Regulatory Review of OSHA'S Ethylene Oxide Standard [29 CFR 1910.1047]

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Printing Instructions

REGULATORY REVIEW OF THE
OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION'S
ETHYLENE OXIDE STANDARD
[29 CFR 1910.1047]

PURSUANT TO SECTION 610 OF THE REGULATORY FLEXIBILITY ACT
AND
SECTION 5 OF EXECUTIVE ORDER 12866

Office of Evaluations and Audit Analysis
Directorate of Evaluation and Analysis
Occupational Safety and Health Administration
200 Constitution Ave., N.W.
Washington, D.C. 20210

March 2005

REGULATORY REVIEW OF OSHA'S ETHYLENE OXIDE STANDARD
[29 CFR 1910.1047]

EXECUTIVE SUMMARY

This report presents the conclusions of OSHA's regulatory review of the Ethylene Oxide Standard under the requirements of both Sections 610 of the Regulatory Flexibility Act and Section 5 of Executive Order (EO) 12866. Under Section 610, this review examines whether the standard should be continued without change, rescinded, or amended to minimize any significant impact on a substantial number of small entities. OSHA has considered the continued need for the rule, comments and complaints received, complexity of the rule, whether the rule is duplicative and changes since its issuance. Under Section 5 of EO 12866, this review examines whether the standard has become unjustified or unnecessary as a result of changed circumstances, and whether the standard is compatible with other regulations or is duplicative or inappropriately burdensome in the aggregate. This review also ensures that the regulation is consistent with the priorities and the principles set forth in EO 12866 and within applicable law, and examines whether the effectiveness of the standard can be improved. In order to assist OSHA in this review, OSHA requested public comments on these issues and held a public meeting (62 FR 28649, May 27, 1997).

The Section 610 Review of the EtO Standard indicates that:

There is a continued need for the rule. Workers exposed to EtO in a range of industries continue to be at risk of cancer, genetic changes, reproductive effects, neurotoxicity, and sensitization. As part of this "Lookback" review, OSHA examined evidence submitted by commenters and from the scientific literature as it pertained to the findings of the 1984 risk assessment used to support the EtO Standard. Since the risk assessment was developed, the International Agency for Research on Cancer reclassified EtO as a known human carcinogen and the National Toxicology program reclassified EtO as one "known to be a human carcinogen." Based on the significant scientific information, OSHA finds that the potential carcinogenicity of EtO and the risk posed to workers continues to justify the need for the Standard. Comprehensive studies, compliance information, and public comments indicate that the Standard has been effective in reducing exposure to EtO thereby achieving the predicted health benefits. The public comments evidenced widespread support for continuance of the EtO Standard and endorsed its effectiveness. No commenter argued that the standard should be rescinded.
The evidence indicates that the EtO Standard has not had a negative economic impact on the industries affected by the standard, generally, or on small businesses in those industries. Most of the small businesses affected by the EtO Standard are hospitals, medical device manufacturers, and spice manufacturers. There are no indications that the regulation of occupational exposure to EtO has impaired the economic well being of businesses in any of these sectors or has disproportionately affected small businesses.
The rule is not unduly or unreasonably complex. Although most commenters did not directly address the issue of whether the standard was considered to be unduly or unreasonably complex, a number of comments at the public meeting and submitted to the Docket requested clarification of the requirements of the standard. Difficulty in understanding or interpreting some requirements of the standard was reported in the hospital sector, which contains the majority of affected small entities. OSHA intends to issue compliance assistance and outreach materials to aid employers' understanding of the standard.
The EtO Standard does not overlap with other regulations. Four major federal regulatory entities in addition to OSHA currently regulate various aspects of EtO use and transport. The only potential regulatory conflict raised by one commenter during this Lookback review involved an Environmental Protection Agency standard under the Clean Air Act for EtO-using commercial sterilization and fumigation operations. Commercial sterilization and fumigation operations using one ton or more of EtO per year are required to use emission control technology to comply with EPA standards. The two agencies' rules do not actually conflict and no employers have stated that they have not been able to comply with both.
Technological improvements have improved worker safety. OSHA's independent research, comments received, and the technical literature indicate that significant technological developments have occurred since the promulgation of the standard. Improvements in sterilizer technology, the growth in number and use of alternative sterilants and sterilizing processes, and use of contract sterilizers to perform EtO sterilization have contributed to an observed reduction in occupational exposure to EtO. None of the comments received by OSHA indicated that technological feasibility problems prevented affected businesses from complying with the EtO standard.
The standard encouraged the development of improved sterilizers, which achieved compliance with the standard and cost less than other sterilizers. The newer equipment costs about half the cost of the older equipment with add-on controls. This reduced costs for all employers including small businesses.
A 1995 Congressional Office of Technology Assessment study completed after the standard took effect concluded that the Feasibility Study, which OSHA performed before issuance of the standard, was accurate and well done.

An Executive Order 12866 review of the Standard indicates that:

The EtO Standard remains both justified and necessary. As discussed in OSHA's Section 610 analysis, EtO poses significant health and safety risks to workers exposed to the substance. While the standard has resulted in dramatic reductions in occupational exposures to EtO, OSHA continues to document overexposures and non-compliance in the workplace. A study of Massachusetts hospitals demonstrated that enforcement actions were necessary before they came into compliance with the standard.
The EtO Standard is compatible with other OSHA standards and is not inappropriately burdensome in the aggregate. No public comment questioned the compatibility of the EtO standard with any OSHA or state standard.
The EtO Standard is compatible with E.O. 12866. The Executive Order essentially espouses a regulatory system that efficiently and effectively protects health and safety without imposing unacceptable or unreasonable costs on society. The regulations that are produced must be consistent, sensible, and understandable. The Lookback review has amassed numerous comments supporting the standard's effectiveness in reducing occupational exposures to EtO. In addition, the industries that use EtO appear to be familiar with the standard and have adopted improved technology, use of substitutes, and other methods to improve efficiency. No evidence was submitted to the Docket or identified by OSHA in the course of this Lookback review to suggest that the standard was imposing either a significant impact on a substantial number of small entities or that it was causing an excessive compliance burden.
The EtO Standard is effective in achieving its mission. Uniform support for retaining the EtO standard is in the public record for this Lookback review.

Conclusions and Recommendations

Based on analyses performed for this Lookback review, OSHA concludes that the EtO Standard should be continued without change and does not need to be revised or rescinded to minimize economic impacts on small entities. OSHA's original conclusions concerning the health risks of exposure to EtO have been supported by new epidemiological and health risk studies released since the promulgation of the standard in 1984. Based on exposure monitoring data from several sources indicating that occupational exposure to EtO has fallen markedly since the EtO standard went into effect, workers are being protected. OSHA enforcement program data documenting that overexposures and accidental releases of EtO continue to occur at workplaces that are not in compliance with the standard underscore the continuing need for the standard. Both employer and employee representatives indicate a continued need for the standard. OSHA has therefore concluded that the EtO Standard continues to be needed to protect workers health and safety. Accordingly, OSHA finds that there is no need at this time to modify the rule through a rulemaking process to make it more effective or less burdensome.

As a result of this Lookback review and the comments received from participants in the process, OSHA is considering enhancing the following compliance assistance materials to assist the regulated community in complying with the standard:

Enhancing compliance assistance materials clarifying and explaining the exposure monitoring requirements of the standard, particularly as these relate to the standard's emergency alert requirements and to operations potentially involving overexposures to the excursion limit.
Enhancing compliance assistance materials explaining the standard's medical surveillance requirements, particularly as these relate to the taking of occupational histories and the standard's triggers for medical surveillance.
Reviewing OSHA's existing compliance interpretations as these relate to tank changing operations and the use of respiratory protection in these operations, and developing new materials addressing these topics if necessary.
Making more widely available the 2000 NIOSH Hazard Alert entitled "Preventing Worker Injuries and Deaths from Explosions in Industrial Ethylene Oxide Sterilizer Facilities" to address the risk of explosions.

TABLE OF CONTENTS

EXECUTIVE SUMMARY

CHAPTER I

CHAPTER II

Overview
Industry Profile
Employer Compliance Experience With the Standard
Conclusions

CHAPTER III

Overview
Information on Adverse Health Effects and Quantitative Risk Assessment
New Health Information Available Since the 1984 Standard
IARC and NTP Classifications of EtO as a Known Human Carcinogen
OtheR New Information Relating to Carcinogenicity
Exposure Trends Indicate that the Standard is Effective
Accidental EtO Releases in Hospitals and Other Health Care Service Establishments
Employers and Employees Support Continuance of the Standard
Summary
References for the Health Effects and Risk Assessment Section

CHAPTER IV

Overview
Summary of Docket Comments

CHAPTER V

Overview
Existing Technology and Changes in Technological Conditions
Industries that Use EtO as a Sterilant or Fumigant
EtO Production, Usage, and Substitution Trends
Economic Changes

CHAPTER VI

Industrial Sectors Containing Affected Small Entities
Public Comments Addressing Small Entities
Impacts on Affected Small Entities
Conclusion

CHAPTER VII

Findings
OSHA's Responses to Concerns Raised by Stakeholders
Findings Concerning Specific Public Comments and Complaints
Findings Concerning Complexity of the Standard
Findings Concerning Duplication, Conflict or Overlap
Findings Concerning Changes in Technological and Economic Conditions
Outcome of the Executive Order 12866 Review
Outreach and Compliance Assistance Activities OSHA is Considering in Response to this Lookback Review

Appendix A

LIST OF TABLES

Table II-1	Number of American Hospital Association Registered Hospitals and Total Number of Beds By Type of Ownership and Type of Hospital 1980 and 1995
Table II-2	Distribution of Community Hospitals by Bed Size Category
Table II-3	Number of Commercial Sterilization Facilities Using Ethylene Oxide
Table II-4	Top Five Most Frequently Cited EtO Standard Provisions, By Size-Class of Firm Inspected, Using Citation Data from 1985-1997
Table III-1	EtO Exposure Monitoring Data from All Industries Collected by OSHA Before and After Issuance of the Final Ethylene Oxide Standard
Table III-2	EtO Exposure Monitoring Data Collected by OSHA Before and After Issuance of the Ethylene Oxide Standard, by Establishment Size
Table III-3	EtO Personal Exposure Monitoring Results from Hospital Studies
Table III-4	EtO Exposure Monitoring Data from Hospitals and Other Health Care Service Establishments Collected by OSHA Before and After Issuance of the EtO Standard
Table III-5	EtO Exposure Monitoring Data from the Medical and Pharmaceutical Products Sterilizing Industries Collected by OSHA Before and After Issuance of the EtO Standard
Table V-1	Advantages and Disadvantages of Different Methods of Sterilization (As Alternatives to EtO Sterilization)

ACKNOWLEDGEMENTS

OSHA wishes to thank those on its staff who helped with this project, especially John Martonik, Joanna Dizikes Friedrich, Marthe Kent, Chuck Gordon, and Kathy Condit.

