open lab area.

(c) Index of refraction oils can be toxic. Take care not to get this material on the skin. Wash immediately with soap and water if this happens.

(d) Samples that have been heated in the muffle furnace or the drying oven may be hot. Handle them with tongs until they are cool enough to handle.

(e) Some of the solvents used, such as THF (tetrahydrofuran), are toxic and should only be handled in an appropriate fume hood and according to instructions given in the Material Safety Data Sheet (MSDS).

3.2. Equipment

(a) Phase contrast microscope with 10x, 16x and 40x objectives, 10x wide-field eyepieces, G-22 Walton-Beckett graticule, Whipple disk, polarizer, analyzer and first order red or gypsum plate, 100 Watt illuminator, rotating position condenser with oversize phase rings, central stop dispersion objective, Kohler illumination and a rotating mechanicalstage. (See Figure 1).

(b) Stereo microscope with reflected light illumination, transmitted light illumination, polarizer, analyzer and first order red or gypsum plate, and rotating stage.

(c) Negative pressure hood for the stereo microscope

(d) Muffle furnace capable of 600 deg.C

(e) Drying oven capable of 50-150 deg.C

(f) Aluminum specimen pans

(g) Tongs for handling samples in the furnace

(h) High dispersion index of refraction oils (Special for dispersion staining.)

n = 1.550 n = 1.585 n = 1.590 n = 1.605 n = 1.620 n = 1.670 n = 1.680 n = 1.690

(i) A set of index of refraction oils from about n=1.350 to n=2.000 in n=0.005 increments. (Standard for Becke line analysis.)

(j) Glass slides with painted or frosted ends 1 x 3 inches 1mm thick, precleaned.

(k) Cover Slips 22 x 22 mm, #1 1/2

(l) Paper clips or dissection needles

(m) Hand grinder

(n) Scalpel with both #10 and #11 blades

(o) 0.1 molar HCl

(p) Decalcifying solution (Baxter Scientific Products Ethylenediaminetetraacetic Acid,

Tetrasodium.............................. 0.7 g/l Sodium Potassium

Tartrate................ 8.0 mg/liter Hydrochloric

Acid........................ 99.2 g/liter Sodium

Tartrate.......................... 0.14 g/liter

(q) Tetrahydrofuran (THF)

(r) Hotplate capable of 60 deg.C

(s) Balance

(t) Hacksaw blade

(u) Ruby mortar and pestle

3.3. Sample Pre-Preparation

Sample preparation begins with pre-preparation which may include chemical reduction of the matrix, heating the sample to dryness or heating in the muffle furnace. The end result is a sample which has been reduced to a powder that is sufficiently fine to fit under the cover slip. Analyze different phases of samples separately, e.g., tile and the tile mastic should be analyzed separately as the mastic may contain asbestos while the tile may not.

(a) Wet Samples

Samples with a high water content will not give the proper dispersion colors and must be dried prior to sample mounting. Remove the lid of the scintillation vial, place the bottle in the drying oven and heat at 100 deg.C to dryness (usually about 2 h). Samples which are not submitted to the lab in glass must be removed and placed in glass vials or aluminum weighing pans before placing them in the drying oven.

(b) Samples With Organic Interference -- Muffle Furnace

These may include samples with tar as a matrix, vinyl asbestos tile, or any other organic that can be reduced by heating. Remove the sample from the vial and weigh in a balance to determine the weight of the submitted portion. Place the sample in a muffle furnace at 500 deg.C for 1 to 2 h or until all obvious organic material has been removed. Retrieve, cool and weigh again to determine the weight loss on ignition. This is necessary to determine the asbestos content of the submitted sample, because the analyst will be looking at a reduced sample.

Notes: Heating above 600 deg.C will cause the sample to undergo a structural change which, given sufficient time, will convert the chrysotile to forsterite. Heating even at lower temperatures for 1 to 2 h may have a measurable effect on the optical properties of the minerals. If the analyst is unsure of what to expect, a sample of standard asbestos should be heated to the same temperature for the same length of time so that it can be examined for the proper interpretation.

(c) Samples With Organic Interference -- THF

Vinyl asbestos tile is the most common material treated with this solvent, although, substances containing tar will sometimes yield to this treatment. Select a portion of the material and then grind it up if possible. Weigh the sample and place it in a test tube. Add sufficient THF to dissolve the organic matrix. This is usually about 4 to 5 mL. Remember, THF is highly flammable. Filter the remaining material through a tared silver membrane, dry and weigh to determine how much is left after the solvent extraction. Further process the sample to remove carbonate or mount directly.

(d) Samples With Carbonate Interference

Carbonate material is often found on fibers and sometimes must be removed in order to perform dispersion microscopy. Weigh out a portion of the material and place it in a test tube. Add a sufficient amount of 0.1 M HCl or decalcifying solution in the tube to react all the carbonate as evidenced by gas formation; i.e., when the gas bubbles stop, add a little more solution. If no more gas forms, the reaction is complete. Filter the material out through a tared silver membrane, dry and weigh to determine the weight lost.

3.4. Sample Preparation

Samples must be prepared so that accurate determination can be made of the asbestos type and amount present. The following steps are carried out in the low-flow hood (a low-flow hood has less than 50 fpm flow):

(1) If the sample has large lumps, is hard, or cannot be made to lie under a cover slip, the grain size must be reduced. Place a small amount between two slides and grind the material between them or grind a small amount in a clean mortar and pestle. The choice of whether to use an alumina, ruby, or diamond mortar depends on the hardness of the material. Impact damage can alter the asbestos mineral if too much mechanical shock occurs. (Freezer mills can completely destroy the observable crystallinity of asbestos and should not be used). For some samples, a portion of material can be shaved off with a scalpel, ground off with a hand grinder or hack saw blade.

The preparation tools should either be disposable or cleaned thoroughly. Use vigorous scrubbing to loosen the fibers during the washing. Rinse the implements with copious amounts of water and air- dry in a dust-free environment.

(2) If the sample is powder or has been reduced as in 1) above, it is ready to mount. Place a glass slide on a piece of optical tissue and write the identification on the painted or frosted end. Place two drops of index of refraction medium n=1.550 on the slide. (The medium n=1.550 is chosen because it is the matching index for chrysotile. Dip the end of a clean paper-clip or dissecting needle into the droplet of refraction medium on the slide to moisten it. Then dip the probe into the powder sample. Transfer what sticks on the probe to the slide. The material on the end of the probe should have a diameter of about 3 mm for a good mount. If the material is very fine, less sample may be appropriate. For non-powder samples such as fiber mats, forceps should be used to transfer a small amount of material to the slide. Stir the material in the medium on the slide, spreading it out and making the preparation as uniform as possible. Place a cover-slip on the preparation by gently lowering onto the slide and allowing it to fall "trapdoor" fashion on the preparation to push out any bubbles. Press gently on the cover slip to even out the distribution of particulate on the slide. If there is insufficient mounting oil on the slide, one or two drops may be placed near the edge of the coverslip on the slide. Capillary action will draw the necessary amount of liquid into the preparation. Remove excess oil with the point of a laboratory wiper.

Treat at least two different areas of each phase in this fashion. Choose representative areas of the sample. It may be useful to select particular areas or fibers for analysis. This is useful to identify asbestos in severely inhomogeneous samples.

When it is determined that amphiboles may be present, repeat the above process using the appropriate high- dispersion oils until an identification is made or all six asbestos minerals have been ruled out. Note that percent determination must be done in the index medium 1.550 because amphiboles tend to disappear in their matching mediums.

3.5. Analytical procedure

Note: This method presumes some knowledge of mineralogy and optical petrography.

The analysis consists of three parts: The determination of whether there is asbestos present, what type is present and the determination of how much is present. The general flow of the analysis is:

(1) Gross examination.

(2) Examination under polarized light on the stereo microscope.

(3) Examination by phase-polar illumination on the compound phase microscope.

(4) Determination of species by dispersion stain. Examination by Becke line analysis may also be used; however, this is usually more cumbersome for asbestos determination.

(5) Difficult samples may need to be analyzed by SEM or TEM, or the results from those techniques combined with light microscopy for a definitive identification. Identification of a particle as asbestos requires that it be asbestiform. Description of particles should follow the suggestion of Campbell. (Figure 1)

(For Figure 1, Particle difinitions showing mineral
growth habits, see paper copy)

For the purpose of regulation, the mineral must be one of the six minerals covered and must be in the asbestos growth habit. Large specimen samples of asbestos generally have the gross appearance of wood. Fibers are easily parted from it. Asbestos fibers are very long compared with their widths. The fibers have a very high tensile strength as demonstrated by bending without breaking. Asbestos fibers exist in bundles that are easily parted, show longitudinal fine structure and may be tufted at the ends showing "bundle of sticks" morphology. In the microscope some of these properties may not be observable. Amphiboles do not always show striations along their length even when they are asbestos. Neither will they always show tufting. They generally do not show a curved nature except for very long fibers. Asbestos and asbestiform minerals are usually characterized in groups by extremely high aspect ratios (greater than 100:1). While aspect ratio analysis is useful for characterizing populations of fibers, it cannot be used to identify individual fibers of intermediate to short aspect ratio. Observation of many fibers is often necessary to determine whether a sample consists of "cleavage fragments" or of asbestos fibers.

Most cleavage fragments of the asbestos minerals are easily distinguishable from true asbestos fibers. This is because true cleavage fragments usually have larger diameters than 1 um. Internal structure of particles larger than this usually shows them to have no internal fibrillar structure. In addition, cleavage fragments of the monoclinic amphiboles show inclined extinction under crossed polars with no compensator. Asbestos fibers usually show extinction at zero degrees or ambiguous extinction if any at all. Morphologically, the larger cleavage fragments are obvious by their blunt or stepped ends showing prismatic habit. Also, they tend to be acicular rather than filiform.

Where the particles are less than 1 um in diameter and have an aspect ratio greater than or equal to 3:1, it is recommended that the sample be analyzed by SEM or TEM if there is any question whether the fibers are cleavage fragments or asbestiform particles.

Care must be taken when analyzing by electron microscopy because the interferences are different from those in light microscopy and may structurally be very similar to asbestos. The classic interference is between anthophyllite and biopyribole or intermediate fiber. Use the same morphological clues for electron microscopy as are used for light microscopy, e.g. fibril splitting, internal longitudinal striation, fraying, curvature, etc.

(1) Gross examination:

Examine the sample, preferably in the glass vial. Determine the presence of any obvious fibrous component. Estimate a percentage based on previous experience and current observation. Determine whether any pre-preparation is necessary. Determine the number of phases present. This step may be carried out or augmented by observation at 6 to 40 x under a stereo microscope.

(2) After performing any necessary pre-preparation, prepare slides of each phase as described above. Two preparations of the same phase in the same index medium can be made side-by-side on the same glass for convenience. Examine with the polarizing stereo microscope. Estimate the percentage of asbestos based on the amount of birefringent fiber present.

(3) Examine the slides on the phase-polar microscopes at magnifications of 160 and 400 x . Note the morphology of the fibers. Long, thin, very straight fibers with little curvature are indicative of fibers from the amphibole family. Curved, wavy fibers are usually indicative of chrysotile. Estimate the percentage of asbestos on the phase-polar microscope under conditions of crossed polars and a gypsum plate. Fibers smaller than 1.0 um in thickness must be identified by inference to the presence of larger, identifiable fibers and morphology. If no larger fibers are visible, electron microscopy should be performed. At this point, only a tentative identification can be made. Full identification must be made with dispersion microscopy. Details of the tests are included in the appendices.

(4) Once fibers have been determined to be present, they must be identified. Adjust the microscope for dispersion mode and observe the fibers. The microscope has a rotating stage, one polarizing element, and a system for generating dark-field dispersion microscopy (see Section 4.6. of this appendix). Align a fiber with its length parallel to the polarizer and note the color of the Becke lines. Rotate the stage to bring the fiber length perpendicular to the polarizer and note the color. Repeat this process for every fiber or fiber bundle examined. The colors must be consistent with the colors generated by standard asbestos reference materials for a positive identification. In n=1.550, amphiboles will generally show a yellow to straw-yellow color indicating that the fiber indices of refraction are higher than the liquid. If long, thin fibers are noted and the colors are yellow, prepare further slides as above in the suggested matching liquids listed below:

Type of asbestos Index of refraction
Chrysotile n = 1.550
Amosite n = 1.670 r 1.680
Crocidolite n = 1.690
Anthophyllite n = 1.605 nd 1.620
Tremolite n = 1.605 and 1.620
Actinolite n = 1.620

Where more than one liquid is suggested, the first is preferred;

however, in some cases this liquid will not give good dispersion color. Take care to avoid interferences in the other liquid; e.g., wollastonite in n=1.620 will give the same colors as tremolite. In n=1.605 wollastonite will appear yellow in all directions. Wollastonite may be determined under crossed polars as it will change from blue to yellow as it is rotated along its fiber axis by tapping on the cover slip. Asbestos minerals will not change in this way.

Determination of the angle of extinction may, when present, aid in the determination of anthophyllite from tremolite. True asbestos fibers usually have 0 deg. extinction or ambiguous extinction, while cleavage fragments have more definite extinction.

Continue analysis until both preparations have been examined and all present species of asbestos are identified. If there are no fibers present, or there is less than 0.1% present, end the analysis with the minimum number of slides (2).

(5) Some fibers have a coating on them which makes dispersion microscopy very difficult or impossible. Becke line analysis or electron microscopy may be performed in those cases. Determine the percentage by light microscopy. TEM analysis tends to overestimate the actual percentage present.

(6) Percentage determination is an estimate of occluded area, tempered by gross observation. Gross observation information is used to make sure that the high magnification microscopy does not greatly over- or under-estimate the amount of fiber present. This part of the analysis requires a great deal of experience. Satisfactory models for asbestos content analysis have not yet been developed, although some models based on metallurgical grain-size determination have found some utility. Estimation is more easily handled in situations where the grain sizes visible at about 160 x are about the same and the sample is relatively homogeneous.

View all of the area under the cover slip to make the percentage determination. View the fields while moving the stage, paying attention to the clumps of material. These are not usually the best areas to perform dispersion microscopy because of the interference from other materials. But, they are the areas most likely to represent the accurate percentage in the sample. Small amounts of asbestos require slower scanning and more frequent analysis of individual fields.

Report the area occluded by asbestos as the concentration. This estimate does not generally take into consideration the difference in density of the different species present in the sample. For most samples this is adequate. Simulation studies with similar materials must be carried out to apply microvisual estimation for that purpose and is beyond the scope of this procedure.

(7) Where successive concentrations have been made by chemical or physical means, the amount reported is the percentage of the material in the "as submitted" or original state. The percentage determined by microscopy is multiplied by the fractions remaining after pre-preparation steps to give the percentage in the original sample. For example:

Step 1. 60% remains after heating at 550 deg.C for 1 h.

Step 2. 30% of the residue of step 1 remains after dissolution of carbonate in 0.1 m HCl.

Step 3. Microvisual estimation determines that 5% of the sample is chrysotile asbestos.

 

  • The reported result is:

 

R = (Microvisual result in percent) x (Fraction remaining after step 2) x (Fraction remaining of original sample after step 1)
R = (5) x (.30) x (.60) = 0.9%

(8) Report the percent and type of asbestos present. For samples where asbestos was identified, but is less than 1.0%, report "Asbestos present, less than 1.0%." There must have been at least two observed fibers or fiber bundles in the two preparations to be reported as present. For samples where asbestos was not seen, report as "None Detected."

Auxiliary Information

Because of the subjective nature of asbestos analysis, certain concepts and procedures need to be discussed in more depth. This information will help the analyst understand why some of the procedures are carried out the way they are.

4.1. Light

Light is electromagnetic energy. It travels from its source in packets called quanta. It is instructive to consider light as a plane wave. The light has a direction of travel. Perpendicular to this and mutually perpendicular to each other, are two vector components. One is the magnetic vector and the other is the electric vector. We shall only be concerned with the electric vector. In this description, the interaction of the vector and the mineral will describe all the observable phenomena. From a light source such a microscope illuminator, light travels in all different direction from the filament.

In any given direction away from the filament, the electric vector is perpendicular to the direction of travel of a light ray. While perpendicular, its orientation is random about the travel axis. If the electric vectors from all the light rays were lined up by passing the light through a filter that would only let light rays with electric vectors oriented in one direction pass, the light would then be POLARIZED.

Polarized light interacts with matter in the direction of the electric vector. This is the polarization direction. Using this property it is possible to use polarized light to probe different materials and identify them by how they interact with light. The speed of light in a vacuum is a constant at about 2.99 x 10(8) m/s. When light travels in different materials such as air, water, minerals or oil, it does not travel at this speed. It travels slower. This slowing is a function of both the material through which the light is traveling and the wavelength or frequency of the light. In general, the more dense the material, the slower the light travels. Also, generally, the higher the frequency, the slower the light will travel. The ratio of the speed of light in a vacuum to that in a material is called the index of refraction (n). It is usually measured at 589 nm (the sodium D line). If white light (light containing all the visible wavelengths) travels through a material, rays of longer wavelengths will travel faster than those of shorter wavelengths, this separation is called dispersion. Dispersion is used as an identifier of materials as described in Section 4.6.

4.2. Material Properties

Materials are either amorphous or crystalline. The difference between these two descriptions depends on the positions of the atoms in them. The atoms in amorphous materials are randomly arranged with no long range order. An example of an amorphous material is glass. The atoms in crystalline materials, on the other hand, are in regular arrays and have long range order. Most of the atoms can be found in highly predictable locations. Examples of crystalline material are salt, gold, and the asbestos minerals.

It is beyond the scope of this method to describe the different types of crystalline materials that can be found, or the full description of the classes into which they can fall. However, some general crystallography is provided below to give a foundation to the procedures described.

With the exception of anthophyllite, all the asbestos minerals belong to the monoclinic crystal type. The unit cell is the basic repeating unit of the crystal and for monoclinic crystals can be described as having three unequal sides, two 90 deg. angles and one angle not equal to 90 deg.. The orthorhombic group, of which anthophyllite is a member has three unequal sides and three 90 deg. angles. The unequal sides are a consequence of the complexity of fitting the different atoms into the unit cell. Although the atoms are in a regular array, that array is not symmetrical in all directions. There is long range order in the three major directions of the crystal. However, the order is different in each of the three directions. This has the effect that the index of refraction is different in each of the three directions. Using polarized light, we can investigate the index of refraction in each of the directions and identify the mineral or material under investigation. The indices alpha, beta, and gamma are used to identify the lowest, middle, and highest index of refraction respectively. The x direction, associated with alpha is called the fast axis. Conversely, the z direction is associated with gamma and is the slow direction. Crocidolite has alpha along the fiber length making it "length-fast". The remainder of the asbestos minerals have the gamma axis along the fiber length. They are called "length-slow". This orientation to fiber length is used to aid in the identification of asbestos.

4.3. Polarized Light Technique

Polarized light microscopy as described in this section uses the phase-polar microscope described in Section 3.2. A phase contrast microscope is fitted with two polarizing elements, one below and one above the sample. The polarizers have their polarization directions at right angles to each other. Depending on the tests performed, there may be a compensator between these two polarizing elements. A compensator is a piece of mineral with known properties that "compensates" for some deficiency in the optical train. Light emerging from a polarizing element has its electric vector pointing in the polarization direction of the element. The light will not be subsequently transmitted through a second element set at a right angle to the first element. Unless the light is altered as it passes from one element to the other, there is no transmission of light.

4.4. Angle of Extinction

Crystals which have different crystal regularity in two or three main directions are said to be anisotropic. They have a different index of refraction in each of the main directions. When such a crystal is inserted between the crossed polars, the field of view is no longer dark but shows the crystal in color. The color depends on the properties of the crystal. The light acts as if it travels through the crystal along the optical axes. If a crystal optical axis were lined up along one of the polarizing directions (either the polarizer or the analyzer) the light would appear to travel only in that direction, and it would blink out or go dark. The difference in degrees between the fiber direction and the angle at which it blinks out is called the angle of extinction. When this angle can be measured, it is useful in identifying the mineral. The procedure for measuring the angle of extinction is to first identify the polarization direction in the microscope. A commercial alignment slide can be used to establish the polarization directions or use anthophyllite or another suitable mineral. This mineral has a zero degree angle of extinction and will go dark to extinction as it aligns with the polarization directions. When a fiber of anthophyllite has gone to extinction, align the eyepiece reticle or graticule with the fiber so that there is a visual cue as to the direction of polarization in the field of view. Tape or otherwise secure the eyepiece in this position so it will not shift.

After the polarization direction has been identified in the field of view, move the particle of interest to the center of the field of view and align it with the polarization direction. For fibers, align the fiber along this direction. Note the angular reading of the rotating stage. Looking at the particle, rotate the stage until the fiber goes dark or "blinks out". Again note the reading of the stage. The difference in the first reading and the second is an angle of extinction.

The angle measured may vary as the orientation of the fiber changes about its long axis. Tables of mineralogical data usually report the maximum angle of extinction. Asbestos forming minerals, when they exhibit an angle of extinction, usually do show an angle of extinction close to the reported maximum, or as appropriate depending on the substitution chemistry.

4.5. Crossed Polars With Compensator

When the optical axes of a crystal are not lined up along one of the polarizing directions (either the polarizer or the analyzer) part of the light travels along one axis and part travels along the other visible axis. This is characteristic of birefringent materials.

The color depends on the difference of the two visible indices of refraction and the thickness of the crystal. The maximum difference available is the difference between the alpha and the gamma axes. This maximum difference is usually tabulated as the birefringence of the crystal.

For this test, align the fiber at 45 deg. to the polarization directions in order to maximize the contribution to each of the optical axes. The colors seen are called retardation colors. They arise from the recombination of light which has traveled through the two separate directions of the crystal. One of the rays is retarded behind the other since the light in that direction travels slower. On recombination, some of the colors which make up white light are enhanced by constructive interference and some are suppressed by destructive interference. The result is a color dependent on the difference between the indices and the thickness of the crystal. The proper colors, thicknesses, and retardations are shown on a Michel-Levy chart. The three items, retardation, thickness and birefringence are related by the following relationship:

R = t(n gamma -- n alpha) R = retardation, t = crystal thickness in um, and n alpha, gamma = indices of refraction.

Examination of the equation for asbestos minerals reveals that the visible colors for almost all common asbestos minerals and fiber sizes are shades of gray and black. The eye is relatively poor at discriminating different shades of gray. It is very good at discriminating different colors. In order to compensate for the low retardation, a compensator is added to the light train between the polarization elements. The compensator used for this test is a gypsum plate of known thickness and birefringence. Such a compensator when oriented at 45 deg. to the polarizer direction, provides a retardation of 530 nm of the 530 nm wavelength color. This enhances the red color and gives the background a characteristic red to red-magenta color. If this "full-wave" compensator is in place when the asbestos preparation is inserted into the light train, the colors seen on the fibers are quite different. Gypsum, like asbestos has a fast axis and a slow axis. When a fiber is aligned with its fast axis in the same direction as the fast axis of the gypsum plate, the ray vibrating in the slow direction is retarded by both the asbestos and the gypsum. This results in a higher retardation than would be present for either of the two minerals. The color seen is a second order blue. When the fiber is rotated 90 deg. using the rotating stage, the slow direction of the fiber is now aligned with the fast direction of the gypsum and the fast direction of the fiber is aligned with the slow direction of the gypsum. Thus, one ray vibrates faster in the fast direction of the gypsum, and slower in the slow direction of the fiber; the other ray will vibrate slower in the slow direction of the gypsum and faster in the fast direction of the fiber. In this case, the effect is subtractive and the color seen is a first order yellow. As long as the fiber thickness does not add appreciably to the color, the same basic colors will be seen for all asbestos types except crocidolite. In crocidolite the colors will be weaker, may be in the opposite directions, and will be altered by the blue absorption color natural to crocidolite. Hundreds of other materials will give the same colors as asbestos, and therefore, this test is not definitive for asbestos. The test is useful in discriminating against fiberglass or other amorphous fibers such as some synthetic fibers. Certain synthetic fibers will show retardation colors different than asbestos; however, there are some forms of polyethylene and aramid which will show morphology and retardation colors similar to asbestos minerals. This test must be supplemented with a positive identification test when birefringent fibers are present which can not be excluded by morphology. This test is relatively ineffective for use on fibers less than 1 um in diameter. For positive confirmation TEM or SEM should be used if no larger bundles or fibers are visible.

4.6. Dispersion Staining

Dispersion microscopy or dispersion staining is the method of choice for the identification of asbestos in bulk materials. Becke line analysis is used by some laboratories and yields the same results as does dispersion staining for asbestos and can be used in lieu of dispersion staining. Dispersion staining is performed on the same platform as the phase-polar analysis with the analyzer and compensator removed. One polarizing element remains to define the direction of the light so that the different indices of refraction of the fibers may be separately determined. Dispersion microscopy is a dark-field technique when used for asbestos. Particles are imaged with scattered light. Light which is unscattered is blocked from reaching the eye either by the back field image mask in a McCrone objective or a back field image mask in the phase condenser. The most convenient method is to use the rotating phase condenser to move an oversized phase ring into place. The ideal size for this ring is for the central disk to be just larger than the objective entry aperture as viewed in the back focal plane. The larger the disk, the less scattered light reaches the eye. This will have the effect of diminishing the intensity of dispersion color and will shift the actual color seen. The colors seen vary even on microscopes from the same manufacturer. This is due to the different bands of wavelength exclusion by different mask sizes. The mask may either reside in the condenser or in the objective back focal plane. It is imperative that the analyst determine by experimentation with asbestos standards what the appropriate colors should be for each asbestos type. The colors depend also on the temperature of the preparation and the exact chemistry of the asbestos. Therefore, some slight differences from the standards should be allowed. This is not a serious problem for commercial asbestos uses. This technique is used for identification of the indices of refraction for fibers by recognition of color. There is no direct numerical readout of the index of refraction. Correlation of color to actual index of refraction is possible by referral to published conversion tables. This is not necessary for the analysis of asbestos. Recognition of appropriate colors along with the proper morphology are deemed sufficient to identify the commercial asbestos minerals. Other techniques including SEM, TEM, and XRD may be required to provide additional information in order to identify other types of asbestos.

