Section 1910.134(b)(8) of the previous standard required that only those respirators approved jointly by NIOSH and MSHA be used by the employer. The current respirator testing and approval regulation, 30 CFR 11, which authorized the Bureau of Mines and NIOSH to jointly approve respiratory protection devices, was promulgated on March 25, 1972 at 37 FR 6244. On November 5, 1974 the Mine Enforcement Safety Administration (MESA) succeeded the Bureau of Mines and joined NIOSH in jointly approving respirators. Following the transfer of MESA to the Department of Labor, where it became the Mine Safety and Health Administration (MSHA), authority was transferred on March 24, 1978 to MSHA for joint approval with NIOSH of respirators. Most of the Bureau's respiratory testing methods, developed in the 1950s or earlier, were changed in the 1970s to reflect changes in testing technology.

NIOSH initiated revision of 30 CFR 11 in 1980. A public meeting was held in July 1980 to address the certification program. On August 27, 1987, NIOSH published a notice of proposed rulemaking (52 FR 32402) that would have allowed NIOSH to certify respirators under the new 42 CFR part 84 regulations, replacing the current joint NIOSH/MSHA 30 CFR 11 certification regulations. The proposed NIOSH certification regulations contained new and revised requirements for testing and certification of respirators, and included a set of assigned protection factors for various classes of respirators. Public hearings on the first draft of the NIOSH proposal were held in January 1988. On the basis of the comments received, NIOSH prepared a revised proposal for further public comment. On June 8, 1995 NIOSH published revised respirator certification procedures for particulate respirators (60 FR 30336) and recodified the previous certification standards for the other respirator classes as 42 CFR Part 84. These certification procedures address N, P and R class particulate respirators at 95%, 99%, and 99.7% levels of effectiveness. Additional public comment was sought at public meetings convened in June 1996 to assist NIOSH in preparation of future rulemakings that will continue the revision of the certification procedures for other classes of respirators. In October 1997, NIOSH announced the intended priority order for these future rulemakings. Relevant aspects of these proceedings are discussed in the Summary and Explanation.