Standard Interpretations - Table of Contents
• Standard Number: 1926.62

August 30, 1995

FROM:               JOHN B. MILES, JR., Director
                    Directorate of Compliance Programs

SUBJECT:            Enforcement Policy Change for Respiratory Protection
                    Required for Abrasive Blasting Under the Interim
                    Final Rule for Lead in Construction, 29 CFR 1926.62

This memorandum provides specific enforcement policy for respiratory protection required in abrasive blasting operations under the Interim Final Rule for Lead in Construction, 29 CFR 1926.62 (hereafter called the "Lead in Construction Standard"). Three points are especially important in this regard. First, the change only applies to 1926.62. Second, the change only affects enforcement actions involving the Type-CE respirators used in abrasive blasting that are manufactured by the E.D. Bullard Company, Models 77 and 88. Third, the change is an interim one, pending a final determination by OSHA of the proper protection factor to be assigned to this class of respirators.

Based upon the 1987 Respirator Decision Logic developed by the National Institute of Occupational Safety and Health ("NIOSH"), OSHA in the Lead in Construction Standard designated an APF of 25 times the permissible exposure limit ("PEL") for this Type-CE, continuous-flow, loose fitting, atmosphere-supplying, airline abrasive blast respirator (hood or helmet). With that assigned protection factor ("APF"), this type of respirator would be acceptable for use only where airborne lead concentrations are less than or equal to 25 times the PEL of 50 ug/m(3), which is 1250 ug/m(3).

In a March 29th, 1994, letter to Assistant Secretary Joseph A. Dear, the E.D. Bullard Company indicated that it believed the Agency had erred in assigning an APF as low as 25 to these two models. Bullard maintained that its respirators provide much greater protection and sought to have the APF in the Lead in Construction Standard elevated to 1000.

OSHA agreed to provide Bullard with the relief sought only if Bullard contracted with an acceptable third party to design, monitor, and interpret the results of a simulated workplace study of these models under a test protocol approved by OSHA. As a condition for granting that relief the Agency required that the results of the study demonstrate that the abrasive blast respirators achieve, at a minimum, a protection factor rating of at least 20,000 and maintain positive pressure throughout the testing.

Bullard contracted with Lawrence Livermore National Laboratory ("LLNL") which designed, conducted, and interpreted the results of the simulated workplace study based on the OSHA-approved protocol. In that test the two Bullard abrasive blast respirators achieved a minimum protection factor of 40,000 and maintained positive pressure throughout the testing.

Based upon the simulated workplace evidence, OSHA recognizes that a protection factor greater than 25 is appropriate for the Bullard abrasive blast respirators, Model 77 (TC-19C-84) and Model 88 (TC-19C-293).

The simulated workplace study carried out by LLNL indicates that, if used properly, these respirators are acceptable for exposures to lead that are less than or equal to 1000 times the PEL (50,000 ug/m(3)). However, other data and at least one field study indicate that in practice in the workplace these respirators may provide considerably less protection than indicated by the simulation study when they are used in ways that do not conform to the manufacturer's specifications (e.g., the air supply hose is too long, the hose diameter is incorrect and/or the manufacturers specified pressure is not maintained) or in ways that do not comply with the requirements of paragraphs [(c),(g),(h) and (i)] of 1910.134 (e.g., the respirator is not inspected frequently enough for possible deterioration), which are incorporated by reference in the Lead in Construction Standard, [1926.62(f)(2)(i)].

Respirators will provide less protection than they are capable of when used improperly. Examples of improper respirator usage include the donning and doffing of respirators while still in containment or disconnecting the air hose prior to leaving the exposure area. What is unusual in connection with these respirators is the extreme conditions under which they may be used in construction activities. Typically, abrasive blast respirators are used at very high levels of exposure (e.g., in the thousands of or tens of thousands of ug/m(3) and are subject to substantial and at times rapid deterioration due to damage caused by the high-speed, abrasive material used in the blasting. Also, at times these respirators will be used near the limits of their protective capability. Consequently, workers wearing these respirators in abrasive blasting operations may be subjected to acute toxic exposures if the respirators do not perform properly. It is imperative, therefore, that these respirators be properly used. Per