Make a preparation in the suspected matching high dispersion oil, e.g., n = 1.550 for chrysotile. Perform the preliminary tests to determine whether the fibers are birefringent or not. Take note of the morphological character. Wavy fibers are indicative of chrysotile while long, straight, thin, frayed fibers are indicative of amphibole asbestos. This can aid in the selection of the appropriate matching oil. The microscope is set up and the polarization direction is noted as in Section 4.4. Align a fiber with the polarization direction. Note the color. This is the color parallel to the polarizer. Then rotate the fiber rotating the stage 90 deg. so that the polarization direction is across the fiber. This is the perpendicular position. Again note the color. Both colors must be consistent with standard asbestos minerals in the correct direction for a positive identification of asbestos. If only one of the colors is correct while the other is not, the identification is not positive. If the colors in both directions are bluish-white, the analyst has chosen a matching index oil which is higher than the correct matching oil, e.g. the analyst has used n = 1.620 where chrysotile is present. The next lower oil (Section 3.5.) should be used to prepare another specimen. If the color in both directions is yellow-white to straw-yellow-white, this indicates that the index of the oil is lower than the index of the fiber, e.g. the preparation is in n = 1.550 while anthophyllite is present. Select the next higher oil (Section 3.5.) and prepare another slide. Continue in this fashion until a positive identification of all asbestos species present has been made or all possible asbestos species have been ruled out by negative results in this test. Certain plant fibers can have similar dispersion colors as asbestos. Take care to note and evaluate the morphology of the fibers or remove the plant fibers in pre-preparation. Coating material on the fibers such as carbonate or vinyl may destroy the dispersion color. Usually, there will be some outcropping of fiber which will show the colors sufficient for identification. When this is not the case, treat the sample as described in Section 3.3. and then perform dispersion staining. Some samples will yield to Becke line analysis if they are coated or electron microscopy can be used for identification.

5. References

5.1. Crane, D.T., Asbestos in Air, OSHA method ID160, Revised November 1992.

5.2. Ford, W.E., Dana's Textbook of Mineralogy; Fourth Ed.; John Wiley and Son, New York, 1950, p. vii.

5.3. Selikoff,.I.J., Lee, D.H.K., Asbestos and Disease, Academic Press, New York, 1978, pp. 3, 20.

5.4. Women Inspectors of Factories. Annual Report for 1898, H.M. Statistical Office, London, p. 170 (1898).

5.5. Selikoff,.I.J., Lee, D.H.K., Asbestos and Disease, Academic Press, New York, 1978, pp. 26, 30.

5.6. Campbell, W.J., et al, Selected Silicate Minerals and Their Asbestiform Varieties, United States Department of the Interior, Bureau of Mines, Information Circular 8751, 1977.

5.7. Asbestos, Code of Federal Regulations, 29 CFR 1910.1001 and 29 CFR 1926.58.

5.8. National Emission Standards for Hazardous Air Pollutants; Asbestos NESHAP Revision, Federal Register, Vol. 55, No. 224, 20 November 1990, p. 48410.

5.9. Ross, M. The Asbestos Minerals: Definitions, Description, Modes of Formation, Physical and Chemical Properties and Health Risk to the Mining Community, Nation Bureau of Standards Special Publication, Washington, D.C., 1977.

5.10. Lilis, R., Fibrous Zeolites and Endemic Mesothelioma in Cappadocia, Turkey, J. Occ Medicine, 1981, 23, (8) ,548-550.

5.11. Occupational Exposure to Asbestos -- 1972, U.S. Department of Health Education and Welfare, Public Health Service, Center for Disease Control, National Institute for Occupational Safety and Health, HSM-72-10267.

5.12. Campbell,W.J., et al, Relationship of Mineral Habit to Size Characteristics for Tremolite Fragments and Fibers, United States Department of the Interior, Bureau of Mines, Information Circular 8367, 1979.

5.13. Mefford, D., DCM Laboratory, Denver, private communication, July 1987.

5.14. Deer, W.A., Howie, R.A., Zussman, J., Rock Forming Minerals, Longman, Thetford, UK, 1974.

5.15. Kerr, P.F., Optical Mineralogy; Third Ed. McGraw-Hill, New York, 1959.

5.16. Veblen, D.R. (Ed.), Amphiboles and Other Hydrous Pyriboles -- Mineralogy, Reviews in Mineralogy, Vol 9A, Michigan, 1982, pp 1-102.

5.17. Dixon, W.C., Applications of Optical Microscopy in the Analysis of Asbestos and Quartz, ACS Symposium Series, No. 120, Analytical Techniques in Occupational Health Chemistry, 1979.

5.18. Polarized Light Microscopy, McCrone Research Institute, Chicago, 1976.

5.19. Asbestos Identification, McCrone Research Institute, G&G printers, Chicago, 1987.

5.20. McCrone, W.C., Calculation of Refractive Indices from Dispersion Staining Data, The Microscope, No 37, Chicago, 1989.

5.21. Levadie, B. (Ed.), Asbestos and Other Health Related Silicates, ASTM Technical Publication 834, ASTM, Philadelphia 1982.

5.22. Steel, E. and Wylie, A., Riordan, P.H. (Ed.), Mineralogical Characteristics of Asbestos, Geology of Asbestos Deposits, pp. 93-101, SME-AIME, 1981.

5.23. Zussman, J., The Mineralogy of Asbestos, Asbestos: Properties, Applications and Hazards, pp. 45-67 Wiley, 1979.

Appendix L to 1915.1001 -- Work Practices and Engineering Controls for Automotive Brake and Clutch Inspection, Disassembly, Repair and Assembly -- Mandatory

This mandatory appendix specifies engineering controls and work practices that must be implemented by the employer during automotive brake and clutch inspection, disassembly, repair, and assembly operations. Proper use of these engineering controls and work practices will reduce employees' asbestos exposure below the permissible exposure level during clutch and brake inspection, disassembly, repair, and assembly operations. The employer shall institute engineering controls and work practices using either the method set forth in paragraph [A] or paragraph [B] of this appendix, or any other method which the employer can demonstrate to be equivalent in terms of reducing employee exposure to asbestos as defined and which meets the requirements described in paragraph [C] of this appendix, for those facilities in which no more than 5 pairs of brakes or 5 clutches are inspected, disassembled, reassembled and/or repaired per week, the method set forth in paragraph [D] of this appendix may be used:

[A] Negative Pressure Enclosure/HEPA Vacuum System Method

(1) The brake and clutch inspection, disassembly, repair, and assembly operations shall be enclosed to cover and contain the clutch or brake assembly and to prevent the release of asbestos fibers into the worker's breathing zone.

(2) The enclosure shall be sealed tightly and thoroughly inspected for leaks before work begins on brake and clutch inspection, disassembly, repair, and assembly.

(3) The enclosure shall be such that the worker can clearly see the operation and shall provide impermeable sleeves through which the worker can handle the brake and clutch inspection, disassembly, repair and assembly. The integrity of the sleeves and ports shall be examined before work begins.

(4) A HEPA-filtered vacuum shall be employed to maintain the enclosure under negative pressure throughout the operation. Compressed-air may be used to remove asbestos fibers or particles from the enclosure.

(5) The HEPA vacuum shall be used first to loosen the asbestos containing residue from the brake and clutch parts and then to evacuate the loosened asbestos containing material from the enclosure and capture the material in the vacuum filter.

(6) The vacuum's filter, when full, shall be first wetted with a fine mist of water, then removed and placed immediately in an impermeable container, labeled according to paragraph (j)(2)(ii) of this section and disposed of according to paragraph (k) of this section.

(7) Any spills or releases of asbestos containing waste material from inside of the enclosure or vacuum hose or vacuum filter shall be immediately cleaned up and disposed of according to paragraph (k) of the section.

[B] Low Pressure/Wet Cleaning Method

(1) A catch basin shall be placed under the brake assembly, positioned to avoid splashes and spills.

(2) The reservoir shall contain water containing an organic solvent or wetting agent. The flow of liquid shall be controlled such that the brake assembly is gently flooded to prevent the asbestos-containing brake dust from becoming airborne.

(3) The aqueous solution shall be allowed to flow between the brake drum and brake support before the drum is removed.

(4) After removing the brake drum, the wheel hub and back of the brake assembly shall be thoroughly wetted to suppress dust.

(5) The brake support plate, brake shoes and brake components used to attach the brake shoes shall be thoroughly washed before removing the old shoes.

(6) In systems using filters, the filters, when full, shall be first wetted with a fine mist of water, then removed and placed immediately in an impermeable container, labeled according to paragraph (j)(2)(ii) of this section and disposed of according to paragraph (k) of this section.

(7) Any spills of asbestos-containing aqueous solution or any asbestos-containing waste material shall be cleaned up immediately and disposed of according to paragraph (k) of this section.

(8) The use of dry brushing during low pressure/wet cleaning operations is prohibited.

[C] Equivalent Methods

An equivalent method is one which has sufficient written detail so that it can be reproduced and has been demonstrated that the exposures resulting from the equivalent method are equal to or less than the exposures which would result from the use of the method described in paragraph [A] of this appendix. For purposes of making this comparison, the employer shall assume that exposures resulting from the use of the method described in paragraph [A] of this appendix shall not exceed 0.004 f/cc, as measured by the OSHA reference method and as averaged over at least 18 personal samples.

[D] Wet Method

(1) A spray bottle, hose nozzle, or other implement capable of delivering a fine mist of water or amended water or other delivery system capable of delivering water at low pressure, shall be used to first thoroughly wet the brake and clutch parts. Brake and clutch components shall then be wiped clean with a cloth.

(2) The cloth shall be placed in an impermeable container, labelled according to paragraph (j)(2)(ii) of this section and then disposed of according to paragraph (k) of this section, or the cloth shall be laundered in a way to prevent the release of asbestos fibers in excess of 0.1 fiber per cubic centimeter of air.

(3) Any spills of solvent or any asbestos containing waste material shall be cleaned up immediately according to paragraph (k) of this section.

(4) The use of dry brushing during the wet method operations is prohibited.

Construction

PART 1926 -- [AMENDED]

1. The authority citation of subpart Z of 29 CFR part 1926 continues to read as follows:

Authority: Sections 6 and 8, Occupational Safety and Health Act, 29 U.S.C. 655, 657; Secretary of Labor's Orders Nos. 12-71 (36 FR 8754), 8-76 (41 FR 25059), 9-83 (48 FR 35736) or 1-90 (55 FR 9033) as applicable; and 29 CFR part 1911.

Section 1926.1102 not issued under 29 U.S.C. 655 or 29 CFR part 1911; also issued under 5 U.S.C. 653.

Section 1926.1103 through 1926.1118 also issued under 29 U.S.C. 6653. Section 1926.1128 also issued under 29 U.S.C. 653. Section 1926.1145 and 1926.1147 also issued under 29 U.S.C. 653. Section 1926.1148 also issued under 29 U.S.C. 653.

2. Section 1926.58 Asbestos, tremolite, anthophyllite, and actinolite is redesignated as Sec. 1926.1101 Asbestos and Sec. 1926.58 is reserved.

3. Section 1926.1101 is amended by revising the section heading and paragraphs (a) through (p) (all the text preceding the appendices) and by adding paragraph (q) to read as follows:

1926.1101 Asbestos.

(a) Scope and application. This section regulates asbestos exposure in all work as defined in 29 CFR 1910.12(b), including but not limited to the following:

(1) Demolition or salvage of structures where asbestos is present;

(2) Removal or encapsulation of materials containing asbestos;

(3) Construction, alteration, repair, maintenance, or renovation of structures, substrates, or portions thereof, that contain asbestos;

(4) Installation of products containing asbestos;

(5) Asbestos spill/emergency cleanup; and

(6) Transportation, disposal, storage, containment of and housekeeping activities involving asbestos or products containing asbestos, on the site or location at which construction activities are performed.

(7) Coverage under this standard shall be based on the nature of the work operation involving asbestos exposure.

(b) Definitions. "Aggressive method" means removal or disturbance of building material by sanding, abrading, grinding or other method that breaks, crumbles, or disintegrates intact ACM.

"Amended water" means water to which surfactant (wetting agent) has been added to increase the ability of the liquid to penetrate ACM.

"Asbestos" includes chrysotile, amosite, crocidolite, tremolite asbestos, anthophyllite asbestos, actinolite asbestos, and any of these minerals that has been chemically treated and/or altered. For purposes of this standard, "asbestos" includes PACM, as defined below.

"Asbestos-containing material (ACM)", means any material containing more than one percent asbestos.

"Assistant Secretary" means the Assistant Secretary of Labor for Occupational Safety and Health, U.S. Department of Labor, or designee.

"Authorized person" means any person authorized by the employer and required by work duties to be present in regulated areas.

"Building/facility owner" is the legal entity, including a lessee, which exercises control over management and record keeping functions relating to a building and/or facility in which activities covered by this standard take place.

"Certified Industrial Hygienist (CIH)" means one certified in the comprehensive practice of industrial hygiene by the American Board of Industrial Hygiene.

"Class I asbestos work" means activities involving the removal of TSI and surfacing ACM and PACM.

"Class II asbestos work" means activities involving the removal of ACM which is not thermal system insulation or surfacing material. This includes, but is not limited to, the removal of asbestos-containing wallboard, floor tile and sheeting, roofing and siding shingles, and construction mastics.

"Class III asbestos work" means repair and maintenance operations, where "ACM", including thermal system insulation and surfacing material, is likely to be disturbed.

"Class IV asbestos work" means maintenance and custodial activities during which employees contact ACM and PACM and activities to clean up waste and debris containing ACM and PACM.

"Clean room" means an uncontaminated room having facilities for the storage of employees' street clothing and uncontaminated materials and equipment.

"Closely resemble" means that the major workplace conditions which have contributed to the levels of historic asbestos exposure, are no more protective than conditions of the current workplace.

"Competent person" means, in addition to the definition in 29 CFR 1926.32 (f), one who is capable of identifying existing asbestos hazards in the workplace and selecting the appropriate control strategy for asbestos exposure, who has the authority to take prompt corrective measures to eliminate them, as specified in 29 CFR 1926.32(f): in addition, for Class I and Class II work who is specially trained in a training course which meet the criteria of EPA's Model Accreditation Plan (40 CFR 763) for project designer or supervisor, or its equivalent and, for Class II and Class IV work, who is trained in an operations and maintenance (O&M) course developed by EPA [40 CFR 763.92 (a)(2)].

"Critical barrier" means one or more layers of plastic sealed over all openings into a work area or any other similarly placed physical barrier sufficient to prevent airborne asbestos in a work area from migrating to an adjacent area.

"Decontamination area" means an enclosed area adjacent and connected to the regulated area and consisting of an equipment room, shower area, and clean room, which is used for the decontamination of workers, materials, and equipment that are contaminated with asbestos.

"Demolition" means the wrecking or taking out of any load-supporting structural member and any related razing, removing, or stripping of asbestos products.

"Director" means the Director, National Institute for Occupational Safety and Health, U.S. Department of Health and Human Services, or designee.

"Disturbance" means contact which releases fibers from ACM or PACM or debris containing ACM or PACM. This term includes activities that disrupt the matrix of ACM or PACM, render ACM or PACM friable, or generate visible debris. Disturbance includes cutting away small amounts of ACM and PACM, no greater than the amount which can be contained in one standard sized glove bag or waste bag in order to access a building component. In no event shall the amount of ACM or PACM so disturbed exceed that which can be contained in one glove bag or waste bag which shall not exceed 60 inches in length and width.

"Employee exposure" means that exposure to airborne asbestos that would occur if the employee were not using respiratory protective equipment.

"Equipment room (change room)" means a contaminated room located within the decontamination area that is supplied with impermeable bags or containers for the disposal of contaminated protective clothing and equipment.

"Fiber" means a particulate form of asbestos, 5 micrometers or longer, with a length-to-diameter ratio of at least 3 to 1.

"Glovebag" means an impervious plastic bag-like enclosure affixed around an asbestos-containing material, with glove-like appendages through which material and tools may be handled.

"High-efficiency particulate air (HEPA) filter" means a filter capable of trapping and retaining at least 99.97 percent of all mono-dispersed particles of 0.3 micrometers in diameter.

"Homogeneous area" means an area of surfacing material or thermal system insulation that is uniform in color and texture.

"Industrial hygienist" means a professional qualified by education, training, and experience to anticipate, recognize, evaluate and develop controls for occupational health hazards.

"Intact" means that the ACM has not crumbled, been pulverized, or otherwise deteriorated so that it is no longer likely to be bound with its matrix.

"Modification for purposes of paragraph (g)(6)(ii)," means a changed or altered procedure, material or component of a control system, which replaces a procedure, material or component of a required system. Omitting a procedure or component, or reducing or diminishing the stringency or strength of a material or component of the control system is not a "modification" for purposes of paragraph (g)(6)(ii) of this section.

"Negative Initial Exposure Assessment" means a demonstration by the employer, which complies with the criteria in paragraph (f)(2)(iii) of this section, that employee exposure during an operation is expected to be consistently below the PELs.

"PACM" means "presumed asbestos containing material". "Presumed Asbestos Containing Material" means thermal system insulation and surfacing material found in buildings constructed no later than 1980. The designation of a material as "PACM" may be rebutted pursuant to paragraph (k)(4) of this section.

"Project Designer" means a person who has successfully completed the training requirements for an abatement project designer established by 40 U.S.C. Sec. 763.90(g).

"Regulated area" means: an area established by the employer to demarcate areas where Class I, II, and III asbestos work is conducted, and any adjoining area where debris and waste from such asbestos work accumulate; and a work area within which airborne concentrations of asbestos, exceed or there is a reasonable possibility they may exceed the permissible exposure limit. Requirements for regulated areas are set out in paragraph (e)(6) of this section.

"Removal" means all operations where ACM and/or PACM is taken out or stripped from structures or substrates, and includes demolition operations.

"Renovation" means the modifying of any existing structure, or portion thereof.

"Repair" means overhauling, rebuilding, reconstructing, or reconditioning of structures or substrates, including encapsulation or other repair of ACM or PACM attached to structures or substrates.

"Surfacing material" means material that is sprayed, troweled-on or otherwise applied to surfaces (such as acoustical plaster on ceilings and fireproofing materials on structural members, or other materials on surfaces for acoustical, fireproofing, and other purposes).

"Surfacing ACM" means surfacing material which contains more than 1% asbestos.

"Thermal system insulation (TSI)" means ACM applied to pipes, fittings, boilers, breeching, tanks, ducts or other structural components to prevent heat loss or gain.

"Thermal system insulation ACM" is thermal system insulation which contains more than 1% asbestos.

(c) Permissible exposure limits (PELS) -- (1) Time-weighted average limit (TWA). The employer shall ensure that no employee is exposed to an airborne concentration of asbestos in excess of 0.1 fiber per cubic centimeter of air as an eight (8) hour time-weighted average (TWA), as determined by the method prescribed in Appendix A of this section, or by an equivalent method.

(2) Excursion limit. The employer shall ensure that no employee is exposed to an airborne concentration of asbestos in excess of 1.0 fiber per cubic centimeter of air (1 f/cc) as averaged over a sampling period of thirty (30) minutes, as determined by the method prescribed in Appendix A of this section, or by an equivalent method.

(d) Multi-employer worksites. (1) On multi-employer worksites, an employer performing work requiring the establishment of a regulated area shall inform other employers on the site of the nature of the employer's work with asbestos and/or PACM, of the existence of and requirements pertaining to regulated areas, and the measures taken to ensure that employees of such other employers are not exposed to asbestos.

(2) Asbestos hazards at a multi-employer work site shall be abated by the contractor who created or controls the source of asbestos contamination. For example, if there is a significant breach of an enclosure containing Class I work, the employer responsible for erecting the enclosure shall repair the breach immediately.

(3) In addition, all employers of employees exposed to asbestos hazards shall comply with applicable protective provisions to protect their employees. For example, if employees working immediately adjacent to a Class I asbestos job are exposed to asbestos due to the inadequate containment of such job, their employer shall either remove the employees from the area until the enclosure breach is repaired; or perform an initial exposure assessment pursuant to (f)(1) of this section.

(4) All employers of employees working adjacent to regulated areas established by another employer on a multi-employer work-site, shall take steps on a daily basis to ascertain the integrity of the enclosure and/or the effectiveness of the control method relied on by the primary asbestos contractor to assure that asbestos fibers do not migrate to such adjacent areas.

(5) All general contractors on a construction project which includes work covered by this standard shall be deemed to exercise general supervisory authority over the work covered by this standard, even though the general contractor is not qualified to serve as the asbestos "competent person" as defined by paragraph (b) of this section. As supervisor of the entire project, the general contractor shall ascertain whether the asbestos contractor is in compliance with this standard, and shall require such contractor to come into compliance with this standard when necessary.

(e) Regulated areas -- (1) All Class I, II and III asbestos work shall be conducted within regulated areas. All other operations covered by this standard shall be conducted within a regulated area where airborne concentrations of asbestos exceed, or there is a reasonable possibility they may exceed a PEL. Regulated areas shall comply with the requirements of paragraphs (2), (3),(4) and (5) of this section.

(2) Demarcation. The regulated area shall be demarcated in any manner that minimizes the number of persons within the area and protects persons outside the area from exposure to airborne concentrations of asbestos. Where critical barriers or negative pressure enclosures are used, they may demarcate the regulated area. Signs shall be provided and displayed pursuant to the requirements of paragraph (k)(6) of this section.

(3) Access. Access to regulated areas shall be limited to authorized persons and to persons authorized by the Act or regulations issued pursuant thereto.

(4) Respirators. All persons entering a regulated area where employees are required pursuant to paragraph (h)(2) of this section to wear respirators shall be supplied with a respirator selected in accordance with paragraph (h)(2) of this section.

(5) Prohibited activities. The employer shall ensure that employees do not eat, drink, smoke, chew tobacco or gum, or apply cosmetics in the regulated area.

(6) Competent Persons. The employer shall ensure that all asbestos work performed within regulated areas is supervised by a competent person, as defined in paragraph (b) of this section. The duties of the competent person are set out in paragraph (o) of this section.

(f) Exposure assessments and monitoring -- (1) General monitoring criteria. (i) Each employer who has a workplace of work operation where exposure monitoring is required under this section shall perform monitoring to determine accurately the airborne concentrations of asbestos to which employees may be exposed.

(ii) Determinations of employee exposure shall be made from breathing zone air samples that are representative of the 8-hour TWA and 30-minute short-term exposures of each employee.

(iii) Representative 8-hour TWA employee exposure shall be determined on the basis of one or more samples representing full-shift exposure for employees in each work area. Representative 30-minute short-term employee exposures shall be determined on the basis of one or more samples representing 30 minute exposures associated with operations that are most likely to produce exposures above the excursion limit for employees in each work area.

(2) Initial Exposure Assessment. (i) Each employer who has a workplace or work operation covered by this standard shall ensure that a "competent person" conducts an exposure assessment immediately before or at the initiation of the operation to ascertain expected exposures during that operation or workplace.

The assessment must be completed in time to comply with requirements which are triggered by exposure data or the lack of a "negative exposure assessment," and to provide information necessary to assure that all control systems planned are appropriate for that operation and will work properly.

(ii) Basis of Initial Exposure Assessment: The initial exposure assessment shall be based on data derived from the following sources:

(A) If feasible, the employer shall monitor employees and base the exposure assessment on the results of exposure monitoring which is conducted pursuant to the criteria in paragraph (f)(2)(iii) of this section.

(B) In addition, the assessment shall include consideration of all observations, information or calculations which indicate employee exposure to asbestos, including any previous monitoring conducted in the workplace, or of the operations of the employer which indicate the levels of airborne asbestos likely to be encountered on the job. However, the assessment may conclude that exposures are likely to be consistently below the PELs only as a conclusion of a "negative exposure assessment" conducted pursuant to (f)(2)(iii) of this section.

(C) For Class I asbestos work, until the employer conducts exposure monitoring and documents that employees on that job will not be exposed in excess of the PELs, or otherwise makes a negative exposure assessment pursuant to paragraph (f)(2)(iii) of this section, the employer shall presume that employees are exposed in excess of the TWA and excursion limit.

(iii) Negative Exposure Assessment: For any one specific asbestos job which will be performed by employees who have been trained in compliance with the standard, the employer may demonstrate that employee exposures will be below the PELs by data which conform to the following criteria;

(A) Objective data demonstrating that the product or material containing asbestos minerals or the activity involving such product or material cannot release airborne fibers in concentrations exceeding the TWA and excursion limit under those work conditions having the greatest potential for releasing asbestos; or (B) Where the employer has monitored prior asbestos jobs for the PEL and the excursion limit within 12 months of the current or projected job, the monitoring and analysis were performed in compliance with the asbestos standard in effect; and the data were obtained during work operations conducted under workplace conditions "closely resembling" the processes, type of material, control methods, work practices, and environmental conditions used and prevailing in the employer's current operations, the operations were conducted by employees whose training and experience are no more extensive than that of employees performing the current job, and these data show that under the conditions prevailing and which will prevail in the current workplace there is a high degree of certainty that employee exposures will not exceed the TWA and excursion limit; or (C) The results of initial exposure monitoring of the current job made from breathing zone air samples that are representative of the 8- hour TWA and 30-minute short-term exposures of each employee covering operations which are most likely during the performance of the entire asbestos job to result in exposures over the PELs.

(3) Periodic monitoring. (i) Class I and II operations. The employer shall conduct daily monitoring that is representative of the exposure of each employee who is assigned to work within a regulated area who is performing Class I or II work, unless the employer pursuant to (f)(2)(iii) of this section, has made a negative exposure assessment for the entire operation.

(ii) All operations under the standard other than Class I and II operations. The employer shall conduct periodic monitoring of all work where exposures are expected to exceed a PEL, at intervals sufficient to document the validity of the exposure prediction.

(iii) Exception: When all employees required to be monitored daily are equipped with supplied-air respirators operated in the positive- pressure mode, the employer may dispense with the daily monitoring required by this paragraph. However, employees performing Class I work using a control method which is not listed in paragraph (g)(4)(i), (ii), or (iii) of this section or using a modification of a listed control method, shall continue to be monitored daily even if they are equipped with supplied-air respirators.

