Performance of eighteen N95 filtering-facepiece models.
Coffey C; Lawrence R; Campbell D; Jensen P; Zhuang Z
American Industrial Hygiene Conference and Exposition, June 1-6, 2002, San Diego, California. Fairfax, VA: American Industrial Hygiene Association, 2002 Jun; :46
A panel of 25 subjects with varying face sizes tested 18 models of N95 filtering face- piece respirators. The performance of the respirators was determined with and without fit-testing using the 5th percentile simulated workplace protection factor (SWPF) tests determined from the total penetration (face seal leakage plus filter penetration) of six tests using the PortaCount Plus with redonning occurring between each test. The fit-tests used were: Bitrex, saccharin, generated aerosol, PortaCount Plus corrected for filter penetration, and the PortaCount Plus with the N95 Companion accessory. The 5th percentile SWPF for all models combined without fit- testing was 3.0. The 5th percentile SWPF without fit-testing for the individual models ranged from 1.3 to 48.0. Passing a fit-test resulted in the following 5th percentile SWPFs: saccharin - 2.0 to 8.1; Bitrex - 2.2 to 23.3; PortaCount -1.4 to 33.0; N95 Companion - 85.1 to 122; and generated aerosol - 2.9 to 34.6. To further describe the fitting characteristics of these respirators, the h-value (the fraction of a population who will obtain an adequate fit when a respirator is selected, donned, and fit-checked in accordance with the manufacturer's instructions before fit-testing) was computed. A donning was determined to have an adequate fit if the SWPF was 310. The h- value for all models combined was 0.74 (74% of all donnings resulted in a SWPF of at least 10). The h-values for the individual models ranged from 0.50 to 0.99 with only 3 of the 18 models achieving 95% or more of the donnings with a SWPF of at least 10. This study demonstrates that although fit-testing can be used to increase the protection provided by N95 respirators, fit-test alone is not sufficient to assure protection factors of 10 or greater. It is also necessary to utilize respirator models with good fitting characteristics (i.e., high h- values).
Respirators; Models; Workplace-studies; Filter-materials; Filters; Filtration
Research Tools and Approaches: Control Technology and Personal Protective Equipment
American Industrial Hygiene Conference and Exposition, June 1-6, 2002, San Diego, California