CHAPTER I
INTRODUCTION

The Occupational Safety and Health Administration (OSHA) has conducted a review of its Ethylene Oxide (EtO) Standard under Section 610 of the Regulatory Flexibility Act¹ and Section 5 of Executive Order (EO) 12866 on Regulatory Planning and Review.

The purpose of a review under Section 610 of the Regulatory Flexibility Act:

"(S)hall be to determine whether such rule should be continued without change, or should be rescinded, or amended consistent with the stated objectives of applicable statutes to minimize any significant impact of the rules on a substantial number of small entities." "The Agency shall consider the following factors:

The continued need for the rule;
The nature of complaints or comments received concerning the rule from the public;
The complexity of the rule;
The extent to which the rule overlaps, duplicates or conflicts with other Federal rules, and, to the extent feasible, with State and local governmental rules; and
The length of time since the rule has been evaluated or the degree to which technology, economic conditions, or other factors have changed in the area affected by the rule."

The review requirements of Section 5 of EO 12866 require agencies:

"To reduce the regulatory burden on the American people, their families, their communities, their State, local, and tribal governments, and their industries; to determine whether regulations promulgated by the [Agency] have become unjustified or unnecessary as a result of changed circumstances; to confirm that regulations are both compatible with each other and not duplicative or inappropriately burdensome in the aggregate; to ensure that all regulations are consistent with the President's priorities and the principles set forth in this Executive Order, within applicable law; and to otherwise improve the effectiveness of existing regulations." To carry out these reviews, OSHA asked the public for comments on all issues raised by these provisions (62 FR 28649). Specifically, OSHA requested comments on: the impacts of the rule on small businesses; the benefits and utility of the rule in its current form and, if amended, in its amended form; the continued need for the rule; the complexity of the rule; and whether, and to what extent, the rule overlaps, duplicates, or conflicts with other Federal, State, and local government rules. OSHA also asked for comments on new developments in technology, economic conditions, or other factors affecting the ability of covered firms to comply with the EtO Standard. Furthermore, OSHA asked for comments on alternatives to the rule that would minimize significant impacts on small businesses, while achieving the objectives of the Occupational Safety and Health Act.

All documents and comments received relevant to the review, transcripts of the meeting, and documents discussed in this report are available at the OSHA Docket Office, Docket No. H-200C, Room N-3625, U.S. Department of Labor, 200 Constitution Avenue, N.W., Washington, DC 20210, Telephone (202) 693-2350.

CHAPTER II
REGULATORY ENVIRONMENT SURROUNDING THE STANDARD

OVERVIEW

In conducting this Lookback review of the Ethylene Oxide (EtO) standard under Section 610 of the Regulatory Flexibility Act and Section 5 of Executive Order 12866, OSHA developed updated estimates of the number of affected employers and employees currently covered by the standard and examined the compliance experience of affected employers. This chapter presents a profile of the affected employers by industry grouping; analyzes recent OSHA enforcement and consultation program data; presents field and State-plan State enforcement officials' perspectives on key EtO-related compliance issues; and describes information on industry compliance obtained from a review of the occupational safety and health literature and other relevant studies. Thus, this chapter provides a description of the regulatory environment in which the standard is currently being implemented.

INDUSTRY PROFILE

The EtO standard applies to all occupational exposures to ethylene oxide occurring in facilities covered by the OSH Act. The standard covers general industry employment under §1910.1047, shipyard employment under §1915.1047, construction employment under §1926.1147, and marine terminal and longshoring operations under §§1917.1 and 1918.1, respectively.

According to the Chemical Economics Handbook, approximately 8.2 billion pounds of EtO were produced in the U.S. in 1999. Nearly all (99.2%) of the EtO consumed in the U.S. was domestically produced; only 1.7 million pounds of EtO were imported in 1999. It was projected that 7.8 billion pounds would be produced in 2003 (CEH, Oct. 2003). Most of the EtO was used as a process input by various chemical manufacturing industries; for example, only 8 to 9 million pounds of the 7.3 billion pounds was used in fumigant or sterilant applications in 1996². The industry profile that follows has, therefore, been broadly divided into two groupings: (1) chemical manufacturing industries (e.g., EtO producers and ethoxylators) and (2) industries that use EtO as a sterilant or fumigant (e.g., hospitals and commercial sterilizers such as medical products manufacturers, spice manufacturers, and contract sterilizers).

Chemical Manufacturing Industries

Ethylene Oxide Producers

Producers manufacture EtO by the direct oxidation of ethylene. Producers of ethylene oxide are classified in SIC 2869, Industrial Organic Chemicals, Not Elsewhere Classified. The Small Business Administration (SBA) small firm definition for this industry is 1,000 employees.

According to the CEH, the U.S. ethylene oxide production industry has operated at annual capacity rates generally in the 84-89% range since 1985. Furthermore, this industry has added over 3 billion pounds of capacity since 1988. This capacity increase resulted from the addition of two new plants as well as significant capacity improvements made to six other existing plants. Domestic production of EtO has risen from 6.0 billion pounds in 1984 to 8.2 billion pounds in 1999. The economic situation of this industry has generally been favorable during these years.³

In 1984, in the Final Regulatory Impact Analysis for the Ethylene Oxide Standard, OSHA estimated that there were 13 domestic producers operating 16 EtO production facilities [Docket H-200, Ex. 164]. In 1999, there were 10 domestic producers of ethylene oxide operating 13 EtO production facilities. In 2003, there still were the 10 domestic producers, but they had consolidated production in 12 facilities. These producers are: BASF Corporation, Dow Chemical, Eastman Chemical Company, Equistar Chemical, Formosa Plastics Corporation, Huntsman Corporation, Old World Industries, PD Glycol, Shell Chemical Company, and Sunoco Inc.⁴ All of these companies are considered large firms, according to the SBA criterion for this industry. BASF, Equistar, Shell Chemical, and Sunoco are the four largest companies selling to the merchant market. Although there are fewer companies and facilities producing EtO than was the case in 1984, this is the result of mergers and consolidations within the chemical industry rather than a decrease in demand for EtO. As noted above, EtO production has increased substantially in this period.

In the Regulatory Impact Analysis for the 1988 excursion limit rulemaking, OSHA estimated that there were approximately 1,046 employees exposed to EtO during its production [53 FR 11421]. This estimate was taken from a report by Heiden Associates that was submitted to OSHA by the Ethylene Oxide Industry Council (EOIC) during the 1988 rulemaking [Docket H-200B, Ex. 205-6B].⁵ In this report, Heiden Associates estimated that, on average, there were 80.5 affected employees per EtO production unit. Heiden Associates also provided other data indicating that there were approximately 1.1 EtO production units per EtO production facility. In order to update the estimate of EtO production workers, OSHA first multiplied these estimates to derive an average total of 88.6 workers per facility. OSHA then multiplied the 1999 number of production facilities (13) by an average of 88.6 employees per facility. OSHA estimates that in 1999 there were approximately 1,151 employees currently employed in EtO production and, therefore, potentially exposed to EtO. This represents about a 9 percent increase in the number of employees potentially exposed to EtO in this industry compared with the number potentially exposed in1988.

Ethoxylators

Ethoxylators are chemical manufacturing firms that use EtO as a chemical feedstock to make chemical products such as ethylene glycol, glycol ethers, ethanolamines, surfactants, and other specialty chemicals. A total of 57 percent of all EtO is used to produce ethylene glycols. Many of the 10 current EtO producers listed above manufacture these products in addition to producing pure EtO. Producers of ethylene glycol and glycol ethers are classified in SIC 2869, Industrial Organic Chemicals, Not Elsewhere Classified. The SBA small firm definition for this industry is 1,000 employees. Producers of surfactants are classified in SIC 2843, Surface Active Agents, Finishing Agents, Sulfonated Oils, and Assistants. The SBA small firm definition for this industry is 500 employees. Most ethoxylators would thus be large companies according to the SBA definition.

In the 1984 Final Regulatory Impact Analysis, OSHA estimated that there were 50 ethoxylator firms in the United States in addition to those EtO producers then engaged in operating ethoxylation units [Docket H-200, Ex. 164]. The EtO producers listed above still produce nearly all of the ethylene glycol, glycol ethers, and ethanolamines generated by ethoxylation processes.⁶ Ten EtO producer firms operate 11 ethoxylation facilities manufacturing one or more of these products. In addition, one specialty chemical manufacturer that does not produce EtO produces glycol ethers at a single facility. Additional firms engage in the manufacture of surfactants and other specialty chemicals via ethoxylation processes. To update the estimate of the number of ethoxylator firms currently in operation, in addition to those engaged in the primary production of EtO, OSHA reviewed recent CEH reports containing information on producers of EtO-based surfactants.

EtO is used as a process input during the production of three different types of surfactants: alcohol ether sulfates, alcohol ethoxylates, and alkylphenol ethoxylates. These surfactant compounds are used to manufacture shampoos, light-duty liquid dish detergents,⁷ heavy-duty laundry detergent powders and liquids, and specialty cleansers.⁸ In 1994, the CEH reported that there were 12 firms, with a total of 29 facilities, engaged in producing alcohol ether sulfates.⁹ In 1996, there were 19 firms, with a total of 29 facilities, engaged in producing alcohol ethoxylates and 3 additional firms engaged in producing alkylphenol ethoxylates.¹⁰ After adjusting this total for double-counting, OSHA estimates that there are approximately 21 stand-alone ethoxylator firms engaged in the production of surfactants through ethoxylation reactions and that these 21 firms operate a total of 46 surfactant ethoxylation facilities. (In addition, 4 EtO producer firms operate a total of 9 surfactant ethoxylation facilities; 3 of the 9 facilities are presumably facilities already counted above, because they are sited at locations where ethylene glycol, glycol ethers, and ethanolamines are manufactured.) Therefore, OSHA estimates that there are at a minimum approximately 22 firms uniquely covered by the ethoxylator industry grouping (the 21 surfactant producers plus the 1 glycol ether manufacturer).