(4)(i) Termination of monitoring. If the periodic monitoring required by paragraph (f)(3) of this section reveals that employee exposures, as indicated by statistically reliable measurement, are below the permissible exposure limit and excursion limit the employer may discontinue monitoring for those employees whose exposures are represented by such monitoring.

(ii) Additional monitoring. Notwithstanding the provisions of paragraph (f)(2) and (3), and (f)(4) of this section, the employer shall institute the exposure monitoring required under paragraph (f)(3) of this section whenever there has been a change in process, control equipment, personnel or work practices that may result in new or additional exposures above the permissible exposure limit and/or excursion limit or when the employer has any reason to suspect that a change may result in new or additional exposures above the permissible exposure limit and/or excursion limit. Such additional monitoring is required regardless of whether a "negative exposure assessment" was previously produced for a specific job.

(5) Observation of monitoring. (i) The employer shall provide affected employees and their designated representatives an opportunity to observe any monitoring of employee exposure to asbestos conducted in accordance with this section.

(ii) When observation of the monitoring of employee exposure to asbestos requires entry into an area where the use of protective clothing or equipment is required, the observer shall be provided with and be required to use such clothing and equipment and shall comply with all other applicable safety and health procedures.

(g) Methods of compliance -- (1) Engineering controls and work practices for all operations covered by this section. The employer shall use the following engineering controls and work practices in all operations covered by this section, regardless of the levels of exposure:

(i) Vacuum cleaners equipped with HEPA filters to collect all debris and dust containing ACM or PACM; and, (ii) Wet methods, or wetting agents, to control employee exposures during asbestos handling, mixing, removal, cutting, application, and cleanup, except where employers demonstrate that the use of wet methods is infeasible due to for example, the creation of electrical hazards, equipment malfunction, and, in roofing, slipping hazards; and

(iii) Prompt clean-up and disposal of wastes and debris contaminated with asbestos in leak-tight containers.

(2) In addition to the requirements of paragraph (g)(1) of this section, the employer shall use the following control methods to achieve compliance with the TWA permissible exposure limit and excursion limit prescribed by paragraph (c) of this section;

(i) Local exhaust ventilation equipped with HEPA filter dust collection systems;

(ii) Enclosure or isolation of processes producing asbestos dust;

(iii) Ventilation of the regulated area to move contaminated air away from the breathing zone of employees and toward a filtration or collection device equipped with a HEPA filter;

(iv) Use of other work practices and engineering controls that the Assistant Secretary can show to be feasible.

(v) Wherever the feasible engineering and work practice controls described above are not sufficient to reduce employee exposure to or below the permissible exposure limit and/or excursion limit prescribed in paragraph (c) of this section, the employer shall use them to reduce employee exposure to the lowest levels attainable by these controls and shall supplement them by the use of respiratory protection that complies with the requirements of paragraph (h) of this section.

(3) Prohibitions. The following work practices and engineering controls shall not be used for work related to asbestos or for work which disturbs ACM or PACM, regardless of measured levels of asbestos exposure or the results of initial exposure assessments:

(i) High-speed abrasive disc saws that are not equipped with point of cut ventilator or enclosures with HEPA filtered exhaust air.

(ii) Compressed air used to remove asbestos, or materials containing asbestos, unless the compressed air is used in conjunction with an enclosed ventilation system designed to capture the dust cloud created by the compressed air.

(iii) Dry sweeping, shoveling or other dry clean-up of dust and debris containing ACM and PACM.

(iv) Employee rotation as a means of reducing employee exposure to asbestos.

(4) Class I Requirements. In addition to the provisions of paragraphs (g)(1) and (2) of this section, the following engineering controls and work practices and procedures shall be used.

(i) All Class I work, including the installation and operation of the control system shall be supervised by a competent person as defined in paragraph (b) of this section;

(ii) For all Class I jobs involving the removal of more than 25 linear or 10 square feet of thermal system insulation or surfacing material; for all other Class I jobs, where the employer cannot produce a negative exposure assessment pursuant to paragraph (f)(2)(iii) of this section, or where employees are working in areas adjacent to the regulated area, while the Class I work is being performed, the employer shall use one of the following methods to ensure that airborne asbestos does not migrate from the regulated area:

(A) Critical barriers shall be placed over all openings to the regulated area: or

(B) The employer shall use another barrier or isolation method which prevents the migration of airborne asbestos from the regulated area, as verified by perimeter area surveillance during each work shift at each boundary of the regulated area, showing no visible asbestos dust; and perimeter area monitoring showing that clearance levels contained in 40 CFR Part 763, Subpt. E, of the EPA Asbestos in Schools Rule are met, or that perimeter area levels, measured by (PCM) are no more than background levels representing the same area before the asbestos work began. The results of such monitoring shall be made known to the employer no later than 24 hours from the end of the work shift represented by such monitoring.

(iii) For all Class I jobs, HVAC systems shall be isolated in the regulated area by sealing with a double layer of 6 mil plastic or the equivalent;

(iv) For all Class I jobs, impermeable dropcloths shall be placed on surfaces beneath all removal activity;

(v) For all Class I jobs, all objects within the regulated area shall be covered with impermeable dropcloths or plastic sheeting which is secured by duct tape or an equivalent.

(vi) For all Class I jobs where the employer cannot produce a negative exposure assessment, or where exposure monitoring shows that a PEL is exceeded, the employer shall ventilate the regulated area to move contaminated air away from the breathing zone of employees toward a HEPA filtration or collection device.

(5) Specific control methods for Class I work. In addition, Class I asbestos work shall be performed using one or more of the following control methods pursuant to the limitations stated below:

(i) Negative Pressure Enclosure (NPE) systems: NPE systems shall be used where the configuration of the work area does not make the erection of the enclosure infeasible, with the following specifications and work practices.

(A) Specifications:

(1) The negative pressure enclosure (NPE) may be of any configuration,

(2) At least 4 air changes per hour shall be maintained in the NPE,

(3) A minimum of -0.02 column inches of water pressure differential, relative to outside pressure, shall be maintained within the NPE as evidenced by manometric measurements,

(4) The NPE shall be kept under negative pressure throughout the period of its use, and

(5) Air movement shall be directed away from employees performing asbestos work within the enclosure, and toward a HEPA filtration or a collection device.

(B) Work Practices:

(1) Before beginning work within the enclosure and at the beginning of each shift, the NPE shall be inspected for breaches and smoke-tested for leaks, and any leaks sealed.

(2) Electrical circuits in the enclosure shall be deactivated, unless equipped with ground-fault circuit interrupters.

(ii) Glove bag systems shall be used to remove PACM and/or ACM from straight runs of piping with the following specifications and work practices.

(A) Specifications:

(1) Glovebags shall be made of 6 mil thick plastic and shall be seamless at the bottom.

(2) [Reserved]

(B) Work Practices:

(1) Each glovebag shall be installed so that it completely covers the circumference of pipe or other structure where the work is to be done.

(2) Glovebags shall be smoke-tested for leaks and any leaks sealed prior to use.

(3) Glovebags may be used only once and may not be moved. (4) Glovebags shall not be used on surfaces whose temperature exceeds 150 deg..

(5) Prior to disposal, glovebags shall be collapsed by removing air within them using a HEPA vacuum.

(6) Before beginning the operation, loose and friable material adjacent to the glovebag/box operation shall be wrapped and sealed in two layers of six mil plastic or otherwise rendered intact, (7) Where system uses attached waste bag, such bag shall be connected to collection bag using hose or other material which shall withstand pressure of ACM waste and water without losing its integrity:

(8) Sliding valve or other device shall separate waste bag from hose to ensure no exposure when waste bag is disconnected:

(9) At least two persons shall perform Class I glovebag removals.

(iii) Negative Pressure Glove Bag Systems. Negative pressure glove bag systems shall be used to remove ACM or PACM from piping.

(A) Specifications: In addition to specifications for glove bag systems above, negative pressure glove bag systems shall attach HEPA vacuum systems or other devices to bag to prevent collapse during removal.

(B) Work Practices: (1) The employer shall comply with the work practices glove bag systems in paragraph (g)(5)(ii)(B)(2) of this section.

(2) The HEPA vacuum cleaner or other device used to prevent collapse of bag during removal shall run continually during the operation.

(3) Where a separate waste bag is used along with a collection bag and discarded after one use, the collection bag may be reused if rinsed clean with amended water before reuse.

(iv) Negative Pressure Glove Box Systems: Negative pressure glove boxes shall be used to remove ACM or PACM from pipe runs with the following specifications and work practices.

(A) Specifications:

(1) Glove boxes shall be constructed with rigid sides and made from metal or other material which can withstand the weight of the ACM and PACM and water used during removal:

(2) A negative pressure generator shall be used to create negative pressure in system:

(3) An air filtration unit shall be attached to the box:

(4) The box shall be fitted with gloved apertures:

(5) An aperture at the base of the box shall serve as a bagging outlet for waste ACM and water:

(6) A back-up generator shall be present on site:

(7) Waste bags shall consist of 6 mil thick plastic double-bagged before they are filled or plastic thicker than 6 mil.

(B) Work practices:

(1) At least two persons shall perform the removal:

(2) The box shall be smoke tested prior to each use:

(3) Loose or damaged ACM adjacent to the box shall be wrapped and sealed in two layers of 6 mil plastic prior to the job, or otherwise made intact prior to the job.

(4) A HEPA filtration system shall be used to maintain pressure barrier in box.

(v) Water Spray Process System. A water spray process system may be used for removal of ACM and PACM from cold line piping if, employees carrying out such process have completed a 40-hour separate training course in its use, in addition to training required for employees performing Class I work. The system shall meet the following specifications and shall be performed by employees using the following work practices.

(A) Specifications:

(1) Piping shall be surrounded on 3 sides by rigid framing,

(2) A 360 degree water spray, delivered through nozzles supplied by a high pressure separate water line, shall be formed around the piping.

(3) The spray shall collide to form a fine aerosol which provides a liquid barrier between workers and the ACM and PACM.

(B) Work Practices:

(1) The system shall be run for at least 10 minutes before removal begins.

(2) All removal shall take place within the water barrier.

(3) The system shall be operated by at least three persons, one of whom shall not perform removal, but shall check equipment, and ensure proper operation of the system.

(4) After removal, the ACM and PACM shall be bagged while still inside the water barrier.

(vi) A small walk-in enclosure which accommodates no more than two persons (mini-enclosure) may be used if the disturbance or removal can be completely contained by the enclosure with the following specifications and work practices.

(A) Specifications:

(1) The fabricated or job-made enclosure shall be constructed of 6 mil plastic or equivalent:

(2) The enclosure shall be placed under negative pressure by means of a HEPA filtered vacuum or similar ventilation unit:

(B) Work practices:

(1) Before use, the minienclosure shall be inspected for leaks and smoke tested to detect breaches, and breaches sealed.

(2) Before reuse, the interior shall be completely washed with amended water and HEPA-vacuumed..

(3) During use air movement shall be directed away from the employee's breathing zone within the minienclosure.

(6) Alternative control methods for Class I work. Class I work may be performed using a control method which is not referenced in paragraph (g)(5) of this section, or which modifies a control method referenced in paragraph (g)(5)of this section, if the following provisions are complied with:

(i) The control method shall enclose, contain or isolate the processes or source of airborne asbestos dust, or otherwise capture or redirect such dust before it enters the breathing zone of employees.

(ii) A certified industrial hygienist or licensed professional engineer who is also qualified as a project designer as defined in paragraph (b) of this section, shall evaluate the work area, the projected work practices and the engineering controls and shall certify in writing that the planned control method is adequate to reduce direct and indirect employee exposure to below the PELs under worst-case conditions of use, and that the planned control method will prevent asbestos contamination outside the regulated area, as measured by clearance sampling which meets the requirements of EPA's Asbestos in Schools rule issued under AHERA, or perimeter monitoring which meets the criteria in paragraph (g)(4)(i)(B)(2) of this section.

(A) Where the TSI or surfacing material to be removed is 25 linear or 10 square feet or less , the evaluation required in paragraph (g)(6) of this section may be performed by a "competent person", and may omit consideration of perimeter or clearance monitoring otherwise required.

(B) The evaluation of employee exposure required in paragraph (g)(6) of this section, shall include and be based on sampling and analytical data representing employee exposure during the use of such method under worst-case conditions and by employees whose training and experience are equivalent to employees who are to perform the current job.

(iii) Before work which involves the removal of more than 25 linear or 10 square feet of thermal system insulation or surfacing material is begun using an alternative method which has been the subject of a paragraph (g)(6) required evaluation and certification, the employer shall send a copy of such evaluation and certification to the national office of OSHA, Office of Technical Support, Room N3653, 200 Constitution Avenue, NW, Washington, DC 20210.

(7) Work Practices and Engineering Controls for Class II work. (i) All Class II work, shall be supervised by a competent person as defined in paragraph (b) of this section.

(ii) For all indoor Class II jobs, where the employer has not produced a negative exposure assessment pursuant to paragraph (f)(4)(iii) of this section, or where during the job changed conditions indicate there may be exposure above the PEL or where the employer does not remove the ACM in a substantially intact state, the employer shall use one of the following methods to ensure that airborne asbestos does not migrate from the regulated area;

(A) Critical barriers shall be placed over all openings to the regulated area; or, (B) The employer shall use another barrier or isolation method which prevents the migration of airborne asbestos from the regulated area, as verified by perimeter area monitoring or clearance monitoring which meets the criteria set out in paragraph (g)(4)(i)(B)(2) of this section.

(iii) Impermeable dropcloths shall be placed on surfaces beneath all removal activity;

(iv) All Class II asbestos work shall be performed using the work practices and requirements set out above in paragraph (g)(3)(i) through (v) of this section.

(8) Additional Controls for Class II work. Class II asbestos work shall also be performed by complying with the work practices and controls designated for each type of asbestos work to be performed, set out in this paragraph. Where more than one control method may be used for a type of asbestos work, the employer may choose one or a combination of designated control methods. Class II work also may be performed using a method allowed for Class I work, except that glove bags and glove boxes are allowed if they fully enclose the Class II material to be removed.

(i) For removing vinyl and asphalt flooring materials which contain ACM or for which in buildings constructed no later than 1980, the employer has not verified the absence of ACM pursuant to paragraph (g)(8)(i)(I) of this section. The employer shall ensure that employees comply with the following work practices and that employees are trained in these practices pursuant to paragraph (k)(8):

(A) Flooring or its backing shall not be sanded.

(B) Vacuums equipped with HEPA filter, disposable dust bag, and metal floor tool (no brush) shall be used to clean floors.

(C) Resilient sheeting shall be removed by cutting with wetting of the snip point and wetting during delamination. Rip-up of resilient sheet floor material is prohibited.

(D) All scraping of residual adhesive and/or backing shall be performed using wet methods.

(E) Dry sweeping is prohibited.

(F) Mechanical chipping is prohibited unless performed in a negative pressure enclosure which meets the requirements of paragraph (g)(5)(iv) of this section.

(G) Tiles shall be removed intact, unless the employer demonstrates that intact removal is not possible.

(H) When tiles are heated and can be removed intact, wetting may be omitted.

(I) Resilient flooring material including associated mastic and backing shall be assumed to be asbestos-containing unless an industrial hygienist determines that it is asbestos-free using recognized analytical techniques.

(ii) For removing roofing material which contains ACM the employer shall ensure that the following work practices are followed:

(A) Roofing material shall be removed in an intact state to the extent feasible.

(B) Wet methods shall be used where feasible.

(C) Cutting machines shall be continuously misted during use, unless a competent person determines that misting substantially decreases worker safety.

(D) All loose dust left by the sawing operation must be HEPA vacuumed immediately.

(E) Unwrapped or unbagged roofing material shall be immediately lowered to the ground via covered, dust-tight chute, crane or hoist, or placed in an impermeable waste bag or wrapped in plastic sheeting and lowered to ground no later than the end of the work shift.

(F) Upon being lowered, unwrapped material shall be transferred to a closed receptacle in such manner so as to preclude the dispersion of dust.

(G) Roof level heating and ventilation air intake sources shall be isolated or the ventilation system shall be shut down.

(iii) When removing cementitious asbestos-containing siding and shingles or transite panels containing ACM, the employer shall ensure that the following work practices are followed:

(A) Cutting, abrading or breaking siding, shingles, or transite panels, shall be prohibited unless the employer can demonstrate that methods less likely to result in asbestos fiber release cannot be used.

(B) Each panel or shingle shall be sprayed with amended water prior to removal.

(C) Unwrapped or unbagged panels or shingles shall be immediately lowered to the ground via covered dust-tight chute, crane or hoist, or placed in an impervious waste bag or wrapped in plastic sheeting and lowered to the ground no later than the end of the work shift.

(D) Nails shall be cut with flat, sharp instruments.

(iv) When removing gaskets containing ACM, the employer shall ensure that the following work practices are followed:

(A) If a gasket is visibly deteriorated and unlikely to be removed intact, removal shall be undertaken within a glovebag as described in paragraph (g)(5)(ii) of this section.

(B) The gasket shall be thoroughly wetted with amended water prior to its removal.

(C) The wet gasket shall be immediately placed in a disposal container.

(D) Any scraping to remove residue must be performed wet.

(v) When performing any other Class II removal of asbestos containing material for which specific controls have not been listed in paragraph (g)(8)(iv)(A) through (D) of this section, the employer shall ensure that the following work practices are complied with.

(A) The material shall be thoroughly wetted with amended water prior and during its removal.

(B) The material shall be removed in an intact state unless the employer demonstrates that intact removal is not possible.

(C) Cutting, abrading or breaking the material shall be prohibited unless the employer can demonstrate that methods less likely to result in asbestos fiber release are not feasible.

(D) Asbestos-containing material removed, shall be immediately bagged or wrapped, or kept wetted until transferred to a closed receptacle, no later than the end of the work shift.

(vi) Alternative Work Practices and Controls. Instead of the work practices and controls listed in paragraph (g)(8)(i) through (v) of this section, the employer may use different or modified engineering and work practice controls if the following provisions are complied with.

(A) The employer shall demonstrate by data representing employee exposure during the use of such method under conditions which closely resemble the conditions under which the method is to be used, that employee exposure will not exceed the PELs under any anticipated circumstances.

(B) A competent person shall evaluate the work area, the projected work practices and the engineering controls, and shall certify in writing, that the different or modified controls are adequate to reduce direct and indirect employee exposure to below the PELs under all expected conditions of use and that the method meets the requirements of this standard. The evaluation shall include and be based on data representing employee exposure during the use of such method under conditions which closely resemble the conditions under which the method is to be used for the current job, and by employees whose training and experience are equivalent to employees who are to perform the current job.

(9) Work Practices and Engineering Controls for Class III asbestos work. Class III asbestos work shall be conducted using engineering and work practice controls which minimize the exposure to employees performing the asbestos work and to bystander employees.

(i) The work shall be performed using wet methods.

(ii) To the extent feasible, the work shall be performed using local exhaust ventilation.

(iii) Where the disturbance involves drilling, cutting, abrading, sanding, chipping, breaking, or sawing of thermal system insulation or surfacing material, the employer shall use impermeable dropcloths, and shall isolate the operation using mini-enclosures or glove bag systems pursuant to paragraph (g)(5) of this section.

(iv) Where the employer does not produce a "negative exposure assessment" for a job, or where monitoring results show the PEL has been exceeded, the employer shall contain the area using impermeable dropcloths and plastic barriers or their equivalent, or shall isolate the operation using a control system listed in and in compliance with paragraph (g)(5) of this section.

(v) Employees performing Class III jobs, which involve the disturbance of thermal system insulation or surfacing material, or where the employer does not produce a "negative exposure assessment" or where monitoring results show a PEL has been exceeded, shall wear respirators which are selected, used and fitted pursuant to provisions of paragraph (h) of this section.

(10) Class IV asbestos work. Class IV asbestos jobs shall be conducted by employees trained pursuant to the asbestos awareness training program set out in paragraph (k)(8) of this section. In addition, all Class IV jobs shall be conducted in conformity with the requirements set out in paragraph (g)(1) of this section, mandating wet methods, HEPA vacuums, and prompt clean up of debris containing ACM or PACM.

(i) Employees cleaning up debris and waste in a regulated area where respirators are required shall wear respirators which are selected, used and fitted pursuant to provisions of paragraph (h) of this section.

(ii) Employers of employees who clean up waste and debris in, and employers in control of, areas where friable thermal system insulation or surfacing material is accessible, shall assume that such waste and debris contain asbestos.

(h) Respiratory protection -- (1) General. The employer shall provide respirators, and ensure that they are used, where required by this section. Respirators shall be used in the following circumstances:

(i) During all Class I asbestos jobs.

(ii) During all Class II work where the ACM is not removed in a substantially intact state,

(iii) During all Class II and III work which is not performed using wet methods.

(iv) During all Class II and III asbestos jobs where the employer does not produce a "negative exposure assessment".

(v) During all Class III jobs where TSI or surfacing ACM or PACM is being disturbed.

(vi) During all Class IV work performed within regulated areas where employees performing other work are required to wear respirators.

(vii) During all work covered by this section where employees are exposed above the TWA or excursion limit.

(viii) In emergencies.

(2) Respirator selection. (i) Where respirators are used, the employer shall select and provide, at no cost to the employee, the appropriate respirator as specified in Table 1 in paragraph (h)(2)(iii) of this section, and shall ensure that the employee uses the respirator provided.

(ii) The employer shall select respirators from among those jointly approved as being acceptable for protection by the Mine Safety and Health Administration (MSHA) and the National Institute for Occupational Safety and Health (NIOSH) under the provisions of 30 CFR Part 11.

(iii) The employer shall provide a tight fitting powered, air-purifying respirator in lieu of any negative-pressure respirator specified in Table 1 whenever:

(A) An employee chooses to use this type of respirator; and

(B) This respirator will provide adequate protection to the employee.

Table 1. -- Respiratory Protection for Asbestos Fibers
Airborne concentration of asbestos or conditions of use Required respirator
Not in excess of 1 f/cc (10 X PEL), or otherwise as required independent of exposure pursuant to (h)(2)(iv) Half-mask air purifying respirator other than a disposable respirator, equipped with high efficiency filters
Not in excess of 5 f/cc (50 X PEL) Full facepiece air-purifying respirator equipped with high efficiency filters
Not in excess of 10 f/cc (100 X PEL) Any powered air-purifying respirator equipped with high efficiency filters or any supplied air respirator operated in continuous flow mode
Not in excess of 100 f/cc (1,000 X PEL) Full facepiece supplied air respirator operated in pressure demand mode
Greater than 100 f/cc (1,000 X PEL) or unknown concentration Full facepiece supplied air respirator operated in pressure demand mode, equipped with an auxiliary positive pressure self-contained breathing apparatus
Note:a. Respirators assigned for high environmental concentrations may be used at lower concentrations, or when required respirator use is independent of concentration
b. A high efficiency filter means a filter that is at least 99.97 percent efficient against mono-dispersed particles of 0.3 micrometers in diameter or larger

(iv) In addition to the above selection criterion, the employer shall provide a half-mask air purifying respirator, other than a disposable respirator, equipped with high efficiency filters whenever the employee performs the following activities: Class II and III asbestos jobs where the employer does not produce a negative exposure assessment; and Class III jobs where TSI or surfacing ACM or PACM is being disturbed.

(v) In addition to the above selection criteria, the employer shall provide a full facepiece supplied air respirator operated in the pressure demand mode equipped with an auxiliary positive pressure self- contained breathing apparatus for all employees within the regulated area where Class I work is being performed for which a negative exposure assessment has not been produced.

(3) Respirator program. (i) Where respiratory protection is used, the employer shall institute a respirator program in accordance with 29 CFR 1910.134(b), (d), (e), and (f).

(ii) The employer shall permit each employee who uses a filter respirator to change the filter elements whenever an increase in breathing resistance is detected and shall maintain an adequate supply of filter elements for this purpose.

(iii) Employees who wear respirators shall be permitted to leave work areas to wash their faces and respirator facepieces whenever necessary to prevent skin irritation associated with respirator use.

(iv) No employee shall be assigned to tasks requiring the use of respirators if, based on his or her most recent examination, an examining physician determines that the employee will be unable to function normally wearing a respirator, or that the safety or health of the employee or of other employees will be impaired by the use of a respirator. Such employee shall be assigned to another job or given the opportunity to transfer to a different position the duties of which he or she is able to perform with the same employer, in the same geographical area, and with the same seniority, status, and rate of pay and other job benefits he or she had just prior to such transfer, if such a different position is available.

(4) Respirator fit testing. (i) The employer shall ensure that the respirator issued to the employee exhibits the least possible facepiece leakage and that the respirator is fitted properly.

(ii) Employers shall perform either quantitative or qualitative face fit tests at the time of initial fitting and at least every 6 months thereafter for each employee wearing a negative-pressure respirator. The qualitative fit tests may be used only for testing the fit of half-mask respirators where they are permitted to be worn, or of full-facepiece air purifying respirators where they are worn at levels at which half-facepiece air purifying respirators are permitted. Qualitative and quantitative fit tests shall be conducted in accordance with Appendix C. The tests shall be used to select facepieces that provide the required protection as prescribed in Table 1 in paragraph (h)(2)(iii) of this section.

(i) Protective clothing -- (1) General. The employer shall provide and require the use of protective clothing, such as coveralls or similar whole-body clothing, head coverings, gloves, and foot coverings for any employee exposed to airborne concentrations of asbestos that exceed the TWA and/or excursion limit prescribed in paragraph (c) of this section, or for which a required negative exposure assessment is not produced, and for any employee performing Class I operations which involve the removal of over 25 linear or 10 square feet of TSI or surfacing ACM and PACM.

(2) Laundering. (i) The employer shall ensure that laundering of contaminated clothing is done so as to prevent the release of airborne asbestos in excess of the TWA or excursion limit prescribed in paragraph (c) of this section.

