OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at https://www.osha.gov.

July 11, 1988

Ms. Sara D. Schotland
Cleary, Gottlieb, Steen and Hamilton
752 N Street, N.W.
Washington, D.C. 20036

Dear Ms. Schotland:

This is a follow-up to the meetings and telephone calls held between you and members of my staff regarding your request for written clarification of the occupational Safety and Health Administration's (OSHA) position on the use of respirators while unloading ethylene oxide (EtO) sterilization chambers.

During the April 29 meeting you attended with OSHA officials as the Health Industry Manufacturer's Association (HIMA) representative, you requested OSHA to exempt certain ethylene oxide sterilizer unloading operations from meeting the excursion limit of 5 ppm EtO for 15 minutes through the utilization of engineering and work practices controls, as required by the OSHA standard at 29 CFR 1910.1047. You provided a draft compliance directive to the attendees which set forth the criteria HIMA felt should be disseminated to OSHA field staff, for their use in "establishing infeasibility of compliance through engineering and work practice controls" during their inspection of facilities where EtO sterilizers are in operation.

OSHA feels the concerns you have raised have been specifically addressed in the preamble to the final standard for occupational exposure to ethylene oxide. The standard, at FR, Vol. 53, No. 66, states that "while OSHA recognizes some potential for infeasibility in some operations, the Agency does not believe that it justifies a blanket finding of infeasibility for "sterilizer unloading" per se. The preamble contains a lengthy discussion of the Agency's recognition of the uniqueness of EtO exposures found in sterilization operations.

The preamble further states: "OSHA has evaluated HIMA's submittals and acknowledges that there may be some limited situations involving employee entry into large industrial sterilizers, under conditions of full capacity utilization and continuous sterilization cycles in which there may not be adequate time for offgassing of the sterilized materials in the sterilizer before employees are exposed. In these situations, as is the case with the current 1 ppm TWA, employees would need to be protected by respirators during their entry into and exit form the sterilizer. However, based on its review of the record including Meridian's site visits, OSHA does not believe that a general exclusion of "sterilizer unloading" is warranted. The Agency has determined that for most sterilizer unloading, a combination of engineering controls and work practices will enable employers to comply with the 5 ppm excursion limit."

Agency policy is that engineering controls are preferred over respiratory protection. Whenever the feasible engineering and work practices controls are not sufficient to reduce employee exposure to or below the excursion limit, they must nonetheless be instituted by the employer to reduce employee exposure to the lowest levels achievable and then be supplemented by the use of respiratory protective equipment. Work practice controls may include change in work schedules to extend the amount of time spent in offgassing of sterilized product. Employers in sterilizer operations, therefore, have the responsibility to install all feasible engineering and work practice controls to reduce employee exposures to the lowest levels achievable; and, if levels of EtO are still not below the PELs, they must then supplement these controls with employee respiratory protection. Although OSHA cannot tell our enforcement staff in advance when it is infeasible to control exposures completely through engineering and work practice controls, the Agency does recognize that such situations can arise in specific workplace conditions. Where the controls installed can be shown by the employer, on a case-by-case basis, to be infeasible to achieve the excursion limit, the employer may then achieve compliance with the use of respiratory protection.

We hope this letter clarifies OSHA's position. Should you have any more concerns, please feel free to contact me or my staff again.

Sincerely,



Thomas J. Shepich, Director