In the Regulatory Impact Analysis for the 1988 EL rulemaking, OSHA estimated that there were approximately 1,436 employees exposed to EtO during ethoxylation processes [53 FR 11421]. This estimate was also taken from the Heiden Associates report on EtO production and ethoxylation operations cited above [Docket H-200B, Ex. 205-6B]. Heiden Associates estimated that, on average, there were 37.8 affected employees per EtO ethoxylation unit and also provided data indicating that there were approximately 1.6 ethoxylation units per ethoxylation facility. Therefore, in order to update the estimate of ethoxylation facility workers, OSHA first multiplied these estimates to derive an average of 60.4 workers per facility. OSHA next added the number of ethoxylation facilities producing ethylene glycol, glycol ethers, and ethanolamines (12) to the number of ethoxylation facilities producing surfactants (52),¹¹ to get the total number of ethoxylation facilities believed to be currently in operation (64). OSHA then multiplied this number (64) by the estimated average of 60.4 employees per ethoxylation facility, to obtain an estimate of 3,866 employees engaged in ethoxylation processes, more than twice the number estimated to be potentially exposed in this process in1988.

Industries That Use EtO as a Sterilant of Fumigant

During the 1984 and 1988 EtO rulemakings, OSHA concluded that industries using EtO as a sterilant or fumigant would also be affected by the EtO standard. In the regulatory impact analyses accompanying the two rulemakings, OSHA identified the following industries where EtO was used as a sterilant or fumigant as industries that would be impacted by the standard: hospitals, medical products sterilizers, and spice manufacturers.¹² In the 1988 Regulatory Flexibility and Impact Analysis, OSHA retained its 1984 estimates of approximately 6,300 hospitals, 125 medical products sterilizers, and fewer than 30 spice manufacturers [53 FR 11421]. However, in that analysis, OSHA provided new, and lower, estimates of the number of workers exposed to EtO during sterilization and fumigation operations. In 1988, OSHA estimated that 65,246 workers were exposed to EtO during EtO sterilization and fumigation operations, with approximately 63,000 of these workers exposed to EtO in the hospital sector [53 FR 11421].

In conducting this Lookback review, OSHA has determined that EtO sterilization continues to be used in all of the industries identified in the 1984 and 1988 rulemakings. OSHA further concludes that EtO use for sterilization purposes is still most significant in the hospital industry and that the largest number of exposed workers is employed in that industry. The following discussion concerning industries using EtO as a sterilant or fumigant has therefore been divided into two groupings: (1) hospitals, and (2) commercial sterilizers (including all other industries identified by OSHA as currently engaged in significant EtO sterilization and fumigation operations).

A large number of EtO sterilization systems are currently in use in the hospital and commercial sterilization industries. Estimates from an article in Health Industry Today indicated that there were approximately 12,500 EtO sterilization systems in use in the U.S. in 1995.¹³ Nevertheless, OSHA also found evidence indicating that the number of hospitals using EtO sterilization systems has declined since 1984 (see the discussion below at pp. II-7 to II-9) and that much of the EtO sterilization of spices and, to a lesser extent, the sterilization of medical devices, has shifted from the manufacturers of these items to contract sterilizers (see the discussion at pp. II-13 to II-15). Some evidence was also found suggesting that there are several ongoing minor uses of EtO in sterilization and fumigation operations (e.g., laboratory sterilization operations, veterinary clinic sterilization operations, and fumigation of beekeeping equipment).

Hospitals

Hospitals use EtO as a sterilant for reusable and single-use items that would be damaged by steam sterilization or other sterilization processes. Examples of items requiring EtO sterilization include catheters, cardiac pulse generators, orthopedic prostheses, and other implantable medical devices [Docket H-200C, Ex. 2-2]. The use of EtO sterilization systems is common, but not universal, in the hospital setting. Two recent studies of EtO use in the hospital sector (discussed below) contain data suggesting that between 44% and 60% of U.S. hospitals have on-site EtO sterilization operations. Most hospitals are classified in SIC 8062, General Medical and Surgical Hospitals and SIC 8069, Specialty Hospitals. Table II-1 presents details on the number of American Hospital Association (AHA)-registered hospitals and the total number of beds, by ownership and hospital type, in 1980 and 1995.

The SBA small firm definition for profit-making enterprises in the hospital sector is $5 million in revenues. However, since most hospitals are either non-profit organizations or are owned by municipal governments, special size criteria apply. The Regulatory Flexibility Act defines a "small organization" as an organization that is independently owned and operated and is not dominant in its field. Furthermore, the SBA has defined a "small governmental jurisdiction" as an establishment that serves a population of less than 50,000. Table II-2 presents statistics on the distribution of community hospitals by size in order to provide some indication of the size distribution of entities in the hospital sector most likely to be affected by the EtO standard.

In the 1984 Regulatory Impact Analysis, OSHA estimated that there were 6,237 hospitals currently using EtO sterilizers [Docket H-200, Ex. 164]. The estimate of the number of affected hospitals was derived from the findings of a 1977 study by Z. R. Glaser.¹⁴ In that study, Glaser estimated that there were 8,100 hospitals in the United States. Glaser also presented an estimate indicating that 77 percent of hospitals belonging to the American Hospital Association (AHA) used EtO sterilizers. The estimated number of hospitals affected by the EtO standard was therefore generated by multiplying the estimated percentage of EtO-using hospitals by the total number of U.S. hospitals (8,100 hospitals x .77 = 6,237 EtO-using hospitals).

Table II-1
Number of American Hospital Association Registered Hospitals and Total Number of Beds
By Type of Ownership and Type of Hospital 1980 and 1995

Ownership and Type of Hospital	Number of AHA-Registered Hospitals		Percentage of Total AHA- Registered Hospitals		Total Number of Beds
Ownership and Type of Hospital	1980^a	1995^b	1980	1995	1980	1995
Federal	359	299	5.2	4.8	117,000	77,079
Non-federal, psychiatric, TB, and other respiratory disease hospitals	545	660	7.8	10.5	217,000	110,471
Non-federal, long-term general and other special hospitals	157	112	2.3	1.8	39,000	18,765
Hospital units of state/local govt. or nonprofit institutions	74	26	10.0	0.4	4,000	1,550
Community hospitals (non-profit)	3,322	3,092	47.7	49.1	692,000	609,729
Community hospitals (for-profit)	730	752	10.5	12.0	87,000	105,737
Community hospitals (state/local govt.)	1,778	1,350	25.5	21.5	209,000	157,270
Total	6,965	6,291	100.1^c	100.1	1,365,000	1,080,601
^aSource: JRB Associates, "Economic and Environmental Impact Study of Ethylene Oxide," Final Report, prepared for U.S. Department of Labor, OSHA, April, 1983. ^bSource: Hospital Statistics, AHA, 1996-1997 edition, Chicago, 1996. Data are from the 1995 annual survey of hospitals. ^cTotal is greater that 100 percent because of rounding.

Table II-2
Distribution of Community Hospitals^a by Bed Size Category

Hospital Size (Number of Beds)	Number of Community Hospitals		Percent of Community Hospitals		Total Number of Beds
Hospital Size (Number of Beds)	1980^b	1995^c	1980	1995	1980	1995
6-24	259	278	4.4	5.4	4,932	5,085
25-49	1,029	922	17.7	17.8	37,478	34,352
50-99	1,462	1,139	25.1	21.9	105,278	82,024
100-199	1,370	1,324	23.5	25.5	192,892	187,381
200-299	715	718	12.3	13.8	172,390	175,240
300-399	412	354	7.1	6.8	139,434	121,136
400-499	266	195	4.5	3.8	117,724	86,459
500+	317	264	5.4	5.1	218,259	181,059
Total	5,830	5,194	100.0	100.1^d	988,387	872,736
^aCommunity hospitals, as defined by the American Hospital Association (AHA), are non-federal acute-care facilities. ^bSource: JRB Associates, "Economic and Environmental Impact Study of Ethylene Oxide," Final Report, prepared for U.S. Department of Labor, OSHA, April, 1983. ^cSource: Hospital Statistics, AHA, 1996-1997 edition, Chicago, 1996. Data are from the 1995 annual survey of hospitals. ^dTotal is greater than 100 percent because of rounding.

In order to update the estimate of the number of EtO-using hospitals, OSHA reviewed recent AHA statistics concerning the number of AHA-registered hospitals and also reviewed the findings of two recent studies concerning EtO use in hospitals. Table II-1 indicates that, in 1995, there were a total of 6,291 AHA-registered hospitals--nearly a 10 percent decrease from the 6,965 hospitals registered in 1980. Most of these hospitals (5,194, or 82.5%) are community hospitals; these hospitals are defined by the AHA as non-federal, acute-care facilities. These statistics were used in conjunction with the data discussed below from studies of EtO use in the hospital sector in two states, Massachusetts and Colorado. As of 2002, there were 5,794 registered hospitals according to the AHA Resource Center, hospitalconnect.com, 10/13/04, continuing the slow consolidation of hospitals.

The first of two studies used by OSHA to estimate the current use of EtO in the hospital sector was the 1993 Massachusetts Hospital EtO Health and Safety Study conducted by Dr. Anthony LaMontagne [Docket H-200C, Ex. 2-9K].¹⁵ This study surveyed all 159 hospitals in the Commonwealth of Massachusetts and found that 92 of the 154 responding hospitals reported using EtO as a sterilant at their hospitals. Dr. LaMontagne therefore estimated that approximately 96 hospitals, or 60 percent of all hospitals in Massachusetts, used EtO in 1993. The Massachusetts Hospital Study also produced several other noteworthy findings, including the conclusions that (1) EtO-using hospitals are typically acute-care facilities, (2) EtO-using hospitals are more likely to be privately operated than non-using hospitals, and (3) EtO-using hospitals are somewhat larger on average than non-using hospitals [Docket H-200C, Ex. 2-9K]. With regard to the type of facility, 87 of the 92 EtO-using hospitals (95 percent) were acute-care facilities, while only 12 of the 62 non-using hospitals (19 percent) were acute care facilities. Taking hospital ownership into consideration, the study found that 76 of the 92 EtO-using hospitals were privately operated (83 percent), while only 33 of the 62 non-using hospitals (53 percent) were private hospitals. Finally, with regard to hospital size, the study found that EtO-using hospitals had an average of 253 patient beds versus 158 patient beds for hospitals that were non-users [Ex. 2-9K]. This information suggests that smaller hospitals may be somewhat less likely to use EtO and thus to have compliance responsibilities related to the EtO standard.