(ii) Any employer who gives contaminated clothing to another person for laundering shall inform such person of the requirement in paragraph (i)(2)(i) of this section to effectively prevent the release of airborne asbestos in excess of the TWA and excursion limit prescribed in paragraph (c) of this section.

(3) Contaminated clothing. Contaminated clothing shall be transported in sealed impermeable bags, or other closed, impermeable containers, and be labeled in accordance with paragraph (k) of this section.

(4) Inspection of protective clothing. (i) The competent person shall examine worksuits worn by employees at least once per workshift for rips or tears that may occur during performance of work.

(ii) When rips or tears are detected while an employee is working, rips and tears shall be immediately mended, or the worksuit shall be immediately replaced.

(j) Hygiene facilities and practices for employees. (1) Requirements for employees performing Class I asbestos jobs involving over 25 linear or 10 square feet of Tsi or surfacing ACM and PACM.

(i) Decontamination areas: the employer shall establish a decontamination area that is adjacent and connected to the regulated area for the decontamination of such employees. The decontamination area shall consist of an equipment room, shower area, and clean room in series. The employer shall ensure that employees enter and exit the regulated area through the decontamination area.

(A) Equipment room. The equipment room shall be supplied with impermeable, labeled bags and containers for the containment and disposal of contaminated protective equipment.

(B) Shower area. Shower facilities shall be provided which comply with 29 CFR 1910.141(d)(3), unless the employer can demonstrate that they are not feasible. The showers shall be adjacent both to the equipment room and the clean room, unless the employer can demonstrate that this location is not feasible.

Where the employer can demonstrate that it is not feasible to locate the shower between the equipment room and the clean room, or where the work is performed outdoors, the employers shall ensure that employees:

(1) Remove asbestos contamination from their worksuits in the equipment room using a HEPA vacuum before proceeding to a shower that is not adjacent to the work area; or (2) Remove their contaminated worksuits in the equipment room, then don clean worksuits, and proceed to a shower that is not adjacent to the work area.

(C) Clean change room. The clean room shall be equipped with a locker or appropriate storage container for each employee's use. When the employer can demonstrate that it is not feasible to provide a clean change area adjacent to the work area or where the work is performed outdoors, the employer may permit employees engaged in Class I asbestos jobs to clean their protective clothing with a portable HEPA-equipped vacuum before such employees leave the regulated area. Such employees however must then change into street clothing in clean change areas provided by the employer which otherwise meet the requirements of this section.

(ii) Decontamination area entry procedures. The employer shall ensure that employees:

(A) Enter the decontamination area through the clean room;

(B) Remove and deposit street clothing within a locker provided for their use; and

(C) Put on protective clothing and respiratory protection before leaving the clean room.

(D) Before entering the regulated area, the employer shall ensure that employees pass through the equipment room.

(iii) Decontamination area exit procedures. The employer shall ensure that:

(A) Before leaving the regulated area, employees shall remove all gross contamination and debris from their protective clothing.

(B) Employees shall remove their protective clothing in the equipment room and deposit the clothing in labeled impermeable bags or containers.

(C) Employees shall not remove their respirators in the equipment room.

(D) Employees shall shower prior to entering the clean room.

(E) After showering, employees shall enter the clean room before changing into street clothes.

(iv) Lunch Areas. Whenever food or beverages are consumed at the worksite where employees are performing Class I asbestos work, the employer shall provide lunch areas in which the airborne concentrations of asbestos are below the permissible exposure limit and/or excursion limit.

(2) Requirements for Class I work involving less than 25 linear or 10 square feet of TSI or surfacing ACM and PACM, and for Class II and Class III asbestos work operations where exposures exceed a PEL or where there is no negative exposure assessment produced before the operation.

(i) The employer shall establish an equipment room or area that is adjacent to the regulated area for the decontamination of employees and their equipment which is contaminated with asbestos which shall consist of an area covered by a impermeable drop cloth on the floor or horizontal working surface.

(ii) The area must be of sufficient size as to accommodate cleaning of equipment and removing personal protective equipment without spreading contamination beyond the area (as determined by visible accumulations).

(iii) Workclothing must be cleaned with a HEPA vacuum before it is removed.

(iv) All equipment and surfaces of containers filled with ACM must be cleaned prior to removing them from the equipment room or area.

(v) The employer shall ensure that employees enter and exit the regulated area through the equipment room or area.

(3) Requirements for Class IV work. Employers shall ensure that employees performing Class IV work within a regulated area comply with the hygiene practice required of employees performing work which has a higher classification within that regulated area. Otherwise employers of employees cleaning up debris and material which is TSI or surfacing ACM or identified as PACM shall provide decontamination facilities for such employees which are required by paragraph (j)(2) of this section.

(4) Smoking in work areas. The employer shall ensure that employees do not smoke in work areas where they are occupationally exposed to asbestos because of activities in that work area.

(k) Communication of hazards. NOTE: This section applies to the communication of information concerning asbestos hazards in construction activities to facilitate compliance with this standard. Most asbestos-related construction activities involve previously installed building materials. Building owners often are the only and/or best sources of information concerning them. Therefore, they, along with employers of potentially exposed employees, are assigned specific information conveying and retention duties under this section. Installed Asbestos Containing Building Material. Employers and building owners are required to treat TSI and sprayed or troweled on surfacing materials in buildings as asbestos-containing, unless they determine in compliance with paragraph (k)(4) of this section that the material is not asbestos-containing. Asphalt and vinyl flooring material installed no later than 1980 must also be considered as asbestos containing unless the employer, pursuant to paragraph (g) of this section determines that it is not asbestos-containing. If the employer/building owner has actual knowledge, or should have known through the exercise of due diligence, that other materials are asbestos-containing, they too must be treated as such. When communicating information to employees pursuant to this standard, owners and employers shall identify "PACM" as ACM. Additional requirements relating to communication of asbestos work on multi-employer worksites are set out in paragraph (d) of this section.

(1) Duties of building and facility owners. (i) Before work subject to this standard is begun, building and facility owners shall identify the presence, location and quantity of ACM, and/or PACM at the work site. All thermal system insulation and sprayed on or troweled on surfacing m2aterials in buildings or substrates constructed no later than 1980 shall also be identified as asbestos-containing. In addition resilient flooring material installed not later than 1980 shall also be identified as asbestos-containing.

(ii) Building and/or facility owners shall notify the following persons of the presence, location and quantity of ACM or PACM, at the work sites in their buildings and facilities. Notification either shall be in writing, or shall consist of a personal communication between the owner and the person to whom notification must be given or their authorized representatives:

(A) Prospective employers applying or bidding for work whose employees reasonably can be expected to work in or adjacent to areas containing such material;

(B) Employees of the owner who will work in or adjacent to areas containing such material:

(C) On multi-employer worksites, all employers of employees who will be performing work within or adjacent to areas containing such materials;

(D) Tenants who will occupy areas containing such material.

(2) Duties of employers whose employees perform work subject to this standard in or adjacent to areas containing ACM and PACM. Building/facility owners whose employees perform such work shall comply with these provisions to the extent applicable.

(i) Before work in areas containing ACM and PACM is begun; employers shall identify the presence, location, and quantity of ACM, and/or PACM therein.

(ii) Before work under this standard is performed employers of employees who will perform such work shall inform the following persons of the location and quantity of ACM and/or PACM present in the area and the precautions to be taken to insure that airborne asbestos is confined to the area.

(A) Owners of the building/facility;

(B) Employees who will perform such work and employers of employees who work and/or will be working in adjacent areas.

(iii) Within 10 days of the completion of such work, the employer whose employees have performed work subject to this standard, shall inform the building/facility owner and employers of employees who will be working in the area of the current location and quantity of PACM and/or ACM remaining in the area and final monitoring results, if any.

(3) In addition to the above requirements, all employers who discover ACM and/or PACM on a worksite shall convey information concerning the presence, location and quantity of such newly discovered ACM and/or PACM to the owner and to other employers of employees working at the work site, within 24 hours of the discovery.

(4) Criteria to rebut the designation of installed material as PACM. (i) At any time, an employer and/or building owner may demonstrate, for purposes of this standard, that PACM does not contain asbestos. Building owners and/or employers are not required to communicate information about the presence of building material for which such a demonstration pursuant to the requirements of paragraph (k)(4)(ii) of this section has been made. However, in all such cases, the information, data and analysis supporting the determination that PACM does not contain asbestos, shall be retained pursuant to paragraph (n) of this section.

(ii) An employer or owner may demonstrate that PACM does not contain asbestos by the following: (A) Having an completed inspection conducted pursuant to the requirements of AHERA (40 CFR Part 763, Subpart E) which demonstrates that the material is not ACM;

(B) Performing tests of the material containing PACM which demonstrate that no asbestos is present in the material. Such tests shall include analysis of 3 bulk samples of each homogeneous area of PACM collected in a randomly distributed manner. The tests, evaluation and sample collection shall be conducted by an accredited inspector or by a CIH. Analysis of samples shall be performed by persons or laboratories with proficiency demonstrated by current successful participation in a nationally recognized testing program such as the National Voluntary Laboratory Accreditation Program (NVLAP) of the National Institute for Standards and Technology (NIST) of the Round Robin for bulk samples administered by the American Industrial Hygiene Association (AIHA) or an equivalent nationally-recognized round robin testing program.

(5) At the entrance to mechanical rooms/areas in which employees reasonably can be expected to enter and which contain thermal system insulation and surfacing ACM/PACM, the building owner shall post signs which identify the material which is present, its location, and appropriate work practices which, if followed, will ensure that ACM and/or PACM will not be disturbed.

(6) Signs. (i) Warning signs that demarcate the regulated area shall be provided and displayed at each location where a regulated area is required to be established by paragraph (e) of this section. Signs shall be posted at such a distance from such a location that an employee may read the signs and take necessary protective steps before entering the area marked by the signs.

(ii) The warning signs required by (k)(6) of this section shall bear the following information.

DANGER
ASBESTOS
CANCER AND LUNG DISEASE HAZARD
AUTHORIZED PERSONNEL ONLY
RESPIRATORS AND PROTECTION CLOTHING ARE REQUIRED IN THIS AREA

(7) Labels. (i) Labels shall be affixed to all products containing asbestos and to all containers containing such products, including waste containers. Where feasible, installed asbestos products shall contain a visible label.

(ii) Labels shall be printed in large, bold letters on a contrasting background.

(iii) Labels shall be used in accordance with the requirements of 29 CFR 1910.1200(f) of OSHA's Hazard Communication standard, and shall contain the following information:

DANGER
CONTAINS ASBESTOS FIBERS
AVOID CREATING DUST
CANCER AND LUNG DISEASE HAZARD

(iv) [Reserved]

(v) Labels shall contain a warning statement against breathing asbestos fibers.

(vi) The provisions for labels required by paragraphs (k)(2)(i) through (k)(2)(iii) do not apply where:

(A) Asbestos fibers have been modified by a bonding agent, coating, binder, or other material, provided that the manufacturer can demonstrate that, during any reasonably foreseeable use, handling, storage, disposal, processing, or transportation, no airborne concentrations of asbestos fibers in excess of the permissible exposure limit and/or excursion limit will be released, or (B) Asbestos is present in a product in concentrations less than 1.0 percent by weight.

(vii) When a building owner/or employer identifies previously installed PACM and/or ACM, labels or signs shall be affixed or posted so that employees will be notified of what materials contain PACM and/ or ACM. The employer shall attach such labels in areas where they will clearly be noticed by employees who are likely to be exposed, such as at the entrance to mechanical room/areas. Signs required by paragraph (k)(5) of this section may be posted in lieu of labels so long as they contain information required for labelling.

(8) Employee information and training. (i) The employer shall, at no cost to the employee, institute a training program for all employees who install asbestos containing products and for all employees who perform Class I through IV asbestos operations, and shall ensure their participation in the program.

(ii) Training shall be provided prior to or at the time of initial assignment and at least annually thereafter.

(iii) Training for Class I and II operations shall be the equivalent in curriculum, training method and length to the EPA Model Accreditation Plan (MAP) asbestos abatement worker training (40 CFR Part 763, Subpart E, Appendix C.). For employers whose Class II work with asbestos-containing material involves only the removal and/or disturbance of one generic category of building material, such as roofing materials, flooring materials, siding materials or transite panels, instead, such employer is required to train employees who perform such work by providing a training course which includes as a minimum all the elements included in paragraph (k)(8)(vi) of this section and in addition, the specific work practices and engineering controls set forth in paragraph (g) which specifically relate to that category. Such course shall include "hands-on" training and shall take at least 8 hours.

(iv) Training for Class III employees shall be the equivalent in curriculum and training method to the 16-hour Operations and Maintenance course developed by EPA for maintenance and custodial workers who conduct activities that will result in the disturbance of ACM. [See 40 CFR 763.92(a)(2)]. Such course shall include "hands-on" training in the use of respiratory protection and work practices and shall take at least 16 hours.

(v) Training for employees performing Class IV operations shall be the equivalent in curriculum and training method to the awareness training course developed by EPA for maintenance and custodial workers who work in buildings containing asbestos- containing material. [See 40 CFR 763.92 (a)(1)]. Such course shall include available information concerning the locations of PACM and ACM, and asbestos-containing flooring material, or flooring material where the absence of asbestos has not been certified; and instruction in recognition of damage, deterioration, and delamination of asbestos containing building materials. Such a course shall take at least 2 hours.

(vi) The training program shall be conducted in a manner that the employee is able to understand. In addition to the content required by provisions in paragraph (k)(8)(iii) of this section, the employer shall ensure that each such employee is informed of the following:

(A) Methods of recognizing asbestos, including the requirement in paragraph (k)(1) of this section to presume that certain building materials contain asbestos;

(B) The health effects associated with asbestos exposure;

(C) The relationship between smoking and asbestos in producing lung cancer;

(D) The nature of operations that could result in exposure to asbestos, the importance of necessary protective controls to minimize exposure including, as applicable, engineering controls, work practices, respirators, housekeeping procedures, hygiene facilities, protective clothing, decontamination procedures, emergency procedures, and waste disposal procedures, and any necessary instruction in the use of these controls and procedures; including where Class III and IV work is performed, the contents of "Managing Asbestos In Place (EPA 20T-2003, July 1990) or its equivalent in content.

(E) The purpose, proper use, fitting instructions, and limitations of respirators as required by 29 CFR 1910.134;

(F) The appropriate work practices for performing the asbestos job;

(G) Medical surveillance program requirements; and

(H) The content of this standard, including appendices.

(I) The names, addresses and phone numbers of public health organizations which provide information, materials and/or conduct programs concerning smoking cessation. The employer may distribute the list of such organizations contained in Appendix J to this section, to comply with this requirement.

(J) The requirements for posting signs and affixing labels and the meaning of the required legends for such signs and labels.

(9) Access to training materials. (i) The employer shall make readily available to affected employees without cost, written materials relating to the employee training program, including a copy of this regulation.

(ii) The employer shall provide to the Assistant Secretary and the Director, upon request, all information and training materials relating to the employee information and training program.

(iii) The employer shall inform all employees concerning the availability of self-help smoking cessation program material. Upon employee request, the employer shall distribute such material, consisting of NIH Publication No, 89-1647, or equivalent self-help material, which is approved or published by a public health organization listed in Appendix J to this section.

(l) Housekeeping -- (1) Vacuuming. Where vacuuming methods are selected, HEPA filtered vacuuming equipment must be used. The equipment shall be used and emptied in a manner that minimizes the reentry of asbestos into the workplace.

(2) Waste disposal. Asbestos waste, scrap, debris, bags, containers, equipment, and contaminated clothing consigned for disposal shall be collected and disposed of in sealed, labeled, impermeable bags or other closed, labeled, impermeable containers.

(3) Care of asbestos-containing flooring material. (i) All vinyl and asphalt flooring material shall be maintained in accordance with this paragraph unless the building/facility owner demonstrates, pursuant to paragraph (g) of this section that the flooring does not contain asbestos.

(i) Sanding of flooring material is prohibited.

(ii) Stripping of finishes shall be conducted using low abrasion pads at speed lower than 300 rpm and wet methods.

(iii) Burnishing or dry buffing may be performed only on flooring which has sufficient finish so that the pad cannot contact the flooring material.

(4) Dust and debris in an area containing accessible thermal system insulation or surfacing material or visibly deteriorated ACM:

(i) shall not be dusted or swept dry, or vacuumed without using a HEPA filter;

(ii) shall be promptly clean up and disposed in leak tight containers.

(m) Medical surveillance -- (1) General -- (i) Employees covered. The employer shall institute a medical surveillance program for all employees who for a combined total of 30 or more days per year are engaged in Class I, II and III work or are exposed at or above the permissible exposure limit or excursion limit, and for employees who wear negative pressure respirators pursuant to the requirements of this section.

(ii) Examination by a physician.

(A) The employer shall ensure that all medical examinations and procedures are performed by or under the supervision of a licensed physician, and are provided at no cost to the employee and at a reasonable time and place.

(B) Persons other than such licensed physicians who administer the pulmonary function testing required by this section shall complete a training course in spirometry sponsored by an appropriate academic or professional institution.

(2) Medical examinations and consultations-(i) Frequency. The employer shall make available medical examinations and consultations to each employee covered under paragraph (m)(1)(i) of this section on the following schedules:

(A) Prior to assignment of the employee to an area where negative- pressure respirators are worn;

(B) When the employee is assigned to an area where exposure to asbestos may be at or above the permissible exposure for 30 or more days per year, a medical examination must be given within 10 working days following the thirtieth day of exposure;

(C) And at least annually thereafter. (D) If the examining physician determines that any of the examinations should be provided more frequently than specified, the employer shall provide such examinations to affected employees at the frequencies specified by the physician.

(E) Exception: No medical examination is required of any employee if adequate records show that the employee has been examined in accordance with this paragraph within the past 1-year period.

(ii) Content. Medical examinations made available pursuant to paragraphs (m)(2)(i)(A) through (m)(2)(i)(C) of this section shall include:

(A) A medical and work history with special emphasis directed to the pulmonary, cardiovascular, and gastrointestinal systems.

(B) On initial examination, the standardized questionnaire contained in Part 1 of Appendix D to this section, and, on annual examination, the abbreviated standardized questionnaire contained in Part 2 of Appendix D to this section.

(C) A physical examination directed to the pulmonary and gastrointestinal systems, including a chest roentgenogram to be administered at the discretion of the physician, and pulmonary function tests of forced vital capacity (FVC) and forced expiratory volume at one second (FEV(1)). Interpretation and classification of chest shall be conducted in accordance with Appendix E to this section.

(D) Any other examinations or tests deemed necessary by the examining physician.

(3) Information provided to the physician. The employer shall provide the following information to the examining physician:

(i) A copy of this standard and Appendices D, E, G, and I to this section;

(ii) A description of the affected employee's duties as they relate to the employee's exposure;

(iii) The employee's representative exposure level or anticipated exposure level;

(iv) A description of any personal protective and respiratory equipment used or to be used; and

(v) Information from previous medical examinations of the affected employee that is not otherwise available to the examining physician.

(4) Physician's written opinion. (i) The employer shall obtain a written opinion from the examining physician. This written opinion shall contain the results of the medical examination and shall include:

(A) The physician's opinion as to whether the employee has any detected medical conditions that would place the employee at an increased risk of material health impairment from exposure to asbestos;

(B) Any recommended limitations on the employee or on the use of personal protective equipment such as respirators; and

(C) A statement that the employee has been informed by the physician of the results of the medical examination and of any medical conditions that may result from asbestos exposure.

(D) A statement that the employee has been informed by the physician of the increased risk of lung cancer attributable to the combined effect of smoking and asbestos exposure.

(ii) The employer shall instruct the physician not to reveal in the written opinion given to the employer specific findings or diagnoses unrelated to occupational exposure to asbestos.

(iii) The employer shall provide a copy of the physician's written opinion to the affected employee within 30 days from its receipt.

(n) Recordkeeping -- (1) Objective data relied on pursuant to paragraph (f) to this section. (i) Where the employer has relied on objective data that demonstrate that products made from or containing asbestos are not capable of releasing fibers of asbestos in concentrations at or above the permissible exposure limit and/or excursion limit under the expected conditions of processing, use, or handling to satisfy the requirements of paragraph (f), the employer shall establish and maintain an accurate record of objective data reasonably relied upon in support of the exemption.

(ii) The record shall include at least the following information:

(A) The product qualifying for exemption;

(B) The source of the objective data;

(C) The testing protocol, results of testing, and/or analysis of the material for the release of asbestos;

(D) A description of the operation exempted and how the data support the exemption; and

(E) Other data relevant to the operations, materials, processing, or employee exposures covered by the exemption.

(iii) The employer shall maintain this record for the duration of the employer's reliance upon such objective data.

(2) Exposure measurements. (i) The employer shall keep an accurate record of all measurements taken to monitor employee exposure to asbestos as prescribed in paragraph (f) of this section. NOTE: The employer may utilize the services of competent organizations such as industry trade associations and employee associations to maintain the records required by this section.

(ii) This record shall include at least the following information:

 

(A) The date of measurement;

(B) The operation involving exposure to asbestos that is being monitored;

(C) Sampling and analytical methods used and evidence of their accuracy;

(D) Number, duration, and results of samples taken;

(E) Type of protective devices worn, if any; and

(F) Name, social security number, and exposure of the employees whose exposures are represented.

(iii) The employer shall maintain this record for at least thirty (30) years, in accordance with 29 CFR 1910.20.

(3) Medical surveillance. (i) The employer shall establish and maintain an accurate record for each employee subject to medical surveillance by paragraph (m) of this section, in accordance with 29 CFR 1910.20.

(ii) The record shall include at least the following information:

(A) The name and social security number of the employee;

(B) A copy of the employee's medical examination results, including the medical history, questionnaire responses, results of any tests, and physician's recommendations.

(C) Physician's written opinions;

(D) Any employee medical complaints related to exposure to asbestos; and

(E) A copy of the information provided to the physician as required by paragraph (m) of this section.

(iii) The employer shall ensure that this record is maintained for the duration of employment plus thirty (30) years, in accordance with 29 CFR 1910.20.

(4) Training records. The employer shall maintain all employee training records for one 1 year beyond the last date of employment by that employer.

(5) Data to Rebut PACM. Where the building owner and employer have relied on data to demonstrate that PACM is not asbestos-containing, such data shall be maintained far as long as they are relied upon to rebut the presumption.

(6) Records of Required Notifications. Where the building owner has communicated and received information concerning the identification, location and quantity of ACM and PACM, written records of such notifications and their content shall be maintained by the building owner for the duration of ownership and shall be transferred to successive owners of such buildings/facilities.

(7) Availability. (i) The employer, upon written request, shall make all records required to be maintained by this section available to the Assistant Secretary and the Director for examination and copying.

(ii) The employer, upon request, shall make any exposure records required by paragraphs (f) and (n) of this section available for examination and copying to affected employees, former employees, designated representatives, and the Assistant Secretary, in accordance with 29 CFR 1910.20(a) through (e) and (g) through (i).

(iii) The employer, upon request, shall make employee medical records required by paragraphs (m) and (n) of this section available for examination and copying to the subject employee, anyone having the specific written consent of the subject employee, and the Assistant Secretary, in accordance with 29 CFR 1910.20.

(8) Transfer of records. (i) The employer shall comply with the requirements concerning transfer of records set forth in 29 CFR 1910.20 (h).

(ii) Whenever the employer ceases to do business and there is no successor employer to receive and retain the records for the prescribed period, the employer shall notify the Director at least 90 days prior to disposal and, upon request, transmit them to the Director.

(o) Competent person -- (1) General. On all construction worksites covered by this standard, the employer shall designate a competent person, having the qualifications and authorities for ensuring worker safety and health required by Subpart C, General Safety and Health Provisions for Construction (29 CFR 1926.20 through 1926.32).

(2) Required Inspections by the Competent Person. Section 1926.20(b)(2) which requires health and safety prevention programs to provide for frequent and regular inspections of the job sites, materials, and equipment to be made by competent persons, is incorporated.

(3) Additional Inspections. In addition, the competent person shall make frequent and regular inspections of the job sites, in order to perform the duties set out below in paragraph (p)(3)(i) and (ii) of this section. For Class I jobs, on-site inspections shall be made at least once during each work shift, and at any time at employee request. For Class II and III jobs, on-site inspections shall be made at intervals sufficient to assess whether conditions have changed, and at any reasonable time at employee request.

(i) On all worksites where employees are engaged in Class I or II asbestos work, the competent person designated in accordance with paragraph (g)(1) of this section shall perform or supervise the following duties, as applicable:

(A) Set up the regulated area, enclosure, or other containment;

(B) Ensure (by on-site inspection) the integrity of the enclosure or containment;

(C) Set up procedures to control entry to and exit from the enclosure and/or area;

(D) Supervise all employee exposure monitoring required by this section and ensure that it is conducted as required by paragraph (f) of this section;

(E) Ensure that employees working within the enclosure and/or using glove bags wear protective clothing and respirators as required by paragraphs (h) and (i) of this section;

(F) Ensure through on-site supervision, that employees set up and remove engineering controls, use work practices and personal protective equipment in compliance with all requirements;

(G) Ensure that employees use the hygiene facilities and observe the decontamination procedures specified in paragraph (j) of this section;

(H) Ensure that though on-site inspection engineering controls are functioning properly and employees are using proper work practices; and,

(I) Ensure that notification requirement in paragraph (f)(6) of this section are met.

(4) Training for the competent person. (i) For Class I, and II asbestos work the competent person shall be trained in all aspects of asbestos removal and handling, including: abatement, installation, removal and handling; the contents of this standard; the identification of asbestos; removal procedures, where appropriate; and other practices for reducing the hazard. Such training shall be obtained in a comprehensive course for supervisors, such as a course conducted by an EPA or state-approved training provider, certified by the EPA or a State, or an course equivalent in stringency, content and length.

(ii) For Class III and IV asbestos work, the competent person shall be trained in aspects of asbestos handling appropriate for the nature of the work, to include procedures for setting up glove bags and mini- enclosures, practices for reducing asbestos exposures, use of wet methods, the contents of this standard, and the identification of asbestos. Such training shall include successful completion of a course equivalent in curriculum and training method to the 16-hour Operations and Maintenance course developed by EPA for maintenance and custodial workers [See 40 CFR 763.92(a)(2)], or its equivalent in stringency, content and length. Competent persons for Class III and IV work, may also be trained pursuant to the requirements of paragraph (o)(4)(i) of this section.

