If a qualitative respirator-fitting test has been used in respirator selection, a person shall be allowed to use only the specific make(s) and model(s) of respirator(s) for which the person obtained a satisfactory fit, and the respirator protection factor listed under "qualitative test" in Table 5 shall apply [Table C of this evaluation). Under no circumstances shall a person be allowed to use any respirator if the results of the qualitative respirator-fitting test indicate that the person is unable to obtain a satisfactory fit.[1]
In 1982, researchers at Los Alamos National Laboratory (LANL) reiterated the criteria of their organization[2] in the following statements on [Assigned] Protection Factors:
The [Assigned] Protection Factor is the number assigned to a particular type of respirator, or to an entire class of respirators, representing the degree of protection that the respirator is thought to provide for the majority of users. In the past, the (A)PF has been selected to represent the lowest level of protection provided by the class of respirators selected. The following information must be available for the derivation of a [Assigned] Protection Factor: the results of face-to-facepiece sealing tests (fit factor) on a representative number of test sub- jects, and a knowledge of the efficiency of the air-cleaning elements, if any, to be used with respi- rator in the workplace. 65 In early 1983, Myers et al. stated the definitions and measures of respirator per- formance "currently used by the NIOSH Testing and Certification Branch respirator research staff."66 They noted that "these definitions and relationships are in some instances at variance or different than those advocated by Hack, et al. [and Hyatt/LASL]" Regarding their APF definition Myers et al. stated: The "assigned protection factor is a measure of the minimum anticipated workplace level of respi- ratory protection that would be provided, by a properly functioning respirator, to a large percent- age of properly fitted and trained users. ... The assigned protection factor should be based on
65 Hack, A., C. Fairchild, and B. J. Skaggs: The Forum-Letter to the Editor, Am. Ind. Hyg. Assoc. J.
43(12):A-16. (1982).
Myers, W. R., Lenhart, S. W., Campbell, D. and G. Provost: The Forum-Letter to the Editor, Am.
Ind. Hyg. Assoc. J. 44(3):B25-26 (1983).