A second study, "Survey of Chemical Use in Colorado Hospitals," conducted in the fall of 1995 by Colorado Hospitals for a Healthy Environment (CHHE), also provided OSHA with useful data on the prevalence of EtO-using hospitals.¹⁶ CHHE surveyed 96 Colorado hospitals ranging in size from small rural institutions to large urban health care complexes about their chemical usage patterns. Fifty-two hospitals responded to this survey. CHHE commented that the 52 responding hospitals provided a "good representation of hospitals across Colorado." Furthermore, a significant number of the respondents to the CHHE survey were relatively small hospitals.¹⁷ Of the 52 respondents to the CHHE survey, 19 respondents (or 37 percent) reported using EtO, 29 respondents reported that they did not use any EtO, and there were 4 non-respondents to this question. The CHHE report did not present a distribution of EtO-using hospitals by ownership type or size class. However, the findings of the CHHE survey suggest that it would be reasonable to estimate that a maximum of 44% of Colorado hospitals are engaged in EtO use (19 EtO users + 4 non-respondents/52 respondents).

The findings of the Massachusetts Hospital EtO Health and Safety Study, in conjunction with the findings of the CHHE survey, suggest that the percentage of hospitals using EtO has declined significantly from the mid-1970's to the mid-1990's (77% of hospitals in 1977 versus a range of 44% to 60% during the mid-1990s). To derive an updated estimate of the number of such hospitals, OSHA averaged the 44% and 60% estimates to derive an estimated average of 52%. OSHA then multiplied this percentage by 6,291, the total number of AHA-registered hospitals in 1995, to derive an estimate of 3,271 EtO-using hospitals nationwide.

This estimated decrease in the number of EtO-using hospitals is explained, in part, by certain demographic trends occurring in the hospital sector. First, the total number of non-federal, acute-care community hospitals declined from 5,830 hospitals in 1980 to 5,194 hospitals in 1995 (see Table II-2). Since the findings of the Massachusetts Hospital Study indicated that acute-care facilities are particularly likely to use EtO, this reduction in the number of non-federal acute care community hospitals may have contributed to a decrease in the percentage of hospitals using EtO. Second, while the number of AHA-registered hospitals declined by almost 10 percent between 1980 and 1995, the number and percentage of smaller hospitals among AHA-registered hospitals increased (see Table II-2). This may also have had some significance for trends in EtO use in the hospital sector, since the Massachusetts Hospital Study found that, on average, EtO-using hospitals tend to be somewhat larger than non-using hospitals. There are no indications that costs of complying with the EtO Standard, which is a tiny fraction of the costs of operating a hospital, contributed to the decrease in number of hospitals.

In the 1984 Regulatory Impact Analysis, OSHA estimated that there were, on average, 10 directly exposed workers per EtO-using hospital facility. OSHA therefore estimated that there were 62,370 employees directly exposed to EtO in the hospital sector (6,237 hospitals x 10 directly exposed workers per hospital) [Docket H-200, Ex. 164].¹⁸ In order to update this estimate, OSHA used data from the Massachusetts Hospital Study, which reported that EtO-using sterilization departments in Massachusetts hospitals employed 12 workers on average [Docket H-200C, Ex. 2-9K]. OSHA multiplied this estimate of the average number of workers times the estimated number of EtO-using hospitals to calculate a total estimate of 39,252 workers exposed to EtO during hospital sterilization operations.¹⁹ This represents a decline of nearly 40 percent in the number of potentially exposed sterilization workers since 1984. However, a recent study indicates the EtO use for sterilization has stabilized or increased because of technological improvements. Also, some of the EtO sterilization which had been performed by hospitals and medical device manufacturers was being performed by contract sterilizers because of their lower costs. See K. Hemmerich, et al., Sterilization Methods Stand the Test of Time, MDDI, Aug. 2004, devicelink.com. This is based on 1997 hospital numbers. The Hospital Statistics 2004 estimates that there were 4% fewer hospitals in 2002. However, the hospitals averaged more employees and probably used more contractor sterilizers, so it would be difficult to estimate any further changes in the numbers of exposed workers.

Commercial Sterilizers

Firms that perform EtO sterilization as part of a production process are commonly referred to as commercial sterilizers. Commercial sterilizers can generally be classified into two groups: in-house sterilizers and contract sterilizers. In-house sterilizers produce goods requiring sterilization and sterilize them as part of their production process. (Some other types of entities that have been known to use EtO sterilization, such as laboratories, museums, and libraries, are also similar to in-house sterilizers because, although they do not produce the goods needing sterilization, sterilization is a small part of their routine operations.)²⁰ Contract sterilizers are companies that specialize in offering sterilization and/or fumigation services to clients. Contract sterilizers do not, in general, produce any of the goods being sterilized. The trend toward the use of contract sterilizers has continued throughout the 90s, as more and more companies focus on their core business and contract out other services that they need.

During the 1988 rulemaking, OSHA examined the use of ethylene oxide in two industries where commercial sterilization processes were performed: the medical products sterilization and spice manufacturing industries. As indicated above, at that time, OSHA used estimates from the 1984 rulemaking of 125 medical products sterilizers and fewer than 30 spice manufacturers [FR Vol. 53, No. 66, 4/6/88, p. 11421]. During the process of updating this industry profile, OSHA found very little current data on industries where commercial sterilization operations occur. Some of the best publicly available data identified by OSHA was found in a 1993 Environmental Protection Agency (EPA) background information document. This document was produced to support an EtO air emissions standard for commercial sterilization operations that was promulgated in 1994 (the National Emission Standards for Hazardous Air Pollutants (NESHAP) for Ethylene Oxide Commercial Sterilization and Fumigation Operations).²¹ The information in this EPA document is more current than the data OSHA relied on in the 1988 rulemaking, and it also presents more recent estimates of the number of affected small entities.²²

The EPA document estimates that, in 1988, there were 188 facilities engaged in commercial sterilization operations. EPA grouped these facilities into seven major categories: medical equipment suppliers (62 facilities); other health-related suppliers (24 facilities); pharmaceutical manufacturers and other drug-related manufacturers (39 facilities); spice manufacturers and other food-related manufacturers (23); museums and libraries (13); research, testing, and animal breeding laboratories (10); and contract sterilizers (17). Table II-3 presents these estimates, along with EPA's estimates of the number of these facilities that belonged to firms meeting the EPA definition of "small entity."²³ (In later research, EPA also identified the fumigation of privately owned beekeeping equipment by state government Departments of Agriculture as a limited use of EtO as a fumigant.)

Table II-3
Number of Commercial Sterilization Facilities Using Ethylene Oxide

Industry Group	SIC Codes^a	Number of Facilities	Number of Small Entities^b
Medical Equipment Suppliers	3841, 3842	62	6
Other Health-Related Suppliers	3079, 3693, 5086, 2821, 2211 2879, 3069, 3569, 3677, 3999	24	5
Pharmaceutical Manufacturers	2834, 5122, 2831, 2833	39	2
Spice Manufacturers	2099, 5149, 2034, 2035, 2046	23	3
Contract Sterilizers	7389, 7218, 8091	17^c	12
Museums and Libraries	8411, 8231	13	4
Laboratories	0279, 7391, 8922, 8071, 7397	10	2
Environmental Protection Agency, OAR/OAQPS, Ethylene Oxide Emissions from Commercial Sterilization/Fumigation Operations--Background Information for Proposed Standards (Pub. No. EPA-435/D-93-016), March 1993, Tables 8-2; 8-20. ^aSICs are listed in order of frequency of establishments reporting that SIC. ^bBased on EPA's definition of small entities as those having annual sales of less than $3.5 million. ^cWhile EPA was collecting the data, one contract sterilizer ceased use of EtO.

In order to update the industry profile for commercial sterilizers, OSHA relied heavily on the findings of this EPA research. However, OSHA chose to revise the groupings used by the EPA to reflect the groupings used by OSHA in the EtO rulemakings. Thus, the EPA profile of commercial sterilizers that follows is broken into the following groupings: (1) medical and pharmaceutical product manufacturers, (2) spice manufacturers, (3) contract sterilizers, and (4) other sterilization and fumigation applications.

Medical and Pharmaceutical Product Manufacturers

Medical products manufacturers use EtO to sterilize equipment, medical devices, and supplies that might be damaged by other sterilization methods. Some examples include x-ray equipment and catheters. A breakdown of the sterilization methods used for medical products in 1995 indicated that EtO was used as the sterilization method 52 percent of the time, while gamma radiation was used 46 percent of the time. Steam sterilization comprised less than 2 percent, and other methods 0.1 percent, of all methods used.²⁴ Most EtO-using medical products manufacturers are found in SIC 3841, Surgical and Medical Instruments and Apparatus, and SIC 3842, Orthopedic, Prosthetic, and Surgical Appliances and Supplies. However, these manufacturers are found in a number of other SICs as well, reflecting the diversity of products that can be sterilized using EtO. The SBA small business size definition for both SICs 3841 and 3842 is 500 employees.

A few pharmaceutical products manufacturers use EtO to sterilize products such as bulk powders, ingredients used in ophthalmic ointments and suspensions, and packaging materials. These uses seem to be in decline. In particular, according to the FDA, use of EtO in bulk powder sterilization appears to have been declining because of difficulties related to verifying the sterility of the product after sterilization cycles have been completed.²⁵ Most pharmaceutical manufacturers are typically found in SIC 2834, Pharmaceutical Preparations. The SBA small business size definition for this industry is 750 employees.

According to Bureau of Census data, in 1994, there were approximately 2,817 firms and 3,138 establishments in the main SICs for medical products sterilization (SICs 3841 and 3842);²⁶ 2,479, or 88 percent, of these firms employ fewer than 500 employees. With regard to pharmaceutical firms, according to the Census data, there were approximately 592 companies and 707 establishments in SIC 2834 in 1994. Four hundred eighty-five, or 82 percent, of these firms employ fewer than 500 employees (employee size breakdowns to match the SBA size definition of 750 employees were not available from the SBA's data). Only a small subset of medical and pharmaceutical products manufacturers appears to perform EtO sterilization in house, probably because medical and pharmaceutical product manufacturers typically make significant use of contract sterilization services. According to the findings of a survey conducted by CMR and MDS Nordion in 1996, a total of 87 percent of health care manufacturers were using contract sterilization services for their products.²⁷ In addition, health care manufacturers also have the option to use other sterilization methods such as gamma radiation and e-beam sterilization technologies (see Chapter V for more details).