(p) Appendices. (1) Appendices A, C, D, and E to this section are incorporated as part of this section and the contents of these appendices are mandatory.

(2) Appendices B, F, H, I, J, and K to this section are informational and are not intended to create any additional obligations not otherwise imposed or to detract from any existing obligations.

(q) Dates. (1) This standard shall become effective October 11, 1994.

(2) The provisions of 29 CFR 1926.58 remain in effect until the start-up dates of the equivalent provisions of this standard.

(3) Start-up dates: All obligations of this standard commence on the effective date except as follows:

(i) Methods of compliance. The engineering and work practice controls required by paragraph (g) of this section shall be implemented as soon as possible but no later than April 10, 1995.

(ii) Respiratory protection. Respiratory protection required by paragraph (h) of this section shall be provided as soon as possible but no later than February 8, 1995.

(iii) Hygiene facilities and practices for employees. Hygiene facilities and practices required by paragraph (j) of this section shall be provided as soon as possible but no later than February 8, 1995.

(iv) Communication of hazards. Identification, notification, labeling and sign posting, and training required by paragraph (k) of this section shall be provided as soon as possible, but no later than April 10, 1995.

(v) Housekeeping. Housekeeping practices and controls required by paragraph (l) of this section shall be provided as soon as possible, but no later than January 9, 1995.

(vi) Medical surveillance required by paragraph (m) of this section shall be provided as soon as possible, but no later than January 9, 1995.

(vii) The designation and training of competent persons required by paragraph (o) of this section shall completed as soon as possible but no later than April 10, 1995.

(Approved by the Office of Management and Budget under control number 1218-0133)

Appendix A to 1926.1101 [Amended]

4. Appendix A to Sec. 1926.1101 is amended by the revising the second sentence of the introductory paragraph to read as follows:

* * * The sampling and analytical methods described below represent the elements of the available monitoring methods (such as Appendix B of this regulation, the most current version of the OSHA method ID-160, or the most current version of the NIOSH Method 7400). * * *

Appendix A to 1926.1101 [Amended]

5. Paragraph 2. of the section of Appendix A to Sec. 1926.1101 entitled Sampling and Analytical Procedure is amended by adding the following sentence to the end:

* * * * *

2.* * * Do not reuse or reload cassettes for asbestos sample collection. * * * * *

Appendix A to 1926.1101 [Amended]

6. Paragraph 11 of the section of Appendix A to Sec. 1926.1101 entitled Sampling and Analytical Procedure is revised to read as follows:

* * * * *

11. Each set of samples taken will include 10% field blanks or a minimum of 2 field blanks. These blanks must come from the same lot as the filters used for sample collection. The field blank results shall be averaged and subtracted from the analytical results before reporting. A set consists of any sample or group of samples for which an evaluation for this standard must be made. Any samples represented by a field blank having a fiber count in excess of the detection limit of the method being used shall be rejected.

* * * * *

Appendix A to 1926.1101 [Amended]

7. Paragraph 2 of the section of Appendix A to Sec. 1926.1101 entitled Quality Control Procedures is redesignated as paragraph 2a and by adding paragraph 2b to read as follows:

* * * * *

2. * * * b. All laboratories should also participate in a national sample testing scheme such as the Proficiency Analytical Testing Program (PAT), or the Asbestos Registry sponsored by the American Industrial Hygiene Association (AIHA).

* * * * *

E. Appendix B of Sec. 1926.1101 is revised to read as follows:

Appendix B to 1926.1101. Sampling and Analysis. Non-mandatory

Air
Matrix:
  • OSHA Permissible Exposure Limits:
  • Time Weighted Average
0.1 fiber/cc
  • Excursion Level (30 minutes)
1.0 fiber/cc
Collection Procedure:
  • A known volume of air is drawn through a 25-mm diameter cassette containing a mixed-cellulose ester filter. The cassette must be equipped with an electrically conductive 50-mm extension cowl. The sampling time and rate are chosen to give a fiber density of between 100 to 1,300 fibers/mm2 on the filter
Recommended Sampling Rate 0.5 to 5.0 liters/minute (L/min)
Recommended Air Volumes:
  • Minimum
25 L
  • Maximum
2,400 L

Analytical Procedure:

A portion of the sample filter is cleared and prepared for asbestos fiber counting by Phase Contrast Microscopy (PCM) at 400X.

Commercial manufacturers and products mentioned in this method are for descriptive use only and do not constitute endorsements by USDOL-OSHA. Similar products from other sources can be substituted.

1. Introduction

This method describes the collection of airborne asbestos fibers using calibrated sampling pumps with mixed-cellulose ester (MCE) filters and analysis by phase contrast microscopy (PCM). Some terms used are unique to this method and are defined below: Asbestos: A term for naturally occurring fibrous minerals. Asbestos includes chrysotile, crocidolite, amosite (cummingtonite-grunerite asbestos), tremolite asbestos, actinolite asbestos, anthophyllite asbestos, and any of these minerals that have been chemically treated and/or altered. The precise chemical formulation of each species will vary with the location from which it was mined. Nominal compositions are listed:

Chrysotile.................... Mg(3)Si(2)O(5)(OH)(4)

Crocidolite................... Na(2)Fe(3)(2) + Fe(2)(3) + Si(8)O(2)2(OH)(2)

Amosite....................... (Mg,Fe)(7)Si(8)O(2)2(OH)(2)

Tremolite-actinolite.......... Ca(2)(Mg,Fe)(5)Si(8)O(2)2(OH)(2)

Anthophyllite................. (Mg,Fe)(7)Si(8)O(2)2(OH)(2)

Asbestos Fiber: A fiber of asbestos which meets the criteria specified below for a fiber.

Aspect Ratio: The ratio of the length of a fiber to it's diameter (e.g. 3:1, 5:1 aspect ratios).

Cleavage Fragments: Mineral particles formed by comminution of minerals, especially those characterized by parallel sides and a moderate aspect ratio (usually less than 20:1).

Detection Limit: The number of fibers necessary to be 95% certain that the result is greater than zero.

Differential Counting: The term applied to the practice of excluding certain kinds of fibers from the fiber count because they do not appear to be asbestos.

Fiber: A particle that is 5 um or longer, with a length-to-width ratio of 3 to 1 or longer.

Field: The area within the graticule circle that is superimposed on the microscope image.

Set: The samples which are taken, submitted to the laboratory, analyzed, and for which, interim or final result reports are generated.

Tremolite, Anthophyllite, and Actinolite: The non-asbestos form of these minerals which meet the definition of a fiber. It includes any of these minerals that have been chemically treated and/or altered.

Walton-Beckett Graticule: An eyepiece graticule specifically designed for asbestos fiber counting. It consists of a circle with a projected diameter of 100 plus or minus 2 um (area of about 0.00785 mm(2)) with a crosshair having tic-marks at 3-um intervals in one direction and 5-um in the orthogonal direction. There are marks around the periphery of the circle to demonstrate the proper sizes and shapes of fibers. This design is reproduced in Figure 2. The disk is placed in one of the microscope eyepieces so that the design is superimposed on the field of view.

1.1. History

Early surveys to determine asbestos exposures were conducted using impinger counts of total dust with the counts expressed as million particles per cubic foot. The British Asbestos Research Council recommended filter membrane counting in 1969. In July 1969, the Bureau of Occupational Safety and Health published a filter membrane method for counting asbestos fibers in the United States. This method was refined by NIOSH and published as P&CAM 239. On May 29, 1971, OSHA specified filter membrane sampling with phase contrast counting for evaluation of asbestos exposures at work sites in the United States. The use of this technique was again required by OSHA in 1986. Phase contrast microscopy has continued to be the method of choice for the measurement of occupational exposure to asbestos.

1.2. Principle

Air is drawn through a MCE filter to capture airborne asbestos fibers. A wedge shaped portion of the filter is removed, placed on a glass microscope slide and made transparent. A measured area (field) is viewed by PCM. All the fibers meeting a defined criteria for asbestos are counted and considered a measure of the airborne asbestos concentration.

1.3. Advantages and Disadvantages

There are four main advantages of PCM over other methods:

(1) The technique is specific for fibers. Phase contrast is a fiber counting technique which excludes non-fibrous particles from the analysis.

(2) The technique is inexpensive and does not require specialized knowledge to carry out the analysis for total fiber counts.

(3) The analysis is quick and can be performed on-site for rapid determination of air concentrations of asbestos fibers. (4) The technique has continuity with historical epidemiological estimates of expected disease can be inferred from long-term determinations of asbestos exposures.

The main disadvantage of PCM is that it does not positively identify asbestos fibers. Other fibers which are not asbestos may be included in the count unless differential counting is performed. This requires a great deal of experience to adequately differentiate asbestos from non-asbestos fibers. Positive identification of asbestos must be performed by polarized light or electron microscopy techniques. A further disadvantage of PCM is that the smallest visible fibers are about 0.2 um in diameter while the finest asbestos fibers may be as small as 0.02 um in diameter. For some exposures, substantially more fibers may be present than are actually counted.

1.4. Workplace Exposure

Asbestos is used by the construction industry in such products as shingles, floor tiles, asbestos cement, roofing felts, insulation and acoustical products. Non-construction uses include brakes, clutch facings, paper, paints, plastics, and fabrics. One of the most significant exposures in the workplace is the removal and encapsulation of asbestos in schools, public buildings, and homes. Many workers have the potential to be exposed to asbestos during these operations.

About 95% of the asbestos in commercial use in the United States is chrysotile. Crocidolite and amosite make up most of the remainder. Anthophyllite and tremolite or actinolite are likely to be encountered as contaminants in various industrial products.

1.5. Physical Properties

Asbestos fiber possesses a high tensile strength along its axis, is chemically inert, non-combustible, and heat resistant. It has a high electrical resistance and good sound absorbing properties. It can be weaved into cables, fabrics or other textiles, and also matted into asbestos papers, felts, or mats.

2. Range and Detection Limit

2.1. The ideal counting range on the filter is 100 to 1,300 fibers/mm(2). With a Walton-Beckett graticule this range is equivalent to 0.8 to 10 fibers/field. Using NIOSH counting statistics, a count of 0.8 fibers/field would give an approximate coefficient of variation (CV) of 0.13.

2.2. The detection limit for this method is 4.0 fibers per 100 fields or 5.5 fibers/mm(2). This was determined using an equation to estimate the maximum CV possible at a specific concentration (95% confidence) and a Lower Control Limit of zero. The CV value was then used to determine a corresponding concentration from historical CV vs fiber relationships. As an example:

Lower Control Limit (95% Confidence) = AC -- 1.645(CV)(AC)

Where:

AC = Estimate of the airborne fiber concentration (fibers/cc) Setting the

Lower Control Limit = 0 and solving for CV:

0 = AC - 1.645(CV)(AC) CV = 0.61

This value was compared with CV vs. count curves. The count at which CV = 0.61 for Leidel-Busch counting statistics or for an OSHA Salt Lake Technical Center (OSHA-SLTC) CV curve (see Appendix A for further information) was 4.4 fibers or 3.9 fibers per 100 fields, respectively. Although a lower detection limit of 4 fibers per 100 fields is supported by the OSHA-SLTC data, both data sets support the 4.5 fibers per 100 fields value.

3. Method Performance -- Precision and Accuracy

Precision is dependent upon the total number of fibers counted and the uniformity of the fiber distribution on the filter. A general rule is to count at least 20 and not more than 100 fields. The count is discontinued when 100 fibers are counted, provided that 20 fields have already been counted. Counting more than 100 fibers results in only a small gain in precision. As the total count drops below 10 fibers, an accelerated loss of precision is noted.

At this time, there is no known method to determine the absolute accuracy of the asbestos analysis. Results of samples prepared through the Proficiency Analytical Testing (PAT) Program and analyzed by the OSHA-SLTC showed no significant bias when compared to PAT reference values. The PAT samples were analyzed from 1987 to 1989 (N=36) and the concentration range was from 120 to 1,300 fibers/mm(2).

4. Interferences

Fibrous substances, if present, may interfere with asbestos analysis. Some common fibers are:

fiber glass........................ perlite veins anhydrite plant fibers gypsum............................. some synthetic fibers membrane structures................ sponge spicules and diatoms microorganisms..................... wollastonite

The use of electron microscopy or optical tests such as polarized light, and dispersion staining may be used to differentiate these materials from asbestos when necessary.

5. Sampling

5.1. Equipment

5.1.1. Sample assembly (The assembly is shown in Figure 3). Conductive filter holder consisting of a 25-mm diameter, 3-piece cassette having a 50-mm long electrically conductive extension cowl. Backup pad, 25-mm, cellulose. Membrane filter, mixed-cellulose ester (MCE), 25-mm, plain, white, 0.8- to 1.2-um pore size.

Notes:

(a) DO NOT RE-USE CASSETTES. (b) Fully conductive cassettes are required to reduce fiber loss to the sides of the cassette due to electrostatic attraction.

(c) Purchase filters which have been selected by the manufacturer for asbestos counting or analyze representative filters for fiber background before use. Discard the filter lot if more than 4 fibers/ 100 fields are found.

(d) To decrease the possibility of contamination, the sampling system (filter-backup pad-cassette) for asbestos is usually preassembled by the manufacturer.

5.1.2. Gel bands for sealing cassettes.

5.1.3. Sampling pump. Each pump must be a battery operated, self-contained unit small enough to be placed on the monitored employee and not interfere with the work being performed. The pump must be capable of sampling at 2.5 liters per minute (L/min) for the required sampling time.

5.1.4. Flexible tubing, 6-mm bore.

5.1.5. Pump calibration. Stopwatch and bubble tube/burette or electronic meter.

5.2. Sampling Procedure

5.2.1. Seal the point where the base and cowl of each cassette meet (see Figure 3) with a gel band or tape.

5.2.2. Charge the pumps completely before beginning.

5.2.3. Connect each pump to a calibration cassette with an appropriate length of 6-mm bore plastic tubing. Do not use luer connectors -- the type of cassette specified above has built-in adapters.

5.2.4. Select an appropriate flow rate for the situation being monitored. The sampling flow rate must be between 0.5 and 5.0 L/min for personal sampling and is commonly set between 1 and 2 L/min. Always choose a flow rate that will not produce overloaded filters.

5.2.5. Calibrate each sampling pump before and after sampling with a calibration cassette in-line (Note: This calibration cassette should be from the same lot of cassettes used for sampling). Use a primary standard (e.g. bubble burette) to calibrate each pump. If possible, calibrate at the sampling site.

Note: If sampling site calibration is not possible, environmental influences may affect the flow rate. The extent is dependent on the type of pump used. Consult with the pump manufacturer to determine dependence on environmental influences. If the pump is affected by temperature and pressure changes, use the formula in Appendix B to calculate the actual flow rate.

5.2.6. Connect each pump to the base of each sampling cassette with flexible tubing. Remove the end cap of each cassette and take each air sample open face. Assure that each sample cassette is held open side down in the employee's breathing zone during sampling. The distance from the nose/mouth of the employee to the cassette should be about 10 cm. Secure the cassette on the collar or lapel of the employee using spring clips or other similar devices.

5.2.7. A suggested minimum air volume when sampling to determine TWA compliance is 25 L. For Excursion Limit (30 min sampling time) evaluations, a minimum air volume of 48 L is recommended.

5.2.8. The most significant problem when sampling for asbestos is overloading the filter with non-asbestos dust. Suggested maximum air sample volumes for specific environments are:

Environment Air Vol. (L)
Asbestos removal operations (visible dust) 100
Asbestos removal operations (little dust) 240
Office environments 400 to 2,400

CAUTION: Do not overload the filter with dust. High levels of non-fibrous dust particles may obscure fibers on the filter and lower the count or make counting impossible. If more than about 25 to 30% of the field area is obscured with dust, the result may be biased low. Smaller air volumes may be necessary when there is excessive non-asbestos dust in the air.

While sampling, observe the filter with a small flashlight. If there is a visible layer of dust on the filter, stop sampling, remove and seal the cassette, and replace with a new sampling assembly. The total dust loading should not exceed 1 mg.

5.2.9. Blank samples are used to determine if any contamination has occurred during sample handling. Prepare two blanks for the first 1 to 20 samples. For sets containing greater than 20 samples, prepare blanks as 10% of the samples. Handle blank samples in the same manner as air samples with one exception: Do not draw any air through the blank samples. Open the blank cassette in the place where the sample cassettes are mounted on the employee. Hold it open for about 30 seconds. Close and seal the cassette appropriately. Store blanks for shipment with the sample cassettes.

5.2.10. Immediately after sampling, close and seal each cassette with the base and plastic plugs. Do not touch or puncture the filter membrane as this will invalidate the analysis.

5.2.11. Attach a seal (OSHA-21 or equivalent) around each cassette in such a way as to secure the end cap plug and base plug. Tape the ends of the seal together since the seal is not long enough to be wrapped end-to-end. Also wrap tape around the cassette at each joint to keep the seal secure.

5.3. Sample Shipment

5.3.1. Send the samples to the laboratory with paperwork requesting asbestos analysis. List any known fibrous interferences present during sampling on the paperwork. Also, note the workplace operation(s) sampled.

5.3.2. Secure and handle the samples in such that they will not rattle during shipment nor be exposed to static electricity. Do not ship samples in expanded polystyrene peanuts, vermiculite, paper shreds, or excelsior. Tape sample cassettes to sheet bubbles and place in a container that will cushion the samples without rattling.

5.3.3. To avoid the possibility of sample contamination, always ship bulk samples in separate mailing containers.

6. Analysis

6.1. Safety Precautions

6.1.1. Acetone is extremely flammable and precautions must be taken not to ignite it. Avoid using large containers or quantities of acetone. Transfer the solvent in a ventilated laboratory hood. Do not use acetone near any open flame. For generation of acetone vapor, use a spark free heat source.

6.1.2. Any asbestos spills should be cleaned up immediately to prevent dispersal of fibers. Prudence should be exercised to avoid contamination of laboratory facilities or exposure of personnel to asbestos. Asbestos spills should be cleaned up with wet methods and/ or a High Efficiency Particulate-Air (HEPA) filtered vacuum.

CAUTION: Do not use a vacuum without a HEPA filter -- It will disperse fine asbestos fibers in the air.

6.2. Equipment

6.2.1. Phase contrast microscope with binocular or trinocular head.

6.2.2. Widefield or Huygenian 10X eyepieces (NOTE: The eyepiece containing the graticule must be a focusing eyepiece. Use a 40X phase objective with a numerical aperture of 0.65 to 0.75).

6.2.3. Kohler illumination (if possible) with green or blue filter.

6.2.4. Walton-Beckett Graticule, type G-22 with 100 plus or minus 2 um projected diameter.

6.2.5. Mechanical stage. A rotating mechanical stage is convenient for use with polarized light.

6.2.6. Phase telescope.

6.2.7. Stage micrometer with 0.01-mm subdivisions.

6.2.8. Phase-shift test slide, mark II (Available from PTR optics Ltd., and also McCrone).

6.2.9. Precleaned glass slides, 25 mm X 75 mm. One end can be frosted for convenience in writing sample numbers, etc., or paste-on labels can be used.

6.2.10. Cover glass #1 1/2.

6.2.11. Scalpel (#10, curved blade).

6.2.12. Fine tipped forceps.

6.2.13. Aluminum block for clearing filter (see Appendix D and Figure 4).

6.2.14. Automatic adjustable pipette, 100- to 500-uL.

6.2.15. Micropipette, 5 uL.

6.3. Reagents

6.3.1. Acetone (HPLC grade).

6.3.2. Triacetin (glycerol triacetate).

6.3.3. Lacquer or nail polish.

6.4. Standard Preparation

A way to prepare standard asbestos samples of known concentration has not been developed. It is possible to prepare replicate samples of nearly equal concentration. This has been performed through the PAT program. These asbestos samples are distributed by the AIHA to participating laboratories.

Since only about one-fourth of a 25-mm sample membrane is required for an asbestos count, any PAT sample can serve as a "standard" for replicate counting.

6.5. Sample Mounting Note: See Safety Precautions in Section

6.1. before proceeding. The objective is to produce samples with a smooth (non-grainy) background in a medium with a refractive index of approximately 1.46. The technique below collapses the filter for easier focusing and produces permanent mounts which are useful for quality control and interlaboratory comparison.

An aluminum block or similar device is required for sample preparation.

6.5.1. Heat the aluminum block to about 70 deg.C. The hot block should not be used on any surface that can be damaged by either the heat or from exposure to acetone.

6.5.2. Ensure that the glass slides and cover glasses are free of dust and fibers.

6.5.3. Remove the top plug to prevent a vacuum when the cassette is opened. Clean the outside of the cassette if necessary. Cut the seal and/or tape on the cassette with a razor blade. Very carefully separate the base from the extension cowl, leaving the filter and backup pad in the base.

6.5.4. With a rocking motion cut a triangular wedge from the filter using the scalpel. This wedge should be one-sixth to one- fourth of the filter. Grasp the filter wedge with the forceps on the perimeter of the filter which was clamped between the cassette pieces. DO NOT TOUCH the filter with your finger. Place the filter on the glass slide sample side up. Static electricity will usually keep the filter on the slide until it is cleared.

6.5.5. Place the tip of the micropipette containing about 200 uL acetone into the aluminum block. Insert the glass slide into the receiving slot in the aluminum block. Inject the acetone into the block with slow, steady pressure on the plunger while holding the pipette firmly in place. Wait 3 to 5 seconds for the filter to clear, then remove the pipette and slide from the aluminum block.

6.5.6. Immediately (less than 30 seconds) place 2.5 to 3.5 uL of triacetin on the filter (NOTE: Waiting longer than 30 seconds will result in increased index of refraction and decreased contrast between the fibers and the preparation. This may also lead to separation of the cover slip from the slide).

6.5.7. Lower a cover slip gently onto the filter at a slight angle to reduce the possibility of forming air bubbles. If more than 30 seconds have elapsed between acetone exposure and triacetin application, glue the edges of the cover slip to the slide with lacquer or nail polish.

6.5.8. If clearing is slow, warm the slide for 15 min on a hot plate having a surface temperature of about 50 deg.C to hasten clearing. The top of the hot block can be used if the slide is not heated too long.

6.5.9. Counting may proceed immediately after clearing and mounting are completed.

6.6. Sample Analysis

Completely align the microscope according to the manufacturer's instructions. Then, align the microscope using the following general alignment routine at the beginning of every counting session and more often if necessary.

6.6.1. Alignment

(1) Clean all optical surfaces. Even a small amount of dirt can significantly degrade the image.

(2) Rough focus the objective on a sample.

(3) Close down the field iris so that it is visible in the field of view. Focus the image of the iris with the condenser focus. Center the image of the iris in the field of view.

(4) Install the phase telescope and focus on the phase rings. Critically center the rings. Misalignment of the rings results in astigmatism which will degrade the image.

(5) Place the phase-shift test slide on the microscope stage and focus on the lines. The analyst must see line set 3 and should see at least parts of 4 and 5 but, not see line set 6 or 6. A microscope/microscopist combination which does not pass this test may not be used.

6.6.2. Counting Fibers

(1) Place the prepared sample slide on the mechanical stage of the microscope. Position the center of the wedge under the objective lens and focus upon the sample.

(2) Start counting from one end of the wedge and progress along a radial line to the other end (count in either direction from perimeter to wedge tip). Select fields randomly, without looking into the eyepieces, by slightly advancing the slide in one direction with the mechanical stage control.

(3) Continually scan over a range of focal planes (generally the upper 10 to 15 um of the filter surface) with the fine focus control during each field count. Spend at least 5 to 15 seconds per field.

(4) Most samples will contain asbestos fibers with fiber diameters less than 1 um. Look carefully for faint fiber images. The small diameter fibers will be very hard to see. However, they are an important contribution to the total count.

(5) Count only fibers equal to or longer than 5 um. Measure the length of curved fibers along the curve.

(6) Count fibers which have a length to width ratio of 3:1 or greater.

(7) Count all the fibers in at least 20 fields. Continue counting until either 100 fibers are counted or 100 fields have been viewed; whichever occurs first. Count all the fibers in the final field.

(8) Fibers lying entirely within the boundary of the Walton- Beckett graticule field shall receive a count of 1. Fibers crossing the boundary once, having one end within the circle shall receive a count of 1/2. Do not count any fiber that crosses the graticule boundary more than once. Reject and do not count any other fibers even though they may be visible outside the graticule area. If a fiber touches the circle, it is considered to cross the line.

(9) Count bundles of fibers as one fiber unless individual fibers can be clearly identified and each individual fiber is clearly not connected to another counted fiber. See Figure 2 for counting conventions.

(10) Record the number of fibers in each field in a consistent way such that filter non-uniformity can be assessed.

(11) Regularly check phase ring alignment.

(12) When an agglomerate (mass of material) covers more than 25% of the field of view, reject the field and select another. Do not include it in the number of fields counted.

(13) Perform a "blind recount" of 1 in every 10 filter wedges (slides). Re-label the slides using a person other than the original counter.

6.7. Fiber Identification

As previously mentioned in Section 1.3., PCM does not provide positive confirmation of asbestos fibers. Alternate differential counting techniques should be used if discrimination is desirable. Differential counting may include primary discrimination based on morphology, polarized light analysis of fibers, or modification of PCM data by Scanning Electron or Transmission Electron Microscopy.

A great deal of experience is required to routinely and correctly perform differential counting. It is discouraged unless it is legally necessary. Then, only if a fiber is obviously not asbestos should it be excluded from the count. Further discussion of this technique can be found in reference 8.10.

If there is a question whether a fiber is asbestos or not, follow the rule:

"WHEN IN DOUBT, COUNT."

6.8. Analytical Recommendations -- Quality Control System

6.8.1. All individuals performing asbestos analysis must have taken the NIOSH course for sampling and evaluating airborne asbestos or an equivalent course.

