6—Review and evaluation of professional practices used during the 1970s and 1980s for respirator face-seal evaluations and APF determinations.
As part of its efforts to develop APF values as part of this evaluation, NIOSH reviewed and evaluated professional practices used during the 1970s and 1980s for respirator face-seal performance evaluations and APF determinations. All NIOSH conclusions stated in this section are based on the best available evidence regarding professional practices used during these two decades.
The concept of respirator-class protection factors is over 25 years old. Since the early 1980s they have been called assigned protection factors (APFs) by respirator specialists. Hyatt[1] noted in 1976 that the first official definition of the term
[assigned] protection factor was made by the U. S. Bureau of Mines in their Approval
Schedule 21B published in 1965.43 For over 7 years from 1965 to 1972, assigned
protection factors were part of filter-type respirator certifications issued by the Bu-
reau of Mines. Hyatt also reported that two years later in 1967, the Atomic Energy
Commission (AEC) Director of Regulation published proposed [assigned] protection
factors." Hyatt reported that due to concerns relative to the lack of adequate test
data for all types of devices, the AEC-proposed (assigned) protection factor table was
withdrawn.
It is important to recognize that most current respirator-class APFs are founded on
the professional precepts, technical policies, and respirator protection factor val-
ues 15 developed during the late 1960s through the 1970s as the product of AEC-fund-
"JU. S. Department of the Interior, Bureau of Mines: Respiratory Protective Apparatus-Tests for Permissibility; Fees: Schedule 21B, Filter-Type Dust, Fume, and Mist Respirators (30 CFR Part 14), Federal Register 30(#616), (January 19, 1965) as amended at 34 FR 9617 (June 12, 1969). "U. S. Atomic Energy Commission: Proposed Rule Making, Standards for Protection Against Radia tion-10 CFR Part 20, Federal Register 32(#215), (November 4, 1967). 45Hyatt E.C.: Respirator Protection Factors. Los Alamos Scientific Laboratory, Informal Report No.
LA-6084-MS (1976), Table 1, pp. 4–5.
- ↑ Hyatt E.C.: Respirator Protection Factors. Los Alamos Scientific Laboratory, Informal Report No. LA-6084-MS (1976), p. 7.