In 1984, OSHA estimated that there were 125 medical products sterilization firms (including both medical product manufacturers and contract sterilizers of medical products) [Docket H-200, Ex. 164]. In the 1988 STEL rulemaking, OSHA used an estimate from a second Heiden Associates report submitted to OSHA by the Ethylene Oxide Industry Council (EOIC) to revise its estimates of the number of affected workers in medical products sterilization; this estimate of the number of workers was based on an estimate of 95 medical product sterilizing facilities.²⁸

OSHA has concluded that the EPA data presented above in Table II-3 are the best data available for updating the number of affected firms in the medical products and pharmaceutical manufacturing sectors. These data are particularly useful because they permit contract sterilizers to be identified and discussed as a separate industry grouping. As shown in Table II-3, in 1988, approximately 86 medical products manufacturing facilities nationwide used EtO to sterilize medical equipment and other health-related products and 39 pharmaceutical facilities used EtO to sterilize pharmaceutical products. In 1988, EPA also identified 11 medical product manufacturing facilities and 2 pharmaceutical manufacturing facilities as facilities owned by small businesses, based on a sales level small business size criterion of $3.5 million.

In the Regulatory Impact Analysis for the 1988 rulemaking, OSHA estimated that there were approximately 1,814 employees exposed to EtO during medical products sterilization processes [FR Vol. 53, No. 66, 4/6/88, p. 11421]. This estimate was based on an average of 19.1 exposed employees per facility taken from the Heiden Associates report on EtO use in the medical products industry [Docket H-200B, Ex. 205-6]. This estimate remains the best estimate of the average number of workers exposed per medical product sterilization facility. OSHA therefore multiplied the number of medical products manufacturing facilities (86) times 19.1 workers per firm to obtain an updated estimate of 1,643 exposed employees employed by medical products manufacturers. In the absence of more specific data, OSHA is using the same estimate of 19.1 exposed employees per facility to estimate employment in the pharmaceutical manufacturing industry. To derive the number of employees exposed in this industry, OSHA multiplied the number of pharmaceutical manufacturing facilities (39) times 19.1 workers per firm to yield an adjusted estimate of 745 EtO exposed employees employed by pharmaceutical manufacturers.

Spice Manufacturers

Spice manufacturers use EtO to fumigate spices to prepare them for sale. EtO is used to reduce the microbial load and to kill pathogens on select spices such as black pepper, paprika, and cassia. Each year, approximately 15% to 22% of the total sales volume of spices sold in the U.S. (imported and domestic) is fumigated with around 500,000 pounds of EtO [Docket H-200C, Exs. 2-8; 2-8C]. Fumigation is either conducted in-house with state-of-the-art equipment or by contract fumigators [Docket H-200C, Ex. 2-8].

Spice manufacturers are typically classified in SIC 2099, Food Preparations, Not Elsewhere Classified. This SIC has an SBA size class definition of 500 employees. In the Regulatory Flexibility Analysis for its 1994 NESHAP on commercial sterilizers, the EPA concluded that only a few EtO-using spice manufacturing facilities were small businesses, based on a sales threshold of $3.5 million. As shown in Table II-3, the EPA determined that, in 1989, there were 3 EtO-using spice manufacturing facilities owned by small businesses.

In 1984, OSHA reported that there were approximately 25 spice manufacturers and 150 employees exposed to EtO in this industry [Docket H-200, Ex. 164]. However, the structure of the spice manufacturing industry has changed dramatically since the 1984 rulemaking. The downsizings, consolidations, and increase in foreign ownership that have occurred in the spice manufacturing industry since 1989 have apparently led to a substantial decrease in the number of EtO-using spice manufacturers, although exact statistics are not available [Docket H-200C, Ex. 2-8C].²⁹ None of these changes are related to the use of EtO as a sterilant.

In 1989, the American Spice Trade Association (ASTA), the major trade association for the spice industry, reported that 16 ASTA spice trade companies used EtO in their own facilities [Docket H-200C, Ex. 2-8C]. (It is possible that these companies operated more than one facility, because EPA reported that there were 23 facilities using EtO in the spice manufacturing sector in 1989 (see Table II-3).) In 1989, ASTA also reported that approximately 22 percent of the total U.S. sales volume of spices had been treated with EtO during that year [Docket H-200C, Ex. 2-8C].

In a 1995 survey, ASTA resurveyed the 16 ASTA member companies that had used EtO in 1989 and reported that "many" of them now use outside contractors to treat their spices [Docket H-200C, Ex. 2-8C].³⁰ Though OSHA is not aware of a more recent survey, a more recent article indicates the growth of contract sterilization because of lower costs, Hemmerich, 2004, supra p. II-9. The 1995-1996 ASTA survey results also indicated that approximately 15 percent of the spices handled by the 16 companies surveyed were treated with EtO. (However, since this finding applied to only 70 percent of its members' total sales volume of spices, and because EtO manufacturers have reported a constant level of EtO use by the spice industry, ASTA concluded that this finding did not necessarily suggest a decline in the total volume of spices sterilized with EtO.) Approximately 94% of EtO-treated spices produced by the 16 ASTA survey respondents were treated by the largest contract sterilizer [Docket H-200C, Ex. 2-8C]. EPA also submitted comments indicating that spices sent to contract sterilizers are usually handled by one of four large contract fumigators [Docket H-200C, Ex. 2-8]. Thus, although the exact numbers are not available, the number of spice manufacturing firms using EtO to sterilize spices in-house is likely to be very small, and thus very few small spice manufacturing firms are potentially affected. Similarly, most of the employees exposed during fumigation of spices with EtO are likely to be employed by contract sterilizers rather than by the spice manufacturers themselves.

Contract Sterilizers/Fumigators

Contract sterilizers sterilize and fumigate products for manufacturing sector clients. These firms may use any of a variety of sterilization technologies, including EtO sterilization, gamma irradiation, e-beam sterilization, and steam sterilization. Some contract sterilizing firms specialize in only one sterilization method, while other firms can provide multiple sterilization methods. Some examples of products commonly processed by contract sterilizers include medical products, pharmaceuticals, food products, spices, cosmetics, seeds, and packaging. According to one estimate, the U.S. market for contract sterilization was approximately $170 million in 1996.³¹

Contract sterilizers are typically classified in SIC 7389, Business Services, Not Elsewhere Classified. This SIC currently has an SBA size class definition of $5.0 million dollars in annual sales. In the Regulatory Flexibility Analysis for its 1994 NESHAP on commercial sterilizers, the EPA concluded that contract sterilization firms were often small firms. As shown in Table II-3, the EPA estimated that 12 of 16 contract sterilizers identified during the process of developing the Regulatory Flexibility Analysis were small businesses according to EPA's criterion of $3.5 million in sales (one of the original 17 contract sterilizers identified by EPA had discontinued use of EtO by the time the analysis was concluded).

According to the findings of a survey conducted by CMR and MDS Nordion in 1996, a total of 87 percent of health care manufacturers are currently using contract sterilization services for their products.³² In addition, as described above, many of the spice manufacturers who sell EtO-treated spices now utilize contract sterilization services. Information gathered during this Lookback review suggests that medical device and spice manufacturers are increasingly turning to the use of contract sterilizers and fumigators to concentrate on their core businesses. For example, the CMR and MDS Nordion survey indicated that manufacturers of single-use medical devices had increased the volume of devices sterilized by contract sterilizers from 50% to 55% over a two-year period between 1994 and 1996.

Most of the publicly available information concerning the contract sterilization industry focuses on the sterilization of medical products, since sterilization of these products represents a significant portion of most contract sterilizers' businesses. (To take just one example, in 1997, one large contract sterilizing company that performs both gamma radiation and EtO sterilization reported that 80 percent of its business involves medical device sterilization.)³³ According to an article in Plastics News, approximately 50 to 55 percent of the contract sterilization of medical devices utilizes EtO, 40 to 45 percent utilizes gamma radiation, and approximately 5 percent utilizes electron-beam sterilization techniques.³⁴

According to an article published in the Biomedical Market Newsletter, there were 152 FDA-registered establishments engaged in contract sterilization of medical devices nationwide in 1996.³⁵ This number of establishments includes all contract sterilizers of medical devices, regardless of the type of sterilization process performed, and may also include contract manufacturers who both manufacture and sterilize medical devices under contract to other firms (any such contract manufacturers using EtO would also have been included above under medical products manufacturers). The number of contract sterilizing facilities using EtO is likely to be much smaller than the number of FDA-registered contract sterilizing establishments, although precise statistics are not available.

As shown above in Table II-3, EPA estimated that there were 17 contract sterilizer facilities where EtO was being used. One facility discontinued using EtO during EPA's rulemaking process, leaving 16 EtO-using contract sterilization facilities. OSHA believes that these are the best available data on the number of EtO-using contract sterilization facilities and that it is a reasonable estimate of the number of affected facilities, since OSHA's review indicates that EtO use in the contract sterilization industry is highly concentrated. (As described above, most EtO-treated spices are handled by just four contract sterilization firms [Docket H-200C, Ex. 2-8].)

Information on contract sterilizing firms suggests that the number of potentially exposed workers per facility is likely to be small. One large contract sterilizing firm that offers both gamma radiation and EtO sterilization employs 500 people and operates 11 facilities (45 employees per facility).³⁶ Another contract sterilizer that specializes in EtO sterilization and identifies itself as one of the largest sterilization contractors in the U.S. employs 150 people and operates 6 facilities (25 employees per facility).³⁷

In 1984 and 1988, the estimated number of employees of contract sterilization firms engaged in medical products sterilization was included in the total medical products sterilization estimates [Docket H-200, Ex. 164]. In the Regulatory Impact Analysis for the 1988 rulemaking, OSHA used an estimated average of 19.1 exposed employees per facility (taken from the Heiden Associates report on EtO use in the medical products industry) to estimate the number of workers affected at firms engaged in medical products sterilization [Docket H-200B, Ex. 205-6]. This estimate remains the best estimate of the average number of workers exposed at contract sterilization facilities. OSHA therefore multiplied the number of contract sterilization facilities (16) times 19.1 workers per firm to obtain an updated estimate of 306 EtO exposed employees employed by contract sterilizing firms. However, a recent article indicates that there is some growth in the contract sterilization industry because of its lower costs, Hemmerich, 2004, supra. P. II-9.

Other Sterilization and Fumigation Applications

EPA research conducted after the promulgation of EPA's 1994 EtO air emissions standard indicates that museums and libraries have largely discontinued EtO use [Docket H-200C, Ex. 2-8]. EPA found that routine use of EtO to treat museum specimens was discontinued because standard aeration times of EtO-treated specimens could not be established, making it impossible to determine when the articles could be safely handled. Library items may still be sent to contract sterilizer facilities for EtO fumigation as a last resort to treat major outbreaks of mold [Ex. 2-8]. OSHA therefore assumes that there are no longer any entities using in-house EtO sterilizers in these industry sectors.