6.8.2. Each laboratory engaged in asbestos counting shall set up a slide trading arrangement with at least two other laboratories in order to compare performance and eliminate inbreeding of error. The slide exchange occurs at least semiannually. The round robin results shall be posted where all analysts can view individual analyst's results.

6.8.3. Each laboratory engaged in asbestos counting shall participate in the Proficiency Analytical Testing Program, the Asbestos Analyst Registry or equivalent.

6.8.4. Each analyst shall select and count prepared slides from a "slide bank". These are quality assurance counts. The slide bank shall be prepared using uniformly distributed samples taken from the workload. Fiber densities should cover the entire range routinely analyzed by the laboratory. These slides are counted blind by all counters to establish an original standard deviation. This historical distribution is compared with the quality assurance counts. A counter must have 95% of all quality control samples counted within three standard deviations of the historical mean. This count is then integrated into a new historical mean and standard deviation for the slide.

The analyses done by the counters to establish the slide bank may be used for an interim quality control program if the data are treated in a proper statistical fashion.

7. Calculations

7.1. Calculate the estimated airborne asbestos fiber concentration on the filter sample using the following formula:

(For Formula, see paper copy)
where:
AC = Airborne fiber concentration
FB = Total number of fibers greater than 5 um counted
FL = Total number of fields counted on the filter
BFB = Total number of fibers greater than 5 um counted in the blank
BFL = Total number of fields counted on the blank
ECA = Effective collecting area of filter (385 mm(2) nominal for a 25 - mm filter.)
FR = Pump flow rate (L/min)
MFA = Microscope count field area (mm(2)). This is 0.00785 mm(2) for a Walton-Beckett Graticule
T = Sample collection time (min)
1,000 = Conversion of L to cc

Note: The collection area of a filter is seldom equal to 385 mm(2). It is appropriate for laboratories to routinely monitor the exact diameter using an inside micrometer. The collection area is calculated according to the formula:

Area = Pie(d/2)(2)

7.2. Short-Cut Calculation

Since a given analyst always has the same interpupillary distance, the number of fields per filter for a particular analyst will remain constant for a given size filter. The field size for that analyst is constant (i.e. the analyst is using an assigned microscope and is not changing the reticle).

For example, if the exposed area of the filter is always 385 mm(2) and the size of the field is always 0.00785 mm(2) the number of fields per filter will always be 49,000. In addition it is necessary to convert liters of air to cc. These three constants can then be combined such that ECA/(1,000 x MFA)=49. The previous equation simplifies to:

 

(For Equation, see paper copy)

 

7.3. Recount Calculations

As mentioned in step 13 of Section 6.6.2., a "blind recount" of 10% of the slides is performed. In all cases, differences will be observed between the first and second counts of the same filter wedge. Most of these differences will be due to chance alone, that is, due to the random variability (precision) of the count method. Statistical recount criteria enables one to decide whether observed differences can be explained due to chance alone or are probably due to systematic differences between analysts, microscopes, or other biasing factors.

The following recount criterion is for a pair of counts that estimate AC in fibers/cc. The criterion is given at the type-I error level. That is, there is 5% maximum risk that we will reject a pair of counts for the reason that one might be biased, when the large observed difference is really due to chance.

Reject a pair of counts if:

(For Equation, see paper copy)

Where:

AC(1) = lower estimated airborne fiber concentration
AC(2) = higher estimated airborne fiber concentration
AC(avg) = average of the two concentration estimates
CV(FB) = CV for the average of the two concentration estimates

If a pair of counts are rejected by this criterion then, recount the rest of the filters in the submitted set. Apply the test and reject any other pairs failing the test. Rejection shall include a memo to the industrial hygienist stating that the sample failed a statistical test for homogeneity and the true air concentration may be significantly different than the reported value.

7.4. Reporting Results

Report results to the industrial hygienist as fibers/cc. Use two significant figures. If multiple analyses are performed on a sample, an average of the results is to be reported unless any of the results can be rejected for cause.

8. References

8.1. Dreesen, W.C., et al., U.S. Public Health Service: A Study of Asbestosis in the Asbestos Textile Industry (Public Health Bulletin No. 241), U.S. Treasury Dept., Washington, DC, 1938.

8.2. Asbestos Research Council: The Measurement of Airborne Asbestos Dust by the Membrane Filter Method (Technical Note), Asbestos Research Council, Rockdale, Lancashire, Great Britain, 1969.

8.3. Bayer, S.G., Zumwalde, R.D., Brown, T.A., Equipment and Procedure for Mounting Millipore Filters and Counting Asbestos Fibers by Phase Contrast Microscopy, Bureau of Occupational Health, U.S. Dept. of Health, Education and Welfare, Cincinnati, OH, 1969.

8.4. NIOSH Manual of Analytical Methods, 2nd ed., Vol. 1 (DHEW/ NIOSH Pub. No. 77-157-A). National Institute for Occupational Safety and Health, Cincinnati, OH, 1977. pp. 239-1 -- 239-21.

8.5. Asbestos, Code of Federal Regulations 29 CFR 1910.1001. 1971.

8.6. Occupational Exposure to Asbestos, Tremolite, Anthophyllite, and Actinolite. Final Rule, Federal Register 51:119 (20 June 1986). pp. 22612-22790.

8.7. Asbestos, Tremolite, Anthophyllite, and Actinolite, Code of Federal Regulations 1910.1001. 1988. pp. 711-752.

8.8. Criteria for a Recommended Standard -- Occupational Exposure to Asbestos (DHEW/NIOSH Pub. No. HSM 72-10267), National Institute for Occupational Safety and Health, NIOSH, Cincinnati, OH, 1972. pp. III-1 -- III-24.

8.9. Leidel, N.A., Bayer, S.G., Zumwalde, R.D., Busch, K.A., USPHS/NIOSH Membrane Filter Method for Evaluating Airborne Asbestos Fibers (DHEW/NIOSH Pub. No. 79-127). National Institute for Occupational Safety and Health, Cincinnati, OH, 1979.

8.10. Dixon, W.C., Applications of Optical Microscopy in Analysis of Asbestos and Quartz, Analytical Techniques in Occupational Health Chemistry, edited by D.D. Dollberg and A.W. Verstuyft. Wash. D.C.: American Chemical Society, (ACS Symposium Series 120) 1980. pp. 13-41.

Quality Control

The OSHA asbestos regulations require each laboratory to establish a quality control program. The following is presented as an example of how the OSHA-SLTC constructed its internal CV curve as part of meeting this requirement. Data for the CV curve shown below is from 395 samples collected during OSHA compliance inspections and analyzed from October 1980 through April 1986.

Each sample was counted by 2 to 5 different counters independently of one another. The standard deviation and the CV statistic was calculated for each sample. This data was then plotted on a graph of CV vs. fibers/mm(2). A least squares regression was performed using the following equation:

CV = antilog(10) [(log(10)(x))(2) + B(log(10)(x)) + C]

where: x = the number of fibers/mm(2) Application of least squares gave:

A = 0.182205 B = 0.973343 C = 0.327499

Using these values, the equation becomes:

CV = antilog(10) [0.182205(log(10)(x))(2)

- 0.973343(log(10)(x)) + 0.327499]

Sampling Pump Flow Rate Corrections

This correction is used if a difference greater than 5% in ambient temperature and/or pressure is noted between calibration and sampling sites and the pump does not compensate for the differences.

(For Equation, see paper copy)

Where:
Q(act) = actual flow rate
Q(cal) = calibrated flow rate (if a rotameter was used, the rotameter value)
P(cal) = uncorrected air pressure at calibration
P(act) = uncorrected air pressure at sampling site
T(act) = temperature at sampling site (K)
T(cal) = temperature at calibration (K)

Walton-Beckett Graticule

When ordering the Graticule for asbestos counting, specify the exact disc diameter needed to fit the ocular of the microscope and the diameter (mm) of the circular counting area. Instructions for measuring the dimensions necessary are listed:

(1) Insert any available graticule into the focusing eyepiece and focus so that the graticule lines are sharp and clear.

(2) Align the microscope.

(3) Place a stage micrometer on the microscope object stage and focus the microscope on the graduated lines.

(4) Measure the magnified grid length, PL (um), using the stage micrometer.

(5) Remove the graticule from the microscope and measure its actual grid length, AL (mm). This can be accomplished by using a mechanical stage fitted with verniers, or a jeweler's loupe with a direct reading scale.

(6) Let D = 100 um. Calculate the circle diameter, d(c)(mm), for the Walton-Beckett graticule and specify the diameter when making a purchase:

d(c) = AL x D
-- -- -- -- -- --
PL

Example: If PL = 108 um, AL = 2.93 mm and D = 100 um, then,

d(c) = 2.93 x 100
-- -- -- -- -- -- --
108
= 2.71mm

(7) Each eyepiece-objective-reticle combination on the microscope must be calibrated. Should any of the three be changed (by zoom adjustment, disassembly, replacement, etc.), the combination must be recalibrated. Calibration may change if interpupillary distance is changed.

Measure the field diameter, D (acceptable range: 100 plus or minus 2 um) with a stage micrometer upon receipt of the graticule from the manufacturer. Determine the field area (mm(2)).

Field Area = Pie(D/2)(2) If D = 100 um = 0.1 mm, then Field Area = Pie(0.1 mm/2)(2) = 0.00785mm(2)

The Graticule is available from: Graticules Ltd., Morley Road, Tonbridge TN9 IRN, Kent, England (Telephone 011-44-732-359061). Also available from PTR Optics Ltd., 145 Newton Street, Waltham, MA 02154 [telephone (617) 891-6000] or McCrone Accessories and Components, 2506 S. Michigan Ave., Chicago, IL 60616 [phone (312)-842-7100]. The graticule is custom made for each microscope.

(For Figure 1 Walton-Beckett Graticule with some
explanatory fibers, see paper copy)

Counts for the Fibers in the Figure
Structure No Count Explanation
1 to 6 1 Single fibers all contained within the Circle
7 1/2 Fiber crosses circle once
8 0 Fiber too short
9 2 Two crossing fibers
10 0 Fiber outside graticule
11 0 Fiber crosses graticule twice
12 1/2 Although split, fiber only crosses once

 

Appendix D to 1926.1101 [Amended]

9. Appendix D to 1926.1101 is revised to read as follows:

This mandatory appendix contains the medical questionnaires that must be administered to all employees who are exposed to asbestos above the permissible exposure limit, and who will therefore be included in their employer's medical surveillance program.* * *

10. Appendix F to 1926.1101 is revised to read as follows:

Appendix F to 1926.1101. Work Practices and Engineering Controls for Class I Asbestos Operations. -- Non-mandatory

This is a non-mandatory appendix to the asbestos standards for construction and for shipyards. It describes criteria and procedures for erecting and using negative pressure enclosures for Class I Asbestos Work, when NPEs are used as an allowable control method to comply with paragraph (g)(5)(i) of this section. Many small and variable details are involved in the erection of a negative pressure enclosure. OSHA and most participants in the rulemaking agreed that only the major, more performance oriented criteria should be made mandatory. These criteria are set out in paragraph (g) of this section. In addition, this appendix includes these mandatory specifications and procedures in its guidelines in order to make this appendix coherent and helpful. The mandatory nature of the criteria which appear in the regulatory text is not changed because they are included in this "non-mandatory" appendix. Similarly, the additional criteria and procedures included as guidelines in the appendix, do not become mandatory because mandatory criteria are also included in these comprehensive guidelines.

In addition, none of the criteria, both mandatory and recommended, are meant to specify or imply the need for use of patented or licensed methods or equipment. Recommended specifications included in this attachment should not discourage the use of creative alternatives which can be shown to reliably achieve the objectives of negative-pressure enclosures.

Requirements included in this appendix, cover general provisions to be followed in all asbestos jobs, provisions which must be followed for all Class I asbestos jobs, and provisions governing the construction and testing of negative pressure enclosures. The first category includes the requirement for use of wet methods, HEPA vacuums, and immediate bagging of waste; Class I work must conform to the following provisions:

* oversight by competent person * use of critical barriers over all openings to work area * isolation of HVAC systems * use of impermeable dropcloths and coverage of all objects within regulated areas In addition, more specific requirements for NPEs include: * maintenance of -0.02 inches water gauge within enclosure * manometric measurements * air movement away from employees performing removal work * smoke testing or equivalent for detection of leaks and air direction * deactivation of electrical circuits, if not provided with ground-fault circuit interrupters.

Planning the Project

The standard requires that an exposure assessment be conducted before the asbestos job is begun [Sec. 1926.1101 (f)(1)]. Information needed for that assessment, includes data relating to prior similar jobs, as applied to the specific variables of the current job. The information needed to conduct the assessment will be useful in planning the project, and in complying with any reporting requirements under this standard, when significant changes are being made to a control system listed in the standard, [see also those of USEPA (40 CFR 61, subpart M). Thus, although the standard does not explicitly require the preparation of a written asbestos removal plan, the usual constituents of such a plan, i.e., a description of the enclosure, the equipment, and the procedures to be used throughout the project, must be determined before the enclosure can be erected. The following information should be included in the planning of the system:

A physical description of the work area; A description of the approximate amount of material to be removed; A schedule for turning off and sealing existing ventilation systems; Personnel hygiene procedures; A description of personal protective equipment and clothing to be worn by employees;

A description of the local exhaust ventilation systems to be used and how they are to be tested;

A description of work practices to be observed by employees; An air monitoring plan; A description of the method to be used to transport waste material; and The location of the dump site.

Materials and Equipment Necessary for Asbestos Removal

Although individual asbestos removal projects vary in terms of the equipment required to accomplish the removal of the materials, some equipment and materials are common to most asbestos removal operations.

Plastic sheeting used to protect horizontal surfaces, seal HVAC openings or to seal vertical openings and ceilings should have a minimum thickness of 6 mils. Tape or other adhesive used to attach plastic sheeting should be of sufficient adhesive strength to support the weight of the material plus all stresses encountered during the entire duration of the project without becoming detached from the surface.

Other equipment and materials which should be available at the beginning of each project are:

-- HEPA Filtered Vacuum is essential for cleaning the work area after the asbestos has been removed. It should have a long hose capable of reaching out-of-the-way places, such as areas above ceiling tiles, behind pipes, etc.

-- Portable air ventilation systems installed to provide the negative air pressure and air removal from the enclosure must be equipped with a HEPA filter. The number and capacity of units required to ventilate an enclosure depend on the size of the area to be ventilated. The filters for these systems should be designed in such a manner that they can be replaced when the air flow volume is reduced by the build-up of dust in the filtration material. Pressure monitoring devices with alarms and strip chart recorders attached to each system to indicate the pressure differential and the loss due to dust buildup on the filter are recommended.

-- Water sprayers should be used to keep the asbestos material as saturated as possible during removal; the sprayers will provide a fine mist that minimizes the impact of the spray on the material.

-- Water used to saturate the asbestos containing material can be amended by adding at least 15 milliliters (1/4 ounce) of wetting agent in 1 liter (1 pint) of water. An example of a wetting agent is a 50/50 mixture of polyoxyethylene ether and polyoxyethylene polyglycol ester.

-- Backup power supplies are recommended, especially for ventilation systems.

-- Shower and bath water should be with mixed hot and cold water faucets. Water that has been used to clean personnel or equipment should either be filtered or be collected and discarded as asbestos waste. Soap and shampoo should be provided to aid in removing dust from the workers' skin and hair.

-- See paragraphs (h) and (i) of this section for appropriate respiratory protection and protective clothing.

-- See paragraph (k) of this section for required signs and labels.

Preparing the Work Area

Disabling HVAC Systems: The power to the heating, ventilation, and air conditioning systems that service the restricted area must be deactivated and locked off. All ducts, grills, access ports, windows and vents must be sealed off with two layers of plastic to prevent entrainment of contaminated air.

Operating HVAC Systems in the Restricted Area: If components of a HVAC system located in the restricted area are connected to a system that will service another zone during the project, the portion of the duct in the restricted area must be sealed and pressurized. Necessary precautions include caulking the duct joints, covering all cracks and openings with two layers of sheeting, and pressurizing the duct throughout the duration of the project by restricting the return air flow. The power to the fan supplying the positive pressure should be locked "on" to prevent pressure loss.

Sealing Elevators: If an elevator shaft is located in the restricted area, it should be either shut down or isolated by sealing with two layers of plastic sheeting. The sheeting should provide enough slack to accommodate the pressure changes in the shaft without breaking the air-tight seal.

Removing Mobile Objects: All movable objects should be cleaned and removed from the work area before an enclosure is constructed unless moving the objects creates a hazard. Mobile objects will be assumed to be contaminated and should be either cleaned with amended water and a HEPA vacuum and then removed from the area or wrapped and then disposed of as hazardous waste.

Cleaning and Sealing Surfaces: After cleaning with water and a HEPA vacuum, surfaces of stationary objects should be covered with two layers of plastic sheeting. The sheeting should be secured with duct tape or an equivalent method to provide a tight seal around the object.

Bagging Waste: In addition to the requirement for immediate bagging of waste for disposal, it is further recommended that the waste material be double-bagged and sealed in plastic bags designed for asbestos disposal. The bags should be stored in a waste storage area that can be controlled by the workers conducting the removal. Filters removed from air handling units and rubbish removed from the area are to be bagged and handled as hazardous waste.

Constructing the Enclosure

The enclosure should be constructed to provide an air-tight seal around ducts and openings into existing ventilation systems and around penetrations for electrical conduits, telephone wires, water lines, drain pipes, etc. Enclosures should be both airtight and watertight except for those openings designed to provide entry and/ or air flow control.

Size: An enclosure should be the minimum volume to encompass all of the working surfaces yet allow unencumbered movement by the worker(s), provide unrestricted air flow past the worker(s), and ensure walking surfaces can be kept free of tripping hazards.

Shape: The enclosure may be any shape that optimizes the flow of ventilation air past the worker(s).

Structural Integrity: The walls, ceilings and floors must be supported in such a manner that portions of the enclosure will not fall down during normal use.

Openings: It is not necessary that the structure be airtight; openings may be designed to direct air flow. Such openings should be located at a distance from active removal operations. They should be designed to draw air into the enclosure under all anticipated circumstances. In the event that negative pressure is lost, they should be fitted with either HEPA filters to trap dust or automatic trap doors that prevent dust from escaping the enclosure. Openings for exits should be controlled by an airlock or a vestibule.

Barrier Supports: Frames should be constructed to support all unsupported spans of sheeting.

Sheeting: Walls, barriers, ceilings, and floors should be lined with two layers of plastic sheeting having a thickness of at least 6 mil.

Seams: Seams in the sheeting material should be minimized to reduce the possibilities of accidental rips and tears in the adhesive or connections. All seams in the sheeting should overlap, be staggered and not be located at corners or wall-to-floor joints. Areas Within an Enclosure: Each enclosure consists of a work area, a decontamination area, and waste storage area. The work area where the asbestos removal operations occur should be separated from both the waste storage area and the contamination control area by physical curtains, doors, and/or airflow patterns that force any airborne contamination back into the work area.

See paragraph (j) of this section for requirements for hygiene facilities.

During egress from the work area, each worker should step into the equipment room, clean tools and equipment, and remove gross contamination from clothing by wet cleaning and HEPA vacuuming. Before entering the shower area, foot coverings, head coverings, hand coverings, and coveralls are removed and placed in impervious bags for disposal or cleaning. Airline connections from airline respirators with HEPA disconnects and power cables from powered air- purifying respirators (PAPRs) will be disconnected just prior to entering the shower room.

Establishing Negative Pressure Within the Enclosure

Negative Pressure: Air is to be drawn into the enclosure under all anticipated conditions and exhausted through a HEPA filter for 24 hours a day during the entire duration of the project.

Air Flow Tests: Air flow patterns will be checked before removal operations begin, at least once per operating shift and any time there is a question regarding the integrity of the enclosure. The primary test for air flow is to trace air currents with smoke tubes or other visual methods. Flow checks are made at each opening and at each doorway to demonstrate that air is being drawn into the enclosure and at each worker's position to show that air is being drawn away from the breathing zone.

Monitoring Pressure Within the Enclosure: After the initial air flow patterns have been checked, the static pressure must be monitored within the enclosure. Monitoring may be made using manometers, pressure gauges, or combinations of these devices. It is recommended that they be attached to alarms and strip chart recorders at points identified by the design engineer.

Corrective Actions: If the manometers or pressure gauges demonstrate a reduction in pressure differential below the required level, work should cease and the reason for the change investigated and appropriate changes made. The air flow patterns should be retested before work begins again.

Pressure Differential: The design parameters for static pressure differentials between the inside and outside of enclosures typically range from 0.02 to 0.10 inches of water gauge, depending on conditions. All zones inside the enclosure must have less pressure than the ambient pressure outside of the enclosure (-0.02 inches water gauge differential). Design specifications for the differential vary according to the size, configuration, and shape of the enclosure as well as ambient and mechanical air pressure conditions around the enclosure.

Air Flow Patterns: The flow of air past each worker shall be enhanced by positioning the intakes and exhaust ports to remove contaminated air from the worker's breathing zone, by positioning HEPA vacuum cleaners to draw air from the worker's breathing zone, by forcing relatively uncontaminated air past the worker toward an exhaust port, or by using a combination of methods to reduce the worker's exposure.

Air Handling Unit Exhaust: The exhaust plume from air handling units should be located away from adjacent personnel and intakes for HVAC systems.

Air Flow Volume: The air flow volume (cubic meters per minute) exhausted (removed) from the workplace must exceed the amount of makeup air supplied to the enclosure. The rate of air exhausted from the enclosure should be designed to maintain a negative pressure in the enclosure and air movement past each worker. The volume of air flow removed from the enclosure should replace the volume of the container at every 5 to 15 minutes. Air flow volume will need to be relatively high for large enclosures, enclosures with awkward shapes, enclosures with multiple openings, and operations employing several workers in the enclosure.

Air Flow Velocity: At each opening, the air flow velocity must visibly "drag" air into the enclosure. The velocity of air flow within the enclosure must be adequate to remove airborne contamination from each worker's breathing zone without disturbing the asbestos-containing material on surfaces.

Airlocks: Airlocks are mechanisms on doors and curtains that control the air flow patterns in the doorways. If air flow occurs, the patterns through doorways must be such that the air flows toward the inside of the enclosure. Sometimes vestibules, double doors, or double curtains are used to prevent air movement through the doorways. To use a vestibule, a worker enters a chamber by opening the door or curtain and then closing the entry before opening the exit door or curtain.

Airlocks should be located between the equipment room and shower room, between the shower room and the clean room, and between the waste storage area and the outside of the enclosure. The air flow between adjacent rooms must be checked using smoke tubes or other visual tests to ensure the flow patterns draw air toward the work area without producing eddies.

Monitoring for Airborne Concentrations

In addition to the breathing zone samples taken as outlined in paragraph (f) of this section, samples of air should be taken to demonstrate the integrity of the enclosure, the cleanliness of the clean room and shower area, and the effectiveness of the HEPA filter. If the clean room is shown to be contaminated, the room must be relocated to an uncontaminated area.

Samples taken near the exhaust of portable ventilation systems must be done with care.

General Work Practices

Preventing dust dispersion is the primary means of controlling the spread of asbestos within the enclosure. Whenever practical, the point of removal should be isolated, enclosed, covered, or shielded from the workers in the area. Waste asbestos containing materials must be bagged during or immediately after removal; the material must remain saturated until the waste container is sealed.

Waste material with sharp points or corners must be placed in hard air-tight containers rather than bags.

Whenever possible, large components should be sealed in plastic sheeting and removed intact.

Bags or containers of waste will be moved to the waste holding area, washed, and wrapped in a bag with the appropriate labels.

Cleaning the Work Area

Surfaces within the work area should be kept free of visible dust and debris to the extent feasible. Whenever visible dust appears on surfaces, the surfaces within the enclosure must be cleaned by wiping with a wet sponge, brush, or cloth and then vacuumed with a HEPA vacuum.

All surfaces within the enclosure should be cleaned before the exhaust ventilation system is deactivated and the enclosure is disassembled. An approved encapsulate may be sprayed onto areas after the visible dust has been removed.

11. Appendix G to Sec. 1926.1101 is removed and reserved.

12. Appendix H of Sec. 1926.1101 is revised to read as follows:

Appendix H to 1915.1001 -- Substance Technical Information for Asbestos. Non-Mandatory

I. Substance Identification

A. Substance: "Asbestos" is the name of a class of magnesium- silicate minerals that occur in fibrous form. Minerals that are included in this group are chrysotile, crocidolite, amosite, anthophyllite asbestos, tremolite asbestos, and actinolite asbestos.

B. Asbestos is and was used in the manufacture of heat-resistant clothing, automotive brake and clutch linings, and a variety of building materials including floor tiles, roofing felts, ceiling tiles, asbestos-cement pipe and sheet, and fire-resistant drywall. Asbestos is also present in pipe and boiler insulation materials and in sprayed-on materials located on beams, in crawlspaces, and between walls.

C. The potential for an asbestos-containing product to release breathable fibers depends largely on its degree of friability. Friable means that the material can be crumbled with hand pressure and is therefore likely to emit fibers. The fibrous fluffy sprayed- on materials used for fireproofing, insulation, or sound proofing are considered to be friable, and they readily release airborne fibers if disturbed. Materials such as vinyl-asbestos floor tile or roofing felt are considered non-friable if intact and generally do not emit airborne fibers unless subjected to sanding, sawing and other aggressive operations. Asbestos-cement pipe or sheet can emit airborne fibers if the materials are cut or sawed, or if they are broken.

D. Permissible exposure: Exposure to airborne asbestos fibers may not exceed 0.1 fibers per cubic centimeter of air (0.1 f/cc) averaged over the 8-hour workday, and 1 fiber per cubic centimeter of air (1.0 f/cc) averaged over a 30 minute work period.

II. Health Hazard Data

A. Asbestos can cause disabling respiratory disease and various types of cancers if the fibers are inhaled. Inhaling or ingesting fibers from contaminated clothing or skin can also result in these diseases. The symptoms of these diseases generally do not appear for 20 or more years after initial exposure.

