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Comparison of five methods for fit-testing N95 filtering-facepiece respirators - alternate approaches.

Lawrence R; Coffey C; Campbell D; Jensen P; Myers W
American Industrial Hygiene Conference and Exposition, June 1-6, 2002, San Diego, California. Fairfax, VA: American Industrial Hygiene Association, 2002 Jun; :98
A previous study had determined the ability of five fit-test methods (Bitrex, saccharin, PortaCount Plus corrected for filter penetration, PortaCount Plus/N95-Companion, and generated aerosol) to screen out poorly fitting N95 filtering-facepiece respirators. The results were compared to the 5th percentile of the simulated workplace protection factor (SWPF). No fit-test method met the American National Standards Institute (ANSI) Z88.10 standard of less than 50 percent for the alpha error (probability of rejecting an adequately fitting respirator) and less than 5 percent for the beta error (probability of accepting an inadequately fitting respirator). The correlation between the PortaCount's SWPF value and actual exposure is not one to one, but can be expressed with a quadratic equation, based on available data. The equation can be used to adjust PortaCount data to reflect this non-linearity. In this study, the original analysis was repeated using five alternatives to the 5th percentile as the reference test: (1) the mean of the SWPF, (2) the individual SWPF values, (3) the 5th percentile adjusted to account for possible bias in fit-test instrument, (4) the bias- t adjusted mean SWPF, and (5) the bias-adjust- ed individual SWPF values. With these alter- native reference tests, the range of alpha errors for the Bitrex, generated aerosol, saccharin, PortaCount Plus, and N95-Companion fit tests were, 41 to 59 percent, 67 to 86 percent, 38 to 67 percent, 51 to 79 percent, and 38 to 87 per- cent, respectively. The corresponding beta errors were 6 to 25 percent, 0 to 3 percent, 9 to 16 percent, 2 to 6 percent, and 0 to 1:9 percent, respectively. Use of the alternate methods of determining respirator performance did not result in any fit-test method meeting both error goals of the ANSI Z88.1 0 standard.
Respiration; Respirators; Filters; Filtration; Workplace-studies; Aerosols; Workplace-monitoring; Workers; Personal-protective-equipment; Protective-equipment; Respiratory-protective-equipment
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Research Tools and Approaches: Control Technology and Personal Protective Equipment
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American Industrial Hygiene Conference and Exposition, June 1-6, 2002, San Diego, California
Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division