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The ability of five fit-test methods to screen out poorly fitting N95 filtering-facepiece respirators.
Lawrence R; Coffey C; Zhuang Z; Campbell D
American Industrial Hygiene Conference and Exposition, June 2-7, 2001, New Orleans, Louisiana. Fairfax, VA: American Industrial Hygiene Association, 2001 Jun; :69
Currently there are five fit-test methods which can be used for the fit-testing of N95 filtering-facepiece respirators. Two of these fit-test methods are qualitative (Bitrex and Saccharin) and three are quantitative (the PortaCount Plus corrected for filter penetration, the PortaCount Plus with the N95-Companion accessory (Companion), and generated aerosol). The purpose of this study was to determine the ability of each of these five fit-test methods to screen out poorly fitting N95 filtering-facepiece respirators. A panel of 25 subjects with varying face sizes tested eighteen different models of this type of respirator. The five fit tests were performed consecutively in a randomized order, with re-donning of the respirator occurring between each test. The results were compared to the 5th percentile of the simulated workplace protection factor (SWPF), an indicator of whether a respirator provided adequate protection to its wearer. The 5th percentile SWPF was determined from the total penetration (face seal leakage and filter penetration) of six tests using the PortaCount Plus, with re-donning between each test. A respirator was determined to provide adequate protection if the 5th percentile SWPF was greater than or equal to 10, the level of protection often expected for a half-mask respirator. The alpha (probability of rejecting an adequately fitting respirator) and beta (probability of accepting an inadequately fitting respirator) errors for each method were computed. The alpha error values ranged from 0.53 to 0.84 and the beta error values from 0.03 to 0.13. Based on these results, 3% of the subjects in this study passed the generated aerosol and PortaCount Plus tests with a 5th percentile SWPF of less than 10,7% with the Saccharin, 12% with the Companion, and 13% with the Bitrex tests.
Respirators; Respiratory equipment; Respiratory protective equipment; Face masks; Filters; Aerosols; Leak prevention; Personal protective equipment; Personal protection; Statistical analysis
American Industrial Hygiene Conference and Exposition, June 2-7, 2001, New Orleans, Louisiana
Page last reviewed: July 9, 2021
Content source: National Institute for Occupational Safety and Health Education and Information Division