B. Exposure to asbestos has been shown to cause lung cancer, mesothelioma, and cancer of the stomach and colon. Mesothelioma is a rare cancer of the thin membrane lining of the chest and abdomen. Symptoms of mesothelioma include shortness of breath, pain in the walls of the chest, and/or abdominal pain.

III. Respirators and Protective Clothing

A. Respirators: You are required to wear a respirator when performing tasks that result in asbestos exposure that exceeds the permissible exposure limit (PEL) of 0.1 f/cc and when performing certain designated operations. Air-purifying respirators equipped with a high-efficiency particulate air (HEPA) filter can be used where airborne asbestos fiber concentrations do not exceed 1.0 f/cc; otherwise, more protective respirators such as air-supplied, positive-pressure, full facepiece respirators must be used. Disposable respirators or dust masks are not permitted to be used for asbestos work. For effective protection, respirators must fit your face and head snugly. Your employer is required to conduct fit test when you are first assigned a respirator and every 6 months thereafter. Respirators should not be loosened or removed in work situations where their use is required.

B. Protective Clothing: You are required to wear protective clothing in work areas where asbestos fiber concentrations exceed the permissible exposure limit (PEL) of 0.1 f/cc.

IV. Disposal Procedures and Clean-up

A. Wastes that are generated by processes where asbestos is present include:

1. Empty asbestos shipping containers.

2. Process wastes such as cuttings, trimmings, or reject materials.

3. Housekeeping waste from wet-sweeping or HEPA-vacuuming.

4. Asbestos fireproofing or insulating material that is removed from buildings.

5. Asbestos-containing building products removed during building renovation or demolition.

6. Contaminated disposable protective clothing.

B. Empty shipping bags can be flattened under exhaust hoods and packed into airtight containers for disposal. Empty shipping drums are difficult to clean and should be sealed.

C. Vacuum bags or disposable paper filters should not be cleaned, but should be sprayed with a fine water mist and placed into a labeled waste container.

D. Process waste and housekeeping waste should be wetted with water or a mixture of water and surfactant prior to packaging in disposable containers.

E. Asbestos-containing material that if removed from buildings must be disposed of in leak-tight 6-mil plastic bags, plastic-lined cardboard containers, or plastic-lined metal containers. These wastes, which are removed while wet, should be sealed in containers before they dry out to minimize the release of asbestos fibers during handling.

V. Access to Information

A. Each year, your employer is required to inform you of the information contained in this standard and appendices for asbestos. In addition, your employer must instruct you in the proper work practices for handling asbestos-containing materials, and the correct use of protective equipment.

B. Your employer is required to determine whether you are being exposed to asbestos. Your employer must treat exposure to thermal system insulation and sprayed-on and trowled-on surfacing material as asbestos exposure, unless results of laboratory analysis show that the material does not contain asbestos. You or your representative has the right to observe employee measurements and to record the results obtained. Your employer is required to inform you of your exposure, and, if you are exposed above the permissible exposure limit, he or she is required to inform you of the actions that are being taken to reduce your exposure to within the permissible limit.

C. Your employer is required to keep records of your exposures and medical examinations. These exposure records must be kept for at least thirty (30) years. Medical records must be kept for the period of your employment plus thirty (30) years.

D. Your employer is required to release your exposure and medical records to your physician or designated representative upon your written request.

Appendix I of 1926.1101 [Amended]

13. Appendix I of Sec. 1926.1101 is amended by revising the first sentence of the second paragraph of section IV. entitled Surveillance and Preventive Consideration to read as follows:

* * * * *

The employer is required to institute a medical surveillance program for all employees who are or will be exposed to asbestos at or above the permissible exposure limit (0.1 fiber per cubic centimeter of air). * * * * * * * *

14. Appendix K to Sec. 1926.1101 is added to read as follows:

Appendix K to 1926.1101 -- Polarized Light Microscopy of Asbestos (Non-Mandatory)

Method number: ID-191 Matrix: Bulk Collection Procedure: Collect approximately 1 to 2 grams of each type of material and place into separate 20 mL scintillation vials.

Analytical Procedure: A portion of each separate phase is analyzed by gross examination, phase-polar examination, and central stop dispersion microscopy.

Commercial manufacturers and products mentioned in this method are for descriptive use only and do not constitute endorsements by USDOL-OSHA. Similar products from other sources may be substituted.

1. Introduction

This method describes the collection and analysis of asbestos bulk materials by light microscopy techniques including phase- polar illumination and central-stop dispersion microscopy. Some terms unique to asbestos analysis are defined below:

Amphibole: A family of minerals whose crystals are formed by long, thin units which have two thin ribbons of double chain silicate with a brucite ribbon in between. The shape of each unit is similar to an "I beam". Minerals important in asbestos analysis include cummingtonite-grunerite, crocidolite, tremolite-actinolite and anthophyllite.

Asbestos: A term for naturally occurring fibrous minerals. Asbestos includes chrysotile, cummingtonite-grunerite asbestos (amosite), anthophyllite asbestos, tremolite asbestos, crocidolite, actinolite asbestos and any of these minerals which have been chemically treated or altered. The precise chemical formulation of each species varies with the location from which it was mined. Nominal compositions are listed:

Chrysotile..................... Mg(3)Si(2)O(5)(OH)(4)

Crocidolite (Riebeckite asbestos) ............................. Na(2)Fe(3)(2) + Fe(2)(3) + Si(8)O(2)2(OH)(2)

Cummingtonite-Grunerite asbestos (Amosite) ............................. (Mg,Fe)(7)Si(8)O(2)2(OH)(2)

Tremolite-Actinolite asbestos ............................. Ca(2)(Mg,Fe)(5)Si(8)O(2)2(OH)(2)

Anthophyllite asbestos ............................. (Mg,Fe)(7)Si(8)O(2)2(OH)(2)

Asbestos Fiber: A fiber of asbestos meeting the criteria for a fiber. (See section 3.5. of this Appendix) Aspect Ratio: The ratio of the length of a fiber to its diameter usually defined as "length : width", e.g. 3:1.

Brucite: A sheet mineral with the composition Mg(OH)(2). Central Stop Dispersion Staining (microscope): This is a dark field microscope technique that images particles using only light refracted by the particle, excluding light that travels through the particle unrefracted. This is usually accomplished with a McCrone objective or other arrangement which places a circular stop with apparent aperture equal to the objective aperture in the back focal plane of the microscope.

Cleavage Fragments: Mineral particles formed by the comminution of minerals, especially those characterized by relatively parallel sides and moderate aspect ratio.

Differential Counting: The term applied to the practice of excluding certain kinds of fibers from a phase contrast asbestos count because they are not asbestos.

Fiber: A particle longer than or equal to 5 um with a length to width ratio greater than or equal to 3:1. This may include cleavage fragments. (see section 3.5 of this appendix).

Phase Contrast: Contrast obtained in the microscope by causing light scattered by small particles to destructively interfere with unscattered light, thereby enhancing the visibility of very small particles and particles with very low intrinsic contrast.

Phase Contrast Microscope: A microscope configured with a phase mask pair to create phase contrast. The technique which uses this is called Phase Contrast Microscopy (PCM).

Phase-Polar Analysis: This is the use of polarized light in a phase contrast microscope. It is used to see the same size fibers that are visible in air filter analysis. Although fibers finer than 1 um are visible, analysis of these is inferred from analysis of larger bundles that are usually present.

Phase-Polar Microscope: The phase-polar microscope is a phase contrast microscope which has an analyzer, a polarizer, a first order red plate and a rotating phase condenser all in place so that the polarized light image is enhanced by phase contrast.

Sealing Encapsulant: This is a product which can be applied, preferably by spraying, onto an asbestos surface which will seal the surface so that fibers cannot be released.

Serpentine: A mineral family consisting of minerals with the general composition Mg(3)(Si(2)O(5)(OH)(4) having the magnesium in brucite layer over a silicate layer. Minerals important in asbestos analysis included in this family are chrysotile, lizardite, antigorite.

1.1. History

Light microscopy has been used for well over 100 years for the determination of mineral species. This analysis is carried out using specialized polarizing microscopes as well as bright field microscopes. The identification of minerals is an on-going process with many new minerals described each year. The first recorded use of asbestos was in Finland about 2500 B.C. where the material was used in the mud wattle for the wooden huts the people lived in as well as strengthening for pottery. Adverse health aspects of the mineral were noted nearly 2000 years ago when Pliny the Younger wrote about the poor health of slaves in the asbestos mines. Although known to be injurious for centuries, the first modern references to its toxicity were by the British Labor Inspectorate when it banned asbestos dust from the workplace in 1898. Asbestosis cases were described in the literature after the turn of the century. Cancer was first suspected in the mid 1930's and a causal link to mesothelioma was made in 1965. Because of the public concern for worker and public safety with the use of this material, several different types of analysis were applied to the determination of asbestos content. Light microscopy requires a great deal of experience and craft. Attempts were made to apply less subjective methods to the analysis. X-ray diffraction was partially successful in determining the mineral types but was unable to separate out the fibrous portions from the non-fibrous portions. Also, the minimum detection limit for asbestos analysis by X-ray diffraction (XRD) is about 1%. Differential Thermal Analysis (DTA) was no more successful. These provide useful corroborating information when the presence of asbestos has been shown by microscopy; however, neither can determine the difference between fibrous and non-fibrous minerals when both habits are present. The same is true of Infrared Absorption (IR).

When electron microscopy was applied to asbestos analysis, hundreds of fibers were discovered present too small to be visible in any light microscope. There are two different types of electron microscope used for asbestos analysis: Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM). Scanning Electron Microscopy is useful in identifying minerals. The SEM can provide two of the three pieces of information required to identify fibers by electron microscopy: morphology and chemistry. The third is structure as determined by Selected Area Electron Diffraction -- SAED which is performed in the TEM. Although the resolution of the SEM is sufficient for very fine fibers to be seen, accuracy of chemical analysis that can be performed on the fibers varies with fiber diameter in fibers of less than 0.2 um diameter. The TEM is a powerful tool to identify fibers too small to be resolved by light microscopy and should be used in conjunction with this method when necessary. The TEM can provide all three pieces of information required for fiber identification. Most fibers thicker than 1 um can adequately be defined in the light microscope. The light microscope remains as the best instrument for the determination of mineral type. This is because the minerals under investigation were first described analytically with the light microscope. It is inexpensive and gives positive identification for most samples analyzed. Further, when optical techniques are inadequate, there is ample indication that alternative techniques should be used for complete identification of the sample.

1.2. Principle

Minerals consist of atoms that may be arranged in random order or in a regular arrangement. Amorphous materials have atoms in random order while crystalline materials have long range order. Many materials are transparent to light, at least for small particles or for thin sections. The properties of these materials can be investigated by the effect that the material has on light passing through it. The six asbestos minerals are all crystalline with particular properties that have been identified and cataloged. These six minerals are anisotropic. They have a regular array of atoms, but the arrangement is not the same in all directions. Each major direction of the crystal presents a different regularity. Light photons travelling in each of these main directions will encounter different electrical neighborhoods, affecting the path and time of travel. The techniques outlined in this method use the fact that light traveling through fibers or crystals in different directions will behave differently, but predictably. The behavior of the light as it travels through a crystal can be measured and compared with known or determined values to identify the mineral species. Usually, Polarized Light Microscopy (PLM) is performed with strain-free objectives on a bright-field microscope platform. This would limit the resolution of the microscope to about 0.4 um. Because OSHA requires the counting and identification of fibers visible in phase contrast, the phase contrast platform is used to visualize the fibers with the polarizing elements added into the light path. Polarized light methods cannot identify fibers finer than about 1 um in diameter even though they are visible. The finest fibers are usually identified by inference from the presence of larger, identifiable fiber bundles. When fibers are present, but not identifiable by light microscopy, use either SEM or TEM to determine the fiber identity.

1.3. Advantages and Disadvantages

The advantages of light microcopy are:

(a) Basic identification of the materials was first performed by light microscopy and gross analysis. This provides a large base of published information against which to check analysis and analytical technique.

(b) The analysis is specific to fibers. The minerals present can exist in asbestiform, fibrous, prismatic, or massive varieties all at the same time. Therefore, bulk methods of analysis such as X-ray diffraction, IR analysis, DTA, etc. are inappropriate where the material is not known to be fibrous.

(c) The analysis is quick, requires little preparation time, and can be performed on-site if a suitably equipped microscope is available.

The disadvantages are:

(a) Even using phase-polar illumination, not all the fibers present may be seen. This is a problem for very low asbestos concentrations where agglomerations or large bundles of fibers may not be present to allow identification by inference.

(b) The method requires a great degree of sophistication on the part of the microscopist. An analyst is only as useful as his mental catalog of images. Therefore, a microscopist's accuracy is enhanced by experience. The mineralogical training of the analyst is very important. It is the basis on which subjective decisions are made.

(c) The method uses only a tiny amount of material for analysis. This may lead to sampling bias and false results (high or low). This is especially true if the sample is severely inhomogeneous.

(d) Fibers may be bound in a matrix and not distinguishable as fibers so identification cannot be made.

1.4. Method Performance

1.4.1. This method can be used for determination of asbestos content from 0 to 100% asbestos. The detection limit has not been adequately determined, although for selected samples, the limit is very low, depending on the number of particles examined. For mostly homogeneous, finely divided samples, with no difficult fibrous interferences, the detection limit is below 1%. For inhomogeneous samples (most samples), the detection limit remains undefined. NIST has conducted proficiency testing of laboratories on a national scale. Although each round is reported statistically with an average, control limits, etc., the results indicate a difficulty in establishing precision especially in the low concentration range. It is suspected that there is significant bias in the low range especially near 1%. EPA tried to remedy this by requiring a mandatory point counting scheme for samples less than 10%. The point counting procedure is tedious, and may introduce significant biases of its own. It has not been incorporated into this method.

1.4.2. The precision and accuracy of the quantitation tests performed in this method are unknown. Concentrations are easier to determine in commercial products where asbestos was deliberately added because the amount is usually more than a few percent. An analyst's results can be "calibrated" against the known amounts added by the manufacturer. For geological samples, the degree of homogeneity affects the precision.

1.4.3. The performance of the method is analyst dependent. The analyst must choose carefully and not necessarily randomly the portions for analysis to assure that detection of asbestos occurs when it is present. For this reason, the analyst must have adequate training in sample preparation, and experience in the location and identification of asbestos in samples. This is usually accomplished through substantial on-the-job training as well as formal education in mineralogy and microscopy.

1.5. Interferences

Any material which is long, thin, and small enough to be viewed under the microscope can be considered an interference for asbestos. There are literally hundreds of interferences in workplaces. The techniques described in this method are normally sufficient to eliminate the interferences. An analyst's success in eliminating the interferences depends on proper training.

Asbestos minerals belong to two mineral families: the serpentines and the amphiboles. In the serpentine family, the only common fibrous mineral is chrysotile. Occasionally, the mineral antigorite occurs in a fibril habit with morphology similar to the amphiboles. The amphibole minerals consist of a score of different minerals of which only five are regulated by federal standard: amosite, crocidolite, anthophyllite asbestos, tremolite asbestos and actinolite asbestos. These are the only amphibole minerals that have been commercially exploited for their fibrous properties; however, the rest can and do occur occasionally in asbestiform habit.

In addition to the related mineral interferences, other minerals common in building material may present a problem for some microscopists: gypsum, anhydrite, brucite, quartz fibers, talc fibers or ribbons, wollastonite, perlite, attapulgite, etc. Other fibrous materials commonly present in workplaces are: fiberglass, mineral wool, ceramic wool, refractory ceramic fibers, kevlar, nomex, synthetic fibers, graphite or carbon fibers, cellulose (paper or wood) fibers, metal fibers, etc.

Matrix embedding material can sometimes be a negative The analyst may not be able to easily extract the from the matrix in order to use the method. Where possible, the matrix before the analysis, taking careful note of the loss of weight. Some common matrix materials are: vinyl, rubber, tar, paint, plant fiber, cement, and epoxy. A further negative interference is that the asbestos fibers themselves may be either too small to be seen in Phase contrast Microscopy (PCM) or of a very low fibrous quality, having the appearance of plant fibers. The analyst's ability to deal with these materials increases with experience.

1.6. Uses and Occupational Exposure

Asbestos is ubiquitous in the environment. More than 40% of the land area of the United States is composed of minerals which may contain asbestos. Fortunately, the actual formation of great amounts of asbestos is relatively rare. Nonetheless, there are locations in which environmental exposure can be severe such as in the Serpentine Hills of California.

There are thousands of uses for asbestos in industry and the home. Asbestos abatement workers are the most current segment of the population to have occupational exposure to great amounts of asbestos. If the material is undisturbed, there is no exposure. Exposure occurs when the asbestos-containing material is abraded or otherwise disturbed during maintenance operations or some other activity. Approximately 95% of the asbestos in place in the United States is chrysotile.

Amosite and crocidolite make up nearly all the difference. Tremolite and anthophyllite make up a very small percentage. Tremolite is found in extremely small amounts in certain chrysotile deposits. Actinolite exposure is probably greatest from environmental sources, but has been identified in vermiculite containing, sprayed-on insulating materials which may have been certified as asbestos-free.

1.7. Physical and Chemical Properties

The nominal chemical compositions for the asbestos minerals were given in Section 1. Compared to cleavage fragments of the same minerals, asbestiform fibers possess a high tensile strength along the fiber axis. They are chemically inert, non-combustible, and heat resistant. Except for chrysotile, they are insoluble in Hydrochloric acid (HCl). Chrysotile is slightly soluble in HCl. Asbestos has high electrical resistance and good sound absorbing characteristics. It can be woven into cables, fabrics or other textiles, or matted into papers, felts, and mats.

1.8. Toxicology (This Section is for Information Only and Should Not Be Taken as OSHA Policy)

Possible physiologic results of respiratory exposure to asbestos are mesothelioma of the pleura or peritoneum, interstitial fibrosis, asbestosis, pneumoconiosis, or respiratory cancer. The possible consequences of asbestos exposure are detailed in the NIOSH Criteria Document or in the OSHA Asbestos Standards 29 CFR 1910.1001 and 29 CFR 1926.1101.

2. Sampling Procedure

2.1. Equipment for sampling

(a) Tube or cork borer sampling device (b) Knife (c) 20 mL scintillation vial or similar vial (d) Sealing encapsulant

2.2. Safety Precautions

Asbestos is a known carcinogen. Take care when sampling. While in an asbestos-containing atmosphere, a properly selected and fit- tested respirator should be worn. Take samples in a manner to cause the least amount of dust. Follow these general guidelines:

(a) Do not make unnecessary dust. (b) Take only a small amount (1 to 2 g). (c) Tightly close the sample container. (d) Use encapsulant to seal the spot where the sample was taken, if necessary.

2.3. Sampling Procedure

Samples of any suspect material should be taken from an inconspicuous place. Where the material is to remain, seal the sampling wound with an encapsulant to eliminate the potential for exposure from the sample site. Microscopy requires only a few milligrams of material. The amount that will fill a 20 mL scintillation vial is more than adequate. Be sure to collect samples from all layers and phases of material. If possible, make separate samples of each different phase of the material. This will aid in determining the actual hazard. DO NOT USE ENVELOPES, PLASTIC OR PAPER BAGS OF ANY KIND TO COLLECT SAMPLES. The use of plastic bags presents a contamination hazard to laboratory personnel and to other samples. When these containers are opened, a bellows effect blows fibers out of the container onto everything, including the person opening the container.

If a cork-borer type sampler is available, push the tube through the material all the way, so that all layers of material are sampled. Some samplers are intended to be disposable. These should be capped and sent to the laboratory. If a non-disposable cork borer is used, empty the contents into a scintillation vial and send to the laboratory. Vigorously and completely clean the cork borer between samples.

2.4 Shipment

Samples packed in glass vials must not touch or they might break in shipment.

(a) Seal the samples with a sample seal (such as the OSHA 21) over the end to guard against tampering and to identify the sample.

(b) Package the bulk samples in separate packages from the air samples. They may cross-contaminate each other and will invalidate the results of the air samples.

(c) Include identifying paperwork with the samples, but not in contact with the suspected asbestos.

(d) To maintain sample accountability, ship the samples by certified mail, overnight express, or hand carry them to the laboratory.

3. Analysis

The analysis of asbestos samples can be divided into two major parts:

sample preparation and microscopy. Because of the different asbestos uses that may be encountered by the analyst, each sample may need different preparation steps. The choices are outlined below. There are several different tests that are performed to identify the asbestos species and determine the percentage. They will be explained below.

3.1. Safety

(a) Do not create unnecessary dust. Handle the samples in HEPA- filter equipped hoods. If samples are received in bags, envelopes or other inappropriate container, open them only in a hood having a face velocity at or greater than 100 fpm. Transfer a small amount to a scintillation vial and only handle the smaller amount.

(b) Open samples in a hood, never in the open lab area.

(c) Index of refraction oils can be toxic. Take care not to get this material on the skin. Wash immediately with soap and water if this happens.

(d) Samples that have been heated in the muffle furnace or the drying oven may be hot. Handle them with tongs until they are cool enough to handle.

(e) Some of the solvents used, such as THF (tetrahydrofuran), are toxic and should only be handled in an appropriate fume hood and according to instructions given in the Material Safety Data Sheet (MSDS).

3.2. Equipment

(a) Phase contrast microscope with 10x, 16x and 40x objectives, 10x wide-field eyepieces, G-22 Walton-Beckett graticule, Whipple disk, polarizer, analyzer and first order red or gypsum plate, 100 Watt illuminator, rotating position condenser with oversize phase rings, central stop dispersion objective, Kohler illumination and a rotating mechanical stage.

(b) Stereo microscope with reflected light illumination, transmitted light illumination, polarizer, analyzer and first order red or gypsum plate, and rotating stage.

(c) Negative pressure hood for the stereo microscope

(d) Muffle furnace capable of 600 deg.C

(e) Drying oven capable of 50 -- 150 deg.C

(f) Aluminum specimen pans (g) Tongs for handling samples in the furnace

(h) High dispersion index of refraction oils (Special for dispersion staining.) n = 1.550 n = 1.585 n = 1.590 n = 1.605 n = 1.620 n = 1.670 n = 1.680 n = 1.690

(i) A set of index of refraction oils from about n=1.350 to n=2.000 in n=0.005 increments. (Standard for Becke line analysis.)

(j) Glass slides with painted or frosted ends 1x3 inches 1mm (thick, precleaned.

(k) Cover Slips 22x22 mm, #1 1/2

(l) Paper clips or dissection needles

(m) Hand grinder

(n) Scalpel with both #10 and #11 blades

(o) 0.1 molar HCl

(p) Decalcifying solution (Baxter Scientific Products) Ethylenediaminetetraacetic Acid,

Tetrasodium............................ 0.7 g/l

Sodium Potassium Tartrate.............. 8.0 mg/liter

Hydrochloric Acid...................... 99.2 g/liter

Sodium Tartrate........................ 0.14 g/liter

(q) Tetrahydrofuran (THF)

(r) Hotplate capable of 60 deg.C

(s) Balance

(t) Hacksaw blade

(u) Ruby mortar and pestle

3.3. Sample Pre-Preparation

Sample preparation begins with pre-preparation which may include chemical reduction of the matrix, heating the sample to dryness or heating in the muffle furnace. The end result is a sample which has been reduced to a powder that is sufficiently fine to fit under the cover slip. Analyze different phases of samples separately, e.g., tile and the tile mastic should be analyzed separately as the mastic may contain asbestos while the tile may not.

(a) Wet Samples Samples with a high water content will not give the proper dispersion colors and must be dried prior to sample mounting. Remove the lid of the scintillation vial, place the bottle in the drying oven and heat at 100 deg.C to dryness (usually about 2 h). Samples which are not submitted to the lab in glass must be removed and placed in glass vials or aluminum weighing pans before placing them in the drying oven.

(b) Samples With Organic Interference -- Muffle Furnace

These may include samples with tar as a matrix, vinyl asbestos tile, or any other organic that can be reduced by heating. Remove the sample from the vial and weigh in a balance to determine the weight of the submitted portion. Place the sample in a muffle furnace at 500 deg.C for 1 to 2 h or until all obvious organic material has been removed. Retrieve, cool and weigh again to determine the weight loss on ignition. This is necessary to determine the asbestos content of the submitted sample, because the analyst will be looking at a reduced sample.

Note: Heating above 600 deg.C will cause the sample to undergo a structural change which, given sufficient time, will convert the chrysotile to forsterite. Heating even at lower temperatures for 1 to 2 h may have a measurable effect on the optical properties of the minerals. If the analyst is unsure of what to expect, a sample of standard asbestos should be heated to the same temperature for the same length of time so that it can be examined for the proper interpretation.

(c) Samples With Organic Interference -- THF

Vinyl asbestos tile is the most common material treated with this solvent, although, substances containing tar will sometimes yield to this treatment. Select a portion of the material and then grind it up if possible. Weigh the sample and place it in a test tube. Add sufficient THF to dissolve the organic matrix. This is usually about 4 to 5 mL. Remember, THF is highly flammable. Filter the remaining material through a tared silver membrane, dry and weigh to determine how much is left after the solvent extraction. Further process the sample to remove carbonate or mount directly.

(d) Samples With Carbonate Interference

Carbonate material is often found on fibers and sometimes must be removed in order to perform dispersion microscopy. Weigh out a portion of the material and place it in a test tube. Add a sufficient amount of 0.1 M HCl or decalcifying solution in the tube to react all the carbonate as evidenced by gas formation; i.e., when the gas bubbles stop, add a little more solution. If no more gas forms, the reaction is complete. Filter the material out through a tared silver membrane, dry and weigh to determine the weight lost.

3.4. Sample Preparation

Samples must be prepared so that accurate determination can be made of the asbestos type and amount present. The following steps are carried out in the low-flow hood (a low-flow hood has less than 50 fpm flow):

(1) If the sample has large lumps, is hard, or cannot be made to lie under a cover slip, the grain size must be reduced. Place a small amount between two slides and grind the material between them or grind a small amount in a clean mortar and pestle. The choice of whether to use an alumina, ruby, or diamond mortar depends on the hardness of the material. Impact damage can alter the asbestos mineral if too much mechanical shock occurs. (Freezer mills can completely destroy the observable crystallinity of asbestos and should not be used). For some samples, a portion of material can be shaved off with a scalpel, ground off with a hand grinder or hack saw blade.