The use of EtO as a sterilant and fumigant in laboratory and beekeeping applications appears to be very minor. EPA reported in 1988 that 10 laboratory firms used EtO at that time. Four of these firms were commercial laboratory rat and mice breeders who used EtO to sterilize plastics, equipment, and articles used to operate the animal breeding facilities. The remaining facilities appeared to be specialized research laboratories. The fumigation of beekeeping equipment is also a minor use of EtO. Only two State Departments of Agriculture currently hold the EPA registrations required to perform fumigation of beekeeping equipment [Docket H-200C, Ex. 2-8].

Summary

The industry definitions used in the data sources relied on to make estimates of the number of workers exposed to EtO at the time of the 1984-1988 rulemakings and in the sources used to estimate the potentially exposed workforce for this Lookback review have some differences. For example, OSHA apparently included pharmaceutical product manufacturers in the medical products manufacturing group in 1984, and current data separate these two groups. Although these differences make comparisons somewhat difficult, OSHA believes that the number of potentially exposed workers has declined from about 66,000 in the 1984-1988 period to about 46,000 in the late '90s, a drop of approximately 30 percent. This change does not indicate any loss of employment from the EtO standard. Some employers who were not experts or larger users of EtO sterilization switched to contract sterilizers and others may have switched to alternatives. The affected industries continue to grow. Few employees outside of contract sterilizers, spent the majority of their time sterilizing.

EMPLOYER COMPLIANCE EXPERIENCE WITH THE STANDARD

As part of this Lookback review, OSHA analyzed the compliance experience of affected firms to aid in determining whether the standard was imposing a significant impact on them. During the review, special attention was given to information concerning the compliance experience of small businesses and other entities. OSHA evaluated three major sources of information on the compliance experience of affected firms in addition to the public comments submitted to the docket for this review [Docket H-200C]. These sources were: (1) an analysis of OSHA enforcement and consultation program data, (2) input provided by OSHA enforcement and State-plan State officials, and (3) a review of the occupational safety and health literature relating to the EtO standard.

Analysis of Enforcement and Consultation Program Data

Enforcement Program Data

Since the effective date of the EtO standard in February 1985, OSHA has conducted several hundred inspections during which worker exposures to ethylene oxide were monitored. During this period, three OSHA regions (Regions II, III, and VIII) also conducted local emphasis programs targeting EtO hazards. In recent years, OSHA enforcement staff has also responded to reports of EtO releases in hospitals as well as to reports of fires and explosions occurring at EtO-using facilities in other industries.

The EtO standard is not frequently cited. For this review, OSHA analyzed the patterns in recent enforcement data in two ways. The first analysis evaluated data on the industries inspected and the numbers of inspections where §1910.1047 was cited in FY 1996, 1997 and 2000. The second analysis consisted of an analysis of patterns found in the distribution of citation data by size class of the firms cited for the period in which the EtO standard has been in effect.

Analysis of Industries Inspected

OSHA analyzed enforcement data to determine whether facilities in covered sectors continued to be cited for non-compliance and to examine patterns in OSHA enforcement activity by the size class of firms inspected. In Fiscal Year 1996, across all size classes of business, there were 12 federal inspections in which §1910.1047 was cited. Nine of the inspections occurred at firms employing more than 250 employees, and three occurred at firms employing between 20 and 99 employees. Eight inspections occurred in SIC 8062, General Medical and Surgical Hospitals. There was one inspection in each of the following four SICs: (1) SIC 2821, Plastics Materials, (2) SIC 3841, Surgical and Medical Instruments and Apparatus, (3) SIC 0742, Veterinary Services, and (4) SIC 8011, Doctors' Offices.

In Fiscal Year 1997, across all firm size classes, there were 13 federal inspections where §1910.1047 was cited. Eight of these inspections occurred at firms employing more than 250 employees. One inspection occurred at a firm employing between 100 and 250 employees, 1 at a firm with between 20 and 99 employees, and 3 at firms with 1 to 19 employees. The data on the industries inspected indicated that there were 3 inspections in SIC 8069, Specialty Hospitals, and 2 in SIC 8062, General Medical and Surgical Hospitals. In addition, there was one inspection in each of the following eight SICs: (1) SIC 2865, Cyclic Organic Crudes and Intermediates, (2) SIC 2869, Industrial Organic Chemicals, Not Elsewhere Classified, (3) SIC 3599, Industrial and Commercial Machinery and Equipment, Not Elsewhere Classified, (4) SIC 3841, Surgical and Medical Instruments and Apparatus, (5) SIC 3842, Orthopedic, Prosthetic, and Surgical Appliances and Supplies, (6) SIC 8099, Health and Allied Services, Not Elsewhere Classified, (7) SIC 8711, Engineering and Architectural Services, and (8) SIC 8733, Noncommercial Research Organizations. An update of the citation history for EtO in FY 2000 shows that the EtO standard was cited 10 times during Federal inspections of facilities in SIC 80 in that year.

Because of the small size of this data set, only limited conclusions can be drawn. In these three fiscal years, the industries in which the EtO standard has been cited are largely the same industries that OSHA identified as affected during the rulemaking process: the chemical manufacturing industries and the industries where EtO is used as a sterilant or fumigant (e.g., the hospital sector and the medical product manufacturing industries). In addition, the firms that received citations during the last few years were mainly large firms. In SIC 80, which includes hospitals and other health service providers and is the industry with the largest number of EtO-exposed employees, Federal OSHA cited this standard between 6 and 10 times a year in 1996, 1997, and 2000.

Analysis of Violations Cited

OSHA also conducted an analysis of Federal OSHA citation data from 1985 through 1997 in order to determine which provisions of the standard were most frequently violated and to evaluate the most common compliance problems experienced by firms of different sizes. Table II-4 presents citation data for the top five most frequently cited provisions of the standard by firm size class. Across all three size classes, the most commonly cited provisions were §1910.1047 (h)(1) and (j)(3). Paragraph (h)(1) requires a written emergency plan, and paragraph (j)(3) requires employee training on EtO hazards. As shown in Table II-4, the majority of the citations issued (74%) were issued to large employers--employers with more than 500 employees.

Table II-4
Top Five Most Frequently Cited EtO Standard Provisions,
By Size-Class of Firm Inspected, Using Citation Data from 1985-1997

Rank

Top Five Provisions Cited (and Number of Citations), by Firm Size*

Firms With 1-99 Employees

Firms With 100-500 Employees

Firms With 500+ Employees

(h)(1)

(40)

(h)(1)

(31)

(h)(1)

(223)

(j)(3)

(33)

(j)(3)

(23)

(j)(3)

(188)

(d)(2)

(26)

(g)(1)

(20)

(k)(2)

(137)

(j)(1)

(22)

(d)(2), (f)(1),
(g)(3), (h)(2)

(17)

(d)(1)

(108)

(c)(1)

(18)

----------------------

(h)(2)

(105)

(c)(1) Permissible Exposure Limit--8 hour TWA PEL
(d)(1) Exposure Monitoring--general exposure monitoring requirement
(d)(2) Exposure Monitoring--representative sampling requirement
(f)(1) Methods of Compliance--engineering control and work practices requirement
(g)(1) Respiratory Protection--general respirator requirement
(h)(1) Emergency Situations--general written plan requirement
(h)(2) Emergency Situations--means of alerting employees requirement
(j)(1) Communication of EtO Hazards--general signs and labels requirement
(j)(3) Communication of EtO Hazards--training requirement
(k)(2) Recordkeeping--exposure monitoring recordkeeping requirement

Sources: OSHA IMIS Enforcement Database; 29 CFR 1910.1047
*The total number of citations issued, by firm size class, from 1985 to 1997 were: 332 (firms with 1-99 employees), 270 (firms with 100-499 employees), and 1,677 (firms with 500 or more employees), for a total of 2,279 citations.

Consultation Program Data

Since 1984, OSHA consultation program staffs have conducted several hundred consultation visits that involved assessments of ethylene oxide exposure levels, with a large percentage of these visits occurring in 1984 and 1985, immediately following the promulgation of the standard. Most of these 1984-85 visits were in the hospital sectors in SIC 80. The remaining visits occurred in other health care settings such as medical doctors' offices and at medical product and device manufacturing establishments. The exposure data collected during consultation visits, like the exposure data collected during compliance visits, indicate that occupational EtO exposures were typically quite low following the promulgation of the standard (see Chapter III).

Review of the Literature on Employer Compliance Experience

As part of this Lookback review of the EtO standard, OSHA reviewed the occupational safety and health literature as well as other relevant studies to find and evaluate information on the compliance experience of affected businesses, entities, and industries. During this review, OSHA did not find any evidence of recent research on the compliance experience of employers in the chemical manufacturing industries (EtO producers and ethoxylators). The limited information in the existing literature suggests that the chemical manufacturing firms affected by the standard have continued to use conventional engineering controls and work practices to comply with the standard [Docket H-200C, Exs. 2-6G; 2-9J]. Similarly, most of the articles concerning EtO use as a sterilant or fumigant addressed the potential for EtO use reduction or substitution rather than employers' compliance experience. All of the directly relevant literature identified by OSHA during this Lookback review addressed compliance issues in the hospital sector. This is consistent with OSHA's conclusion that the hospital sector continues to be the industry most affected by the standard.

Many of the works related to hospital sector compliance that were identified by OSHA were journal articles authored by Dr. Anthony LaMontagne of the New England Research Institutes and his various co-authors (as cited below). These journal articles presented information on aspects of hospital sector compliance drawn from the findings of a 1993 study known as the Massachusetts Hospital EtO Health and Safety Study. A summary of the findings of this comprehensive study is provided below. In addition to these articles, OSHA also reviewed the findings of two additional studies. The first study, "Ethylene Oxide: A Case Study in Hazard Identification, OSHA Regulation, and Market Response," was prepared by Meridian Research, Inc., under contract to OSHA in 1992. The second study, "Gauging Control Technology and Regulatory Impacts in Occupational Safety and Health--An Appraisal of OSHA's Analytic Approach," was prepared by the Congressional Office of Technology Assessment in 1995. Brief discussions of these studies are provided below.

