Simulated workplace performance of N95 respirators.
American Industrial Hygiene Conference and Exposition, May 9-15, 1998, Atlanta, Georgia. Fairfax, VA: American Industrial Hygiene Association, 1998 May; :61
The National Institute for Occupational Safety and Health (NIOSH) has received many inquiries about the face-fitting characteristics of the new N95 respirators. These inquiries raised the issues of how well do these respirators fit, whether N95 respirators have to be fit-tested, and whether they can be quantitatively fit-tested. In response, researchers of the NIOSH Certification and Quality Assurance Branch evaluated the performance of 12 N95 respirator models on a panel of 25 subjects with varying face sizes. The performance of each respirator model was assessed in two ways: first, on the panel of 25 subjects not fit-tested and, second, after removing from the panel those subjects failing a fit test. Total penetration, the combination of filter penetration and face seal leakage, was measured for each panel member. The 95th-percentile of the total penetration values was then computed for each model. The 95th-percentile of the total penetration that is typically used to indicate overall respirator performance indicates that 95% of the wearers can expect to have a total respirator penetration less than this value. The 95th-percentile total penetration without fit-testing for the 12 respirators ranged from 5 to 77%. A properly fitted half-mask respirator is expected to have a total penetration less than 10%. When the first donning was used as a surrogate fit-test to screen out poor fits, the 95th-percentile of the total penetration decreased to 2 to 4%, a significant increase in protection. Therefore, this study suggests that this level of protection is achieved only when fit-testing is performed to screen out poor face fits. The results also indicate that fit-testing is an essential element of a respirator program. Without fit-testing, the protection provided by this class of respirator is unreliable.
Respirators; Respiratory-equipment; Face-masks; Air-purifying-respirators; Anthropometry; Personal-protective-equipment; Performance-capability; Testing-equipment; Humans; Analytical-models; Models; Equipment-reliability; Leak-prevention
American Industrial Hygiene Conference and Exposition, May 9-15, 1998, Atlanta, Georgia