The preparation tools should either be disposable or cleaned thoroughly. Use vigorous scrubbing to loosen the fibers during the washing. Rinse the implements with copious amounts of water and air- dry in a dust-free environment.

(2) If the sample is powder or has been reduced as in (1) above, it is ready to mount. Place a glass slide on a piece of optical tissue and write the identification on the painted or frosted end. Place two drops of index of refraction medium n=1.550 on the slide. (The medium n=1.550 is chosen because it is the matching index for chrysotile. Dip the end of a clean paper-clip or dissecting needle into the droplet of refraction medium on the slide to moisten it. Then dip the probe into the powder sample. Transfer what sticks on the probe to the slide. The material on the end of the probe should have a diameter of about 3 mm for a good mount. If the material is very fine, less sample may be appropriate. For non-powder samples such as fiber mats, forceps should be used to transfer a small amount of material to the slide. Stir the material in the medium on the slide, spreading it out and making the preparation as uniform as possible. Place a cover-slip on the preparation by gently lowering onto the slide and allowing it to fall "trapdoor" fashion on the preparation to push out any bubbles. Press gently on the cover slip to even out the distribution of particulate on the slide. If there is insufficient mounting oil on the slide, one or two drops may be placed near the edge of the coverslip on the slide. Capillary action will draw the necessary amount of liquid into the preparation. Remove excess oil with the point of a laboratory wiper.

Treat at least two different areas of each phase in this fashion. Choose representative areas of the sample. It may be useful to select particular areas or fibers for analysis. This is useful to identify asbestos in severely inhomogeneous samples.

When it is determined that amphiboles may be present, repeat the above process using the appropriate high-dispersion oils until an identification is made or all six asbestos minerals have been ruled out. Note that percent determination must be done in the index medium 1.550 because amphiboles tend to disappear in their matching mediums.

3.5. Analytical procedure

Note: This method presumes some knowledge of mineralogy and optical petrography.

The analysis consists of three parts: The determination of whether there is asbestos present, what type is present and the determination of how much is present. The general flow of the analysis is:

(1) Gross examination.

(2) Examination under polarized light on the stereo microscope.

(3) Examination by phase-polar illumination on the compound phase microscope.

(4) Determination of species by dispersion stain. Examination by Becke line analysis may also be used; however, this is usually more cumbersome for asbestos determination.

(5) Difficult samples may need to be analyzed by SEM or TEM, or the results from those techniques combined with light microscopy for a definitive identification.

Identification of a particle as asbestos requires that it be asbestiform. Description of particles should follow the suggestion of Campbell. (Figure 1)

 

(For Figure 1, Particle definitions showing mineral
growth habits, see paper copy)

For the purpose of regulation, the mineral must be one of the six minerals covered and must be in the asbestos growth habit. Large specimen samples of asbestos generally have the gross appearance of wood. Fibers are easily parted from it. Asbestos fibers are very long compared with their widths. The fibers have a very high tensile strength as demonstrated by bending without breaking. Asbestos fibers exist in bundles that are easily parted, show longitudinal fine structure and may be tufted at the ends showing "bundle ofsticks" morphology. In the microscope some of these properties may not be observable. Amphiboles do not always show striations along their length even when they are asbestos. Neither will they always show tufting. They generally do not show a curved nature except for very long fibers. Asbestos and asbestiform minerals are usually characterized in groups by extremely high aspect ratios (greater than 100:1). While aspect ratio analysis is useful for characterizing populations of fibers, it cannot be used to identify individual fibers of intermediate to short aspect ratio. Observation of many fibers is often necessary to determine whether a sample consists of "cleavage fragments" or of asbestos fibers.

Most cleavage fragments of the asbestos minerals are easily distinguishable from true asbestos fibers. This is because true cleavage fragments usually have larger diameters than 1 um. Internal structure of particles larger than this usually shows them to have no internal fibrillar structure. In addition, cleavage fragments of the monoclinic amphiboles show inclined extinction under crossed polars with no compensator. Asbestos fibers usually show extinction at zero degrees or ambiguous extinction if any at all. Morphologically, the larger cleavage fragments are obvious by their blunt or stepped ends showing prismatic habit. Also, they tend to be acicular rather than filiform.

Where the particles are less than 1 um in diameter and have an aspect ratio greater than or equal to 3:1, it is recommended that the sample be analyzed by SEM or TEM if there is any question whether the fibers are cleavage fragments or asbestiform particles.

Care must be taken when analyzing by electron microscopy because the interferences are different from those in light microscopy and may structurally be very similar to asbestos. The classic interference is between anthophyllite and biopyribole or intermediate fiber. Use the same morphological clues for electron microscopy as are used for light microscopy, e.g. fibril splitting, internal longitudinal striation, fraying, curvature, etc.

(1) Gross examination:

Examine the sample, preferably in the glass vial. Determine the presence of any obvious fibrous component. Estimate a percentage based on previous experience and current observation. Determine whether any pre-preparation is necessary. Determine the number of phases present. This step may be carried out or augmented by observation at 6 to 40 x under a stereo microscope.

(2) After performing any necessary pre-preparation, prepare slides of each phase as described above. Two preparations of the same phase in the same index medium can be made side-by-side on the same glass for convenience. Examine with the polarizing stereo microscope. Estimate the percentage of asbestos based on the amount of birefringent fiber present.

(3) Examine the slides on the phase-polar microscopes at magnifications of 160 and 400 x . Note the morphology of the fibers. Long, thin, very straight fibers with little curvature are indicative of fibers from the amphibole family. Curved, wavy fibers are usually indicative of chrysotile. Estimate the percentage of asbestos on the phase-polar microscope under conditions of crossed polars and a gypsum plate. Fibers smaller than 1.0 um in thickness must be identified by inference to the presence of larger, identifiable fibers and morphology. If no larger fibers are visible, electron microscopy should be performed. At this point, only a tentative identification can be made. Full identification must be made with dispersion microscopy. Details of the tests are included in the appendices.

(4) Once fibers have been determined to be present, they must be identified. Adjust the microscope for dispersion mode and observe the fibers. The microscope has a rotating stage, one polarizing element, and a system for generating dark-field dispersion microscopy (see Section 4.6. of this appendix). Align a fiber with its length parallel to the polarizer and note the color of the Becke lines. Rotate the stage to bring the fiber length perpendicular to the polarizer and note the color. Repeat this process for every fiber or fiber bundle examined. The colors must be consistent with the colors generated by standard asbestos reference materials for a positive identification. In n=1.550, amphiboles will generally show a yellow to straw-yellow color indicating that the fiber indices of refraction are higher than the liquid. If long, thin fibers are noted and the colors are yellow, prepare further slides as above in the suggested matching liquids listed below:

Type of asbestos Index of refraction
Chrysotile n = 1.550
Amosite n = 1.670 r 1.680
Crocidolite n = 1.690
Anthophyllite n = 1.605 nd 1.620
Tremolite n = 1.605 and 1.620
Actinolite n = 1.620

Where more than one liquid is suggested, the first is preferred; however, in some cases this liquid will not give good dispersion color. Take care to avoid interferences in the other liquid; e.g., wollastonite in n=1.620 will give the same colors as tremolite. In n=1.605 wollastonite will appear yellow in all directions. Wollastonite may be determined under crossed polars as it will change from blue to yellow as it is rotated along its fiber axis by tapping on the cover slip. Asbestos minerals will not change in this way.

Determination of the angle of extinction may, when present, aid in the determination of anthophyllite from tremolite. True asbestos fibers usually have 0 deg. extinction or ambiguous extinction, while cleavage fragments have more definite extinction.

Continue analysis until both preparations have been examined and all present species of asbestos are identified. If there are no fibers present, or there is less than 0.1% present, end the analysis with the minimum number of slides (2).

(5) Some fibers have a coating on them which makes dispersion microscopy very difficult or impossible. Becke line analysis or electron microscopy may be performed in those cases. Determine the percentage by light microscopy. TEM analysis tends to overestimate the actual percentage present.

(6) Percentage determination is an estimate of occluded area, tempered by gross observation. Gross observation information is used to make sure that the high magnification microscopy does not greatly over- or under- estimate the amount of fiber present. This part of the analysis requires a great deal of experience. Satisfactory models for asbestos content analysis have not yet been developed, although some models based on metallurgical grain-size determination have found some utility. Estimation is more easily handled in situations where the grain sizes visible at about 160 x are about the same and the sample is relatively homogeneous.

View all of the area under the cover slip to make the percentage determination. View the fields while moving the stage, paying attention to the clumps of material. These are not usually the best areas to perform dispersion microscopy because of the interference from other materials. But, they are the areas most likely to represent the accurate percentage in the sample. Small amounts of asbestos require slower scanning and more frequent analysis of individual fields.

Report the area occluded by asbestos as the concentration. This estimate does not generally take into consideration the difference in density of the different species present in the sample. For most samples this is adequate. Simulation studies with similar materials must be carried out to apply microvisual estimation for that purpose and is beyond the scope of this procedure.

(7) Where successive concentrations have been made by chemical or physical means, the amount reported is the percentage of the material in the "as submitted" or original state. The percentage determined by microscopy is multiplied by the fractions remaining after pre-preparation steps to give the percentage in the original sample. For example:

Step 1. 60% remains after heating at 550 deg.C for 1 h. Step 2. 30% of the residue of step 1 remains after dissolution of carbonate in 0.1 m HCl.

Step 3. Microvisual estimation determines that 5% of the sample is chrysotile asbestos.

 

  • The reported result is:

 

R = (Microvisual result in percent)x(Fraction remaining after step 2) x(Fraction remaining of original sample after step 1)
R = (5) x (.30) x (.60) = 0.9%

(8) Report the percent and type of asbestos present. For samples where asbestos was identified, but is less than 1.0%, report "Asbestos present, less than 1.0%." There must have been at least two observed fibers or fiber bundles in the two preparations to be reported as present. For samples where asbestos was not seen, report as "None Detected."

Auxiliary Information

Because of the subjective nature of asbestos analysis, certain concepts and procedures need to be discussed in more depth. This information will help the analyst understand why some of the procedures are carried out the way they are.

4.1. Light

Light is electromagnetic energy. It travels from its source in packets called quanta. It is instructive to consider light as a plane wave. The light has a direction of travel. Perpendicular to this and mutually perpendicular to each other, are two vector components. One is the magnetic vector and the other is the electric vector. We shall only be concerned with the electric vector. In this description, the interaction of the vector and the mineral will describe all the observable phenomena. From a light source such a microscope illuminator, light travels in all different direction from the filament.

In any given direction away from the filament, the electric vector is perpendicular to the direction of travel of a light ray. While perpendicular, its orientation is random about the travel axis. If the electric vectors from all the light rays were lined up by passing the light through a filter that would only let light rays with electric vectors oriented in one direction pass, the light would then be POLARIZED.

Polarized light interacts with matter in the direction of the electric vector. This is the polarization direction. Using this property it is possible to use polarized light to probe different materials and identify them by how they interact with light.

The speed of light in a vacuum is a constant at about 2.99 x 10(8) m/s. When light travels in different materials such as air, water, minerals or oil, it does not travel at this speed. It travels slower. This slowing is a function of both the material through which the light is traveling and the wavelength or frequency of the light. In general, the more dense the material, the slower the light travels. Also, generally, the higher the frequency, the slower the light will travel. The ratio of the speed of light in a vacuum to that in a material is called the index of refraction (n). It is usually measured at 589 nm (the sodium D line). If white light (light containing all the visible wavelengths) travels through a material, rays of longer wavelengths will travel faster than those of shorter wavelengths, this separation is called dispersion. Dispersion is used as an identifier of materials as described in Section 4.6.

4.2. Material Properties

Materials are either amorphous or crystalline. The difference between these two descriptions depends on the positions of the atoms in them. The atoms in amorphous materials are randomly arranged with no long range order. An example of an amorphous material is glass. The atoms in crystalline materials, on the other hand, are in regular arrays and have long range order. Most of the atoms can be found in highly predictable locations. Examples of crystalline material are salt, gold, and the asbestos minerals.

It is beyond the scope of this method to describe the different types of crystalline materials that can be found, or the full description of the classes into which they can fall. However, some general crystallography is provided below to give a foundation to the procedures described.

With the exception of anthophyllite, all the asbestos minerals belong to the monoclinic crystal type. The unit cell is the basic repeating unit of the crystal and for monoclinic crystals can be described as having three unequal sides, two 90 deg. angles and one angle not equal to 90 deg.. The orthorhombic group, of which anthophyllite is a member has three unequal sides and three 90 deg. angles. The unequal sides are a consequence of the complexity of fitting the different atoms into the unit cell. Although the atoms are in a regular array, that array is not symmetrical in all directions. There is long range order in the three major directions of the crystal. However, the order is different in each of the three directions. This has the effect that the index of refraction is different in each of the three directions. Using polarized light, we can investigate the index of refraction in each of the directions and identify the mineral or material under investigation. The indices alpha, beta, and gamma are used to identify the lowest, middle, and highest index of refraction respectively. The x direction, associated with alpha is called the fast axis. Conversely, the z direction is associated with gamma and is the slow direction. Crocidolite has alpha along the fiber length making it "length-fast". The remainder of the asbestos minerals have the gamma axis along the fiber length. They are called "length-slow". This orientation to fiber length is used to aid in the identification of asbestos.

4.3. Polarized Light Technique

Polarized light microscopy as described in this section uses the phase-polar microscope described in Section 3.2. A phase contrast microscope is fitted with two polarizing elements, one below and one above the sample. The polarizers have their polarization directions at right angles to each other. Depending on the tests performed, there may be a compensator between these two polarizing elements. A compensator is a piece of mineral with known properties that "compensates" for some deficiency in the optical train. Light emerging from a polarizing element has its electric vector pointing in the polarization direction of the element. The light will not be subsequently transmitted through a second element set at a right angle to the first element. Unless the light is altered as it passes from one element to the other, there is no transmission of light.

4.4. Angle of Extinction

Crystals which have different crystal regularity in two or three main directions are said to be anisotropic. They have a different index of refraction in each of the main directions. When such a crystal is inserted between the crossed polars, the field of view is no longer dark but shows the crystal in color. The color depends on the properties of the crystal. The light acts as if it travels through the crystal along the optical axes. If a crystal optical axis were lined up along one of the polarizing directions (either the polarizer or the analyzer) the light would appear to travel only in that direction, and it would blink out or go dark. The difference in degrees between the fiber direction and the angle at which it blinks out is called the angle of extinction. When this angle can be measured, it is useful in identifying the mineral. The procedure for measuring the angle of extinction is to first identify the polarization direction in the microscope. A commercial alignment slide can be used to establish the polarization directions or use anthophyllite or another suitable mineral. This mineral has a zero degree angle of extinction and will go dark to extinction as it aligns with the polarization directions. When a fiber of anthophyllite has gone to extinction, align the eyepiece reticle or graticule with the fiber so that there is a visual cue as to the direction of polarization in the field of view. Tape or otherwise secure the eyepiece in this position so it will not shift.

After the polarization direction has been identified in the field of view, move the particle of interest to the center of the field of view and align it with the polarization direction. For fibers, align the fiber along this direction. Note the angular reading of the rotating stage. Looking at the particle, rotate the stage until the fiber goes dark or "blinks out". Again note the reading of the stage. The difference in the first reading and the second is an angle of extinction.

The angle measured may vary as the orientation of the fiber changes about its long axis. Tables of mineralogical data usually report the maximum angle of extinction. Asbestos forming minerals, when they exhibit an angle of extinction, usually do show an angle of extinction close to the reported maximum, or as appropriate depending on the substitution chemistry.

4.5. Crossed Polars with Compensator

When the optical axes of a crystal are not lined up along one of the polarizing directions (either the polarizer or the analyzer) part of the light travels along one axis and part travels along the other visible axis. This is characteristic of birefringent materials.

The color depends on the difference of the two visible indices of refraction and the thickness of the crystal. The maximum difference available is the difference between the alpha and the gamma axes. This maximum difference is usually tabulated as the birefringence of the crystal.

For this test, align the fiber at 45 deg. to the polarization directions in order to maximize the contribution to each of the optical axes. The colors seen are called retardation colors. They arise from the recombination of light which has traveled through the two separate directions of the crystal. One of the rays is retarded behind the other since the light in that direction travels slower. On recombination, some of the colors which make up white light are enhanced by constructive interference and some are suppressed by destructive interference. The result is a color dependent on the difference between the indices and the thickness of the crystal. The proper colors, thicknesses, and retardations are shown on a Michel- Levy chart. The three items, retardation, thickness and birefringence are related by the following relationship:

R = t(n gamma - n alpha) R = retardation, t = crystal thickness in um, and n alpha, gamma = indices of refraction.

Examination of the equation for asbestos minerals reveals that the visible colors for almost all common asbestos minerals and fiber sizes are shades of gray and black. The eye is relatively poor at discriminating different shades of gray. It is very good at discriminating different colors. In order to compensate for the low retardation, a compensator is added to the light train between the polarization elements. The compensator used for this test is a gypsum plate of known thickness and birefringence. Such a compensator when oriented at 45 deg. to the polarizer direction, provides a retardation of 530 nm of the 530 nm wavelength color. This enhances the red color and gives the background a characteristic red to red-magenta color. If this "full-wave" compensator is in place when the asbestos preparation is inserted into the light train, the colors seen on the fibers are quite different. Gypsum, like asbestos has a fast axis and a slow axis. When a fiber is aligned with its fast axis in the same direction as the fast axis of the gypsum plate, the ray vibrating in the slow direction is retarded by both the asbestos and the gypsum. This results in a higher retardation than would be present for either of the two minerals. The color seen is a second order blue. When the fiber is rotated 90 deg. using the rotating stage, the slow direction of the fiber is now aligned with the fast direction of the gypsum and the fast direction of the fiber is aligned with the slow direction of the gypsum. Thus, one ray vibrates faster in the fast direction of the gypsum, and slower in the slow direction of the fiber; the other ray will vibrate slower in the slow direction of the gypsum and faster in the fast direction of the fiber. In this case, the effect is subtractive and the color seen is a first order yellow. As long as the fiber thickness does not add appreciably to the color, the same basic colors will be seen for all asbestos types except crocidolite. In crocidolite the colors will be weaker, may be in the opposite directions, and will be altered by the blue absorption color natural to crocidolite. Hundreds of other materials will give the same colors as asbestos, and therefore, this test is not definitive for asbestos. The test is useful in discriminating against fiberglass or other amorphous fibers such as some synthetic fibers. Certain synthetic fibers will show retardation colors different than asbestos; however, there are some forms of polyethylene and aramid which will show morphology and retardation colors similar to asbestos minerals. This test must be supplemented with a positive identification test when birefringent fibers are present which can not be excluded by morphology. This test is relatively ineffective for use on fibers less than 1 um in diameter. For positive confirmation TEM or SEM should be used if no larger bundles or fibers are visible.

4.6. Dispersion Staining

Dispersion microscopy or dispersion staining is the method of choice for the identification of asbestos in bulk materials. Becke line analysis is used by some laboratories and yields the same results as does dispersion staining for asbestos and can be used in lieu of dispersion staining. Dispersion staining is performed on the same platform as the phase-polar analysis with the analyzer and compensator removed. One polarizing element remains to define the direction of the light so that the different indices of refraction of the fibers may be separately determined. Dispersion microscopy is a dark-field technique when used for asbestos. Particles are imaged with scattered light. Light which is unscattered is blocked from reaching the eye either by the back field image mask in a McCrone objective or a back field image mask in the phase condenser. The most convenient method is to use the rotating phase condenser to move an oversized phase ring into place. The ideal size for this ring is for the central disk to be just larger than the objective entry aperture as viewed in the back focal plane. The larger the disk, the less scattered light reaches the eye. This will have the effect of diminishing the intensity of dispersion color and will shift the actual color seen. The colors seen vary even on microscopes from the same manufacturer. This is due to the different bands of wavelength exclusion by different mask sizes. The mask may either reside in the condenser or in the objective back focal plane. It is imperative that the analyst determine by experimentation with asbestos standards what the appropriate colors should be for each asbestos type. The colors depend also on the temperature of the preparation and the exact chemistry of the asbestos. Therefore, some slight differences from the standards should be allowed. This is not a serious problem for commercial asbestos uses. This technique is used for identification of the indices of refraction for fibers by recognition of color. There is no direct numerical readout of the index of refraction. Correlation of color to actual index of refraction is possible by referral to published conversion tables. This is not necessary for the analysis of asbestos. Recognition of appropriate colors along with the proper morphology are deemed sufficient to identify the commercial asbestos minerals. Other techniques including SEM, TEM, and XRD may be required to provide additional information in order to identify other types of asbestos.

Make a preparation in the suspected matching high dispersion oil, e.g., n=1.550 for chrysotile. Perform the preliminary tests to determine whether the fibers are birefringent or not. Take note of the morphological character. Wavy fibers are indicative of chrysotile while long, straight, thin, frayed fibers are indicative of amphibole asbestos. This can aid in the selection of the appropriate matching oil. The microscope is set up and the polarization direction is noted as in Section 4.4. Align a fiber with the polarization direction. Note the color. This is the color parallel to the polarizer. Then rotate the fiber rotating the stage 90 deg. so that the polarization direction is across the fiber. This is the perpendicular position. Again note the color. Both colors must be consistent with standard asbestos minerals in the correct direction for a positive identification of asbestos. If only one of the colors is correct while the other is not, the identification is not positive. If the colors in both directions are bluish-white, the analyst has chosen a matching index oil which is higher than the correct matching oil, e.g. the analyst has used n=1.620 where chrysotile is present. The next lower oil (Section 3.5.) should be used to prepare another specimen. If the color in both directions is yellow-white to straw-yellow-white, this indicates that the index of the oil is lower than the index of the fiber, e.g. the preparation is in n=1.550 while anthophyllite is present. Select the next higher oil (Section 3.5.) and prepare another slide. Continue in this fashion until a positive identification of all asbestos species present has been made or all possible asbestos species have been ruled out by negative results in this test. Certain plant fibers can have similar dispersion colors as asbestos. Take care to note and evaluate the morphology of the fibers or remove the plant fibers in pre-preparation. Coating material on the fibers such as carbonate or vinyl may destroy the dispersion color. Usually, there will be some outcropping of fiber which will show the colors sufficient for identification. When this is not the case, treat the sample as described in Section 3.3. and then perform dispersion staining. Some samples will yield to Becke line analysis if they are coated or electron microscopy can be used for identification.

5. References

5.1. Crane, D.T., Asbestos in Air, OSHA method ID160, Revised November 1992.

5.2. Ford, W.E., Dana's Textbook of Mineralogy; Fourth Ed.; John Wiley and Son, New York, 1950, p. vii.

5.3. Selikoff, I.J., Lee, D.H.K., Asbestos and Disease, Academic Press, New York, 1978, pp. 3,20.

5.4. Women Inspectors of Factories. Annual Report for 1898, H.M. Statistical Office, London, p. 170 (1898).

5.5. Selikoff,.I.J., Lee, D.H.K., Asbestos and Disease, Academic Press, New York, 1978, pp. 26,30.

5.6. Campbell, W.J., et al, Selected Silicate Minerals and Their Asbestiform Varieties, United States Department of the Interior, Bureau of Mines, Information Circular 8751, 1977.

5.7. Asbestos, Code of Federal Regulations, 29 CFR 1910.1001 and 29 CFR 1926.58.

5.8. National Emission Standards for Hazardous Air Pollutants; Asbestos NESHAP Revision, Federal Register, Vol. 55, No. 224, 20 November 1990, p. 48410.

5.9. Ross, M. The Asbestos Minerals: Definitions, Description, Modes of Formation, Physical and Chemical Properties and Health Risk to the Mining Community, Nation Bureau of Standards Special Publication, Washington, D.C., 1977.

5.10. Lilis, R., Fibrous Zeolites and Endemic Mesothelioma in Cappadocia, Turkey, J. Occ Medicine, 1981, 23,(8),548-550.

5.11. Occupational Exposure to Asbestos -- 1972, U.S. Department of Health Education and Welfare, Public Health Service, Center for Disease Control, National Institute for Occupational Safety and Health, HSM-72-10267.

5.12. Campbell,W.J., et al, Relationship of Mineral Habit to Size Characteristics for Tremolite Fragments and Fibers, United States Department of the Interior, Bureau of Mines, Information Circular 8367, 1979.

5.13. Mefford, D., DCM Laboratory, Denver, private communication, July 1987.

5.14. Deer, W.A., Howie, R.A., Zussman, J., Rock Forming Minerals, Longman, Thetford, UK, 1974.

5.15. Kerr, P.F., Optical Mineralogy; Third Ed. McGraw-Hill, New York, 1959.

5.16. Veblen, D.R. (Ed.), Amphiboles and Other Hydrous Pyriboles -- Mineralogy, Reviews in Mineralogy, Vol 9A, Michigan, 1982, pp 1-102.

5.17. Dixon, W.C., Applications of Optical Microscopy in the Analysis of Asbestos and Quartz, ACS Symposium Series, No. 120, Analytical Techniques in Occupational Health Chemistry, 1979.

5.18. Polarized Light Microscopy, McCrone Research Institute, Chicago, 1976.

5.19. Asbestos Identification, McCrone Research Institute, G&G printers, Chicago, 1987.

5.20. McCrone, W.C., Calculation of Refractive Indices from Dispersion Staining Data, The Microscope, No 37, Chicago, 1989.

5.21. Levadie, B. (Ed.), Asbestos and Other Health Related Silicates, ASTM Technical Publication 834, ASTM, Philadelphia 1982.

5.22. Steel, E. and Wylie, A., Riordan, P.H. (Ed.), Mineralogical Characteristics of Asbestos, Geology of Asbestos Deposits, pp. 93-101, SME-AIME, 1981.

5.23. Zussman, J., The Mineralogy of Asbestos, Asbestos: Properties, Applications and Hazards, pp. 45-67 Wiley, 1979.

[FR Doc. 94-18863 Filed 8-8-94; 8:45 am]