The Massachusetts Hospital EtO Health and Safety Study

The Massachusetts Hospital EtO Health and Safety Study evaluated the compliance patterns of nearly all (96 percent) of the EtO-using hospitals in the Commonwealth of Massachusetts during the period 1985 to 1992.³⁸ Although the study results indicated widespread awareness and implementation of the EtO standard in the hospital sector and demonstrated that the standard has been successful in reducing worker exposures, some of the study's detailed findings suggested that there were portions of the standard with which there has been delayed or incomplete compliance over the period from 1985 to 1992. The findings also indicated that sterilizing department managers experience some difficulty understanding the regulatory intent of portions of the exposure monitoring, emergency alert, and medical surveillance provisions. The study also concluded that OSHA enforcement efforts in Massachusetts had led to improved compliance with the EtO standard.

Exposure Monitoring Findings from the Massachusetts Hospital Study

The Massachusetts Hospital EtO Health and Safety Study found that, by 1993, almost all EtO-using hospitals in Massachusetts had conducted personal monitoring to characterize worker exposure and to monitor compliance with the EtO standard's permissible exposure limits. By 1993, 95% of hospitals (87 of 92) had performed monitoring for the action level and 87% (80 of 92) had performed monitoring for the excursion limit.³⁹ However, the study findings indicate that most hospitals did not comply with this requirement until after the 1985 personal exposure monitoring implementation deadline and that some hospitals had not yet complied with the initial monitoring requirements as of 1993.⁴⁰ The authors concluded that OSHA enforcement activities had stimulated compliance with the exposure monitoring requirements in Massachusetts.

Most hospitals that monitored did so more frequently than the standard would have required them to do, and they also tended to monitor periodically regardless of the results of their exposure monitoring findings. Most occupational exposure measurements collected by the hospitals that provided their exposure monitoring results to Dr. La Montagne were quite low. Of the exposure monitoring data collected by surveyed hospitals during 1990 to 1992, only 0.4% of samples exceeded the action level (47/10,981) and only 0.7% exceeded the excursion limit (64/8,916). This finding indicates that occupational exposures are generally very low in hospitals and that employers are able to comply with the PELs. However, the study also reported that exposures above the action level or excursion limit were measured at a number of hospitals, and that such exposures continued to occur during 1990 to 1992 (the most recent period evaluated).⁴¹

Emergency Situation Findings from the Massachusetts Hospital Study

The Massachusetts Hospital Study found significant compliance with the emergency situation requirements of the standard. Ninety-four percent of EtO-using hospitals (85 of 90) had implemented a written emergency response plan by 1993.⁴² Furthermore, by 1993, 66% of EtO-using hospitals (59 of 90) in Massachusetts had elected to install EtO alarms to comply with the emergency alert requirement.^43,44 (EtO alarms are not required by the standard, although they are a common means of compliance with the emergency alert requirement.) Here again, the Hospital Study findings show that the installation of alarms occurred later than the 1985 compliance deadline for the EtO standard and peaked following a series of OSHA inspections and citations in Massachusetts hospitals.⁴⁵

Despite a high degree of compliance with the PELs and the EtO exposure monitoring and emergency situation requirements, a number of Massachusetts hospitals experienced accidental releases during the period studied. Approximately two-thirds of the responding hospitals (58 of 90) reported evacuations of the sterilization department or area in response to a real or suspected EtO leak or an EtO alarm at some time during 1985 to 1993. Fifty percent of these hospitals (46 of 92) reported accidental releases during the period 1985 to 1993 and 33% of hospitals (32 of 90) reported accidental releases during the period 1990 to 1992.⁴⁶

Medical Surveillance Findings from the Massachusetts Hospital Study

Hospital sector compliance with the medical surveillance requirements of the EtO standard was extensively studied during the Massachusetts Hospital EtO Health and Safety Study. The Hospital Study results indicated that medical surveillance had been provided one or more times at 62% (57 of 92) of EtO-using hospitals between 1985 and 1993. During the period from 1990 to 1992, 53% (48 of 90) of EtO-using hospitals reported providing surveillance. The study investigators also found that 11% of the hospitals (10 of 92) failed to provide medical surveillance in situations where the requirement should have been triggered.⁴⁷ Medical surveillance was most commonly provided on a single occasion (typically in response to a potential overexposure occurring during an accidental release of EtO).

The Hospital Study found that many EtO-using hospitals offered routine, periodic EtO surveillance. In general, however, the provision of medical surveillance was most strongly related to the occurrence of accidental exposure situations. Eighty-nine percent of the 52 hospitals reporting worker exposure to accidental EtO releases also reported providing medical surveillance.⁴⁸ In addition, the medical surveillance content of EtO health and safety training was strongly related to the provision of medical surveillance. However, the action level was found not to be an important trigger of medical surveillance.⁴⁹ Of the nine hospitals (9 of 82) where the 30-day action level trigger was exceeded on at least one occasion, only five hospitals provided EtO medical surveillance. Other OSHA medical surveillance triggers (pre-employment and termination examinations, EtO-related symptoms, and reproductive concerns) were not found to be significant determinants associated with the provision of EtO medical surveillance.⁵⁰

The study investigators concluded that there was low awareness on the part of hospitals about the standard's requirement to provide medical surveillance once the action level has been exceeded for 30 or more working days.⁵¹ The study investigators also documented that approximately half of the 92 sterilization department managers interviewed during the study cited difficulty in understanding OSHA EtO medical surveillance requirements as a moderate to severe barrier to providing EtO medical surveillance.

A survey of EtO medical surveillance providers was also undertaken as part of the Massachusetts Hospital EtO Health and Safety Study. This portion of the study found that nearly all of the 37 health care providers who responded to the survey provided a medical history, physical exam, and complete blood count test as part of EtO medical surveillance (as required by the EtO standard). However, the study also found that only 78% of providers (29 of 37) reported collecting the required occupational histories and only 76% (28 of 37) performed leukocyte differentials as required.⁵² (These failures to perform procedures required by the standard occurred even though many of the medical surveillance providers (20 of 34) reported that they used OSHA outreach materials as an information source for guidance in providing EtO medical surveillance.) A number of the surveyed providers (10 of 37) reported observing symptoms that were potentially related to EtO and providing medical surveillance to these workers. Most of the reports of symptoms were related to accidental EtO overexposures. Dr. LaMontagne extrapolated from these data to estimate that one or more workers at 19% of EtO using Massachusetts hospitals had experienced acute EtO-related health effects over the time period evaluated by the Massachusetts Hospital Study.

Training Findings from the Massachusetts Hospital Study

Ninety-eight percent (90 of 92) of the EtO-using hospitals in Massachusetts had provided EtO training to sterilization department workers by 1993 (regardless of whether measured occupational exposure levels would actually have required such training) [Ex. 2-9K]. The Hospital Study also found that sterilization workers were typically offered an average of 1.4 hours of EtO health and safety training per year and that there was generally good coverage of the various training topics required by the standard [Ex. 2-9K].

However, hospitals were slow in implementing the standard's training requirement. Only 58% had provided training by the end of 1985, when the requirement became effective. Another potential problem that the Hospital Study identified in these training efforts was the failure to provide training to maintenance workers exposed to EtO in the course of their work (only 54% of hospitals provided training to such workers). (OSHA notes that the standard requires the training of workers (including maintenance workers) only if they are potentially exposed to EtO at or above the EL or excursion limit.) The Hospital Study also found that many training programs did not provide complete coverage of the required medical surveillance topics during training.

The Meridian Research Report

In 1992, OSHA commissioned Meridian Research, Inc. ("Meridian") to study the effectiveness of the EtO standard. In the resulting report, "Ethylene Oxide: A Case Study in Hazard Identification, OSHA Regulation, and Market Response," Meridian used a qualitative case-study approach to evaluate how hospital sector employers responded to the technological challenges presented by the 1984 EtO standard.⁵³ This report examined exposures to EtO in the hospital sector both before and after the promulgation of the EtO standard, identified the measures implemented by hospitals to reduce employee exposures, and assessed the responses of equipment manufacturers in designing retrofit controls and new equipment to comply with the standard. As part of this study, Meridian evaluated a number of studies and other data sources (e.g., OSHA's IMIS database) that contained historical EtO exposure data and grouped the largest exposure data sets by period, concluding that there had been substantial decreases in worker exposure between the period before the promulgation of the standard (1979 to 1984) and the period following the standard (1985 to 1992). Meridian concluded, based on the available exposure data up through 1992, that in the post-1984 period, "approximately 90 percent of hospitals achieved TWAs below 1 ppm, the majority had TWAs below 0.5 ppm, and a substantial number of hospitals were achieving TWAs of 0.1 ppm."

In its report, Meridian also concluded that, within seven years after promulgation of the 1984 standard, equipment manufacturers had made significant improvements in sterilizing equipment technologies. The improved sterilizers that these manufacturers developed included built-in exposure control features (e.g., built-in aerators), unlike earlier models, which required the purchase of add-on controls to achieve compliance with the EtO standard. These improved sterilizers were also less costly than the earlier models. In 1992, sterilizers featuring built-in exposure controls were being sold at prices that were approximately half the price of older models of equipment featuring add-on engineering controls.

The Office of Technology Assessment Report

In 1995, the Congressional Office of Technology Assessment (OTA) issued a report, "Gauging Control Technology and Regulatory Impacts in Occupational Safety and Health--An Appraisal of OSHA's Analytic Approach," that included a review of the findings of OSHA's 1984 Regulatory Impact Analysis for the EtO standard.⁵⁴ OTA's review was limited to evaluating the conclusions made by OSHA with regard to the feasibility of implementing the standard in the hospital sector. In its report, OTA concluded that "OSHA's analyses for this rulemaking correctly gauged the feasibility of the tightened PEL and other compliance requirements and correctly anticipated most of the specific characteristics (engineering controls, work practice changes, and their unit costs) of the control measures implemented." OTA also indicated that "Within a year and a half after promulgation, the vast majority of hospitals were operating with ethylene oxide (EtO) exposure levels in compliance with the new PEL." However, although OTA concluded that OSHA had accurately estimated the unit costs for the control technologies that OSHA assumed the hospital sector would use, OTA found that "the sector's actual overall spending appears to have at least modestly exceeded the agency's estimate." OTA concluded that these increased costs were the result both of additional spending on modifications to existing ventilation systems not anticipated by OSHA in the 1984 Regulatory Impact Analysis and of actions taken by many hospitals to reduce exposures to a level substantially below the OSHA PEL, even though the standard did not require them to do so.

