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.

May 30, 2002



SUBJECT: Enforcement Policy Change for Respiratory Protection For Select Respirators for Use in the Pharmaceutical Industry


This memorandum provides specific enforcement policy for respirator use in the Pharmaceutical Industry (SICs 2833 and 2834). Three points are especially important in this regard. First, the change only applies to the protection from particulates in the pharmaceutical industry. Second, the change only affects the nine respirators listed below. Third, the change is an interim change only, pending a final determination by OSHA of the proper protection factor to be assigned to these classes of respirators as part of the current respiratory protection standard rulemaking of 29 CFR 1910.134.

Based upon the 1987 Respirator Decision Logic developed by the National Institute for Occupational Safety and Health (NIOSH), an Assigned Protection Factor (APF) of 25 for continuous-flow, loose fitting respirators (hood or helmet) has been enforced by OSHA. In January 1998, OSHA revised its respiratory protection standard, but reserved modifications to the APFs for future rulemaking.

In 1996, during the respirator rulemaking process, the pharmaceutical industry members of Organization Resources Counselors, Inc. (ORC) approached OSHA about their need for a respirator with a higher protection factor to protect against biologically active compounds that pose a risk at orders of magnitude below aerosol levels typically found in OSHA PELs. ORC contracted with Lawrence Livermore National Laboratory (LLNL) to design, conduct, and interpret the results of a simulated workplace study. The study tested both Supplied Air Respirators (SARs) and Powered Air Purifying Respirators (PAPRs) against an airborne particulate. In that test most of the respirators achieved a minimum protection factor of 10,000 and maintained positive pressure inside the respirator throughout the testing.

The simulated workplace study carried out by LLNL incorporated work procedures and body positions normally encountered by employees in the pharmaceutical industry. The study indicated that, if used properly and when equipped with the accessories mentioned below, these respirators are generally acceptable for exposures to particulates that are less than or equal to 1000 times their respective PELs. However, other studies have also indicated that in practice in the workplace, respirators may provide considerably less protection than indicated by a 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 manufacturer's specified pressure is not maintained) or in workplace situations where the requirements of 1910.134 are not being met.

Based upon the simulated workplace evidence, OSHA recognizes that a protection factor greater than 25 is appropriate for these respirators when used and equipped as tested. The following respirators (with the accessories indicated) will be treated by OSHA as if they had an APF of 1000 for use in the pharmaceutical industry for protection against particulates:

Powered-Air Purifying Respirators (PAPRs)



  • 3M Whitecap helmet (TC-21C-670) with chinstrap and GVP-100 blower (hard plastic helmet with bib)
  • 3M Snapcap hood (TC-21C-671) with chinstrap and GVP-100 blower (Tyvek hood with bib)
  • 3M (formerly Racal) BE-5 (TC-21C-277) (clear PVC hood with bib)
  • 3M (formerly Racal) BE-10 (TC-21C-480) (polycoated Tyvek hood with bib and head suspension)

Supplied-Air Respirators (SARs)

  • 3M Whitecap helmet(TC-19C-069) with chinstrap (hard plastic helmet with bib)
  • 3M Snapcap hood (TC-19C-069) with chinstrap (Tyvek hood with bib)
  • MSA VERSA-Hood (TC-19C-224) with #5-613-1 direct hose connection for 3/8" hose system (Tyvek hood)
  • North Model 85301 TB (TC-19C-350) (Tyvek hood with ratchet head suspension and bib)
  • Bullard CC 20TIC (TC-19C-154, Type C) with 20 RT suspension and 20 NC nylon chinstrap (Tyvek hood with bib).

These respirators will only be considered to have an APF of 1000 when used properly. For example, most have bibs which must be tucked into outer clothing to ensure proper protection. Improper respirator use also includes the donning and doffing of respirators while still in containment areas or disconnecting the air hose prior to leaving the exposure area. Workers wearing these respirators may be subjected to acute toxic exposures if the respirators do not perform properly. It is imperative, therefore, that these respirators be properly used; protection consonant with the interim assigned protection factor can only be assured when they are properly used.

For these reasons, employers must ensure that these respirators are used only in accordance with the manufacturer's specifications, that the respirator is functioning properly, that the users are properly fitted and trained, and that the employer has implemented a continuing, effective respiratory protection program as specified by 29 CFR 1910.134. Documented deficiencies related to the respirator or the respiratory protection program should be cited.

If you should have any further questions concerning this matter, please feel free to contact the [Office of Health Enforcement] at (202) 693-2190.