CONCLUSIONS

Data and information compiled and analyzed for this Lookback review indicate that ethylene oxide production and use has increased by about 25 percent since 1984, when the final EtO standard was issued. The number of workers estimated to be potentially exposed to EtO, however, has declined since then, falling from approximately 66,000 in 1984-1988 to about 46,000 in the mid-1990's. Most of this decline has occurred in the hospital sector, although this sector continues to have the largest EtO-exposed population (about 39,000 workers). The hospital sector also accounts for almost all of the small facilities (using the SBA's size criteria) affected by the standard. The factors principally responsible for this decline in the number of potentially exposed workers include mergers, consolidations, and firm closures in many sectors (e.g., hospitals, pharmaceuticals and chemicals), unrelated to the EtO standard, the switch to contract sterilizers rather than hospitals having some staff operating sterilizer for a small part of the day, and shifts to other sterilizing technologies (see chapter V for additional details).

Studies of the EtO standard conducted for OSHA, published in the scientific literature, and performed for the Congressional Office of Technology Assessment indicate that the standard has been successful in reducing the exposures of workers using existing control methods. In addition, OSHA's compliance experience indicates that few employers have been cited for exceeding the standard's PELs and that the technology to achieve these limits is effective and widely used. These compliance program findings provide additional evidence that the standard is technologically and economically feasible for most employers. Although some OSHA Federal and State-plan compliance personnel indicated that some small employers experience difficulty in complying with the standard's exposure monitoring and emergency alert requirements, they felt that additional compliance assistance materials, rather than revisions to the standard, would be helpful for smaller employers. (See chapter VII, Conclusions, for OSHA's responses to the comments received during this Lookback review.)

CHAPTER III
CONTINUED NEED FOR AND EFFECTIVENESS OF THE RULE

OVERVIEW

Section 610 of the Regulatory Flexibility Act requires that OSHA consider whether there is a continued need for the Ethylene Oxide standard, and Executive Order 12866 requires OSHA to determine whether, to reduce regulatory burden, the standard should be modified or eliminated. During the original rulemaking, OSHA determined that the EtO standard was needed to prevent the occurrence of adverse health effects among employees exposed to ethylene oxide and that the standard would be effective in achieving that goal. Information gathered by OSHA and comments submitted to Docket H-200C during the regulatory review process support both of these earlier determinations.

The evidence available to OSHA can be grouped into four main issues demonstrating the continued need for, and effectiveness of, the standard: (1) OSHA's original conclusions concerning the health risks of exposure to EtO have been supported by the results of new animal and epidemiological studies released since the promulgation of the standard in 1984; (2) exposure monitoring data from several sources indicate that occupational exposure to EtO has fallen markedly since the EtO standard went into effect; (3) OSHA compliance program data indicate that overexposures and accidental releases of EtO continue to occur at workplaces that are not in compliance with the standard; and (4) both employer and employee representatives indicate a continued need for the standard. OSHA has therefore concluded that the EtO standard is needed, has been effective in achieving employee protection, and should not be rescinded or revised at this time.

INFORMATION ON ADVERSE HEALTH EFFECTS AND QUANTITATIVE RISK ASSESSMENT

This section examines evidence pertaining to the adverse health effects (health hazards) and quantitative risk assessment portions of the preamble to the 1984 OSHA EtO standard and assesses whether sufficient new health-related evidence has since become available to change OSHA's conclusions about the risks associated with occupational exposure to EtO. Accordingly, the following analyses review the methodology and conclusions presented in 1984 and assess the more recent evidence on the adverse health effects from exposure to EtO.

The 1984 OSHA quantitative risk assessment procedures relied on carcinogenicity results from EtO rodent bioassays to estimate human cancer risks, since, at that time, OSHA concluded that the rodent data were the best available for risk assessment purposes. However, in the intervening years more than a half-dozen new cohort studies on occupational exposure to EtO and cancer have been published, and these human studies further support the need for the Standard. The section below provides a brief summary of the several new studies in workers.

OSHA's 1984 Risk Assessment Findings

Health Hazard Assessment

In 1984, OSHA concluded that "EtO can cause several serious adverse health effects" (49 FR 25737). These included the "suggest(ion) that EtO may cause cancer of the blood (leukemia), as well as other organs in humans. In addition, EtO exposure causes mutations, increases the rate of chromosomal aberration and sister chromatid exchange, and causes other undesirable changes in the DNA of mammalian cells....EtO exposure has also been associated with an increased risk of spontaneous abortion among pregnant women and is capable of causing other adverse reproductive effects in both men and women. Exposure to high concentrations of EtO causes central nervous system depression and other neurological effects, which are thought to be reversible with cessation of exposure. In addition, exposure to EtO gas causes sensitization and irritation of human tissues, including the eyes and respiratory tract." (49 FR 25738).

Carcinogenicity was the health effect most emphasized in the 1984 preamble, and OSHA's conclusion that EtO is a potential occupational carcinogen was based mostly on findings from long-term animal studies in different species administered EtO by different routes of exposure. Although cancers had been induced at site of first contact in oral (gavage - rat) and subcutaneous injection (mice) studies, OSHA's strongest evidence for designating EtO a potential occupational carcinogen came from positive findings of tumors in two long-term inhalation studies in rats. These studies were the Bushy Run Research Center (BRRC- Snellings, et al. 1984) study and the National Institute for Occupational Safety and Health (NIOSH - Lynch et al. 1984) study. Both studies found that EtO exposure increased tumor incidence at multiple sites; the BRRC study found increases in mononuclear cell leukemias (MCL) in female F344 rats, peritoneal mesotheliomas (PM) in male F344 rats, and brain gliomas in both sexes. The NIOSH rat inhalation study, using male F344 rats only, also found increased incidences of gliomas and PM; in addition it found increased risks of MCL. Although MCL is a common old-age tumor in this rat, gliomas are rare and PM are uncommon.

In addition to the evidence in animals, the evidence in human studies available in 1984 was based on three smaller epidemiologic studies, two (both by the same authors, Hogstedt et al. 1979a,b) of which were positive for increased leukemia mortality. In 1984, OSHA concluded, "Although OSHA believes that none of the available epidemiologic studies are in and of themselves definitive evidence of EtO's carcinogenicity, the Agency agrees that the two Hogstedt studies 'provide evidence of a possible association between occupational exposure to ethylene oxide and death from leukemia'."(49 FR 25740)

Quantitative Cancer Risk Assessment - Choice of Study, Tumor Site, Dose Metric and Dose-Response Model

In 1984, OSHA conducted a quantitative risk assessment only for carcinogenicity. The Agency's carcinogenicity risk estimates relied on data from the BRRC, using PM in male rats as the appropriate site-sex-species for animal-to-human extrapolation for risk modeling. Several reasons given for this choice related to a) the quality of the study, b) the statistical significance observed in the increase in neoplasms, c) the availability of concurrent control information, d) the fact that dose-response relationships were observed in both sexes, e) the specifics of the dosing regimen were well-documented, f) the availability of information on individual rats, and g) the fact that the study used an exposure route that was relevant to anticipated worker exposure (49 FR 25756).

OSHA concluded in 1984 that the human data were inadequate for quantitative risk assessment due to limitations in terms both of limited study size and exposure uncertainties (49 FR 25756), and that use of the MCL data in the rats was not the best choice of tumor site for animal to human extrapolation because of the high background rate of MCL in the F344 rat (49 FR 25756). Nevertheless, OSHA conducted comparison model fits and calculations for both MCL and PM.

The dose-metric used by OSHA both for animal dose-response and for the animal-to-human equivalence was mg/kg-day intake dose, where the ppm administered concentrations in the BRRC rat study were converted to mg/kg-day based on animal breathing volumes and time of animal exposure. The rat dose-response curve was fit using the rat's calculated intake doses based on the study's exposure conditions, which were 10 ppm, 30 ppm, or 100 ppm for 6-hours per day, 5 days per week over the 2-year study length (assumed to represent the rat's full life span). The lifetime risk to workers was then estimated by first calculating the human occupational intake dose on a mg/kg b.w.-day basis over an 8-hr. day, using human breathing volumes. Total intake dose was based on a 45-year occupational exposure for 46 weeks per year, and adjusted to the rat lifetime daily equivalent intake dose units. Human risk was then estimated by reading the corresponding risk from the dose-response curve in rats (49 FR 25760).

The dose-response model used to fit the BRRC data in 1984 is a version of a polynomial with parameters restricted to be non-negative; OSHA termed this the multistage model, which for these data is linear at low doses. This model provided an adequate fit to the data. OSHA used the maximum likelihood estimates of the parameters to generate its final estimates, and also provided 95% upper-limit estimates for the animal dose-response curve, which, when adjusted for human exposure conditions, were designated 95% upper-limit risk estimates for humans.

OSHA fit its multistage model to both the PM in the male rats and the MCL in the female rats. After presenting alternative estimates from other models, including a multistage-Weibull time-to-tumor model, OSHA reaffirmed the risk estimates it had presented at the time of the proposal (48 FR 17284): "OSHA predicted an excess lifetime risk for cancer from (45 year occupational) exposure to EtO at 50 ppm to be 634 to 1093 per 10,000 workers, with 95% upper confidence limits on the excess risk of 1,008 to 1,524 deaths per 10,000." (49 FR 25757). At a 1 ppm 8-hr. TWA exposure level, the estimated excess lifetime risks were "approximately 12 to 23 excess cancer deaths per 10,000 with 95% upper confidence limits of 21 to 33 excess deaths per 10,000." (49 FR 25757). OSHA chose 1 ppm as the final rule's PEL.

In 1988 OSHA amended the 1984 Final Standard to adopt an Excursion Limit (EL) of 5 ppm, averaged over a sampling period of 15 minutes (53 FR 11414-11438). The EL was not based on new health information or on information about dose-rate effects, but on OSHA's determination that such a limit was feasible and would further reduce risk under some exposure circumstances.

NEW HEALTH INFORMATION AVAILABLE SINCE THE 1984 STANDARD

Since 1984, much new information on the health effects of EtO has become available. However, the most relevant information for evaluating the appropriateness of OSHA's PELs for EtO relates to EtO's carcinogenicity. This section discusses some of that new information. For hazard identification, three areas are discussed: 1) new animal inhalation studies, 2) new human studies, 3) classification of EtO as a known human carcinogen by the International Agency for Research on Cancer (IARC, 1994), and 4) the National Toxicology Program's (NTP's) decision, in its 9th report on carcinogens, to classify EtO as a substance "known to be a human carcinogen." For quantitative risk assessment three areas are discussed: 1) choice of most appropriate animal data set, including proper animal dose-metric and proper animal-to-human species conversion, 2) choice of best human study, and 3) EPA's comments recommending that OSHA lower its PEL to 0.1 ppm. For each of these areas, pertinent comments in the Docket are also discussed.

Hazard Identification

In cancer hazard identification, three a