title: Effect of upper strap downward displacement on n95 filtering facepiece respirator fit factors: a pilot study.
abstract: Fifteen subjects underwent three replicates of quantitative respirator fit-testing with N95 filtering facepiece respirators that were donned with the upper strap high on the occiput, as per the manufacturers' donning instructions. Each fit-test was immediately followed by repeat fit-testing with the upper strap downwardly displaced to the level of the ear sulcus to determine any change in fit factors that might occur with upper strap downward slippage. A total of 35/45 (78%) initial fit-tests had a passing score (fit factor ≥ 100) with the top strap high on the occiput and 33/35 (94%) of these passed subsequent fit-testing after the top strap was displaced downward to the ear sulcus. Geometric mean fit factors for the initial passed fit-tests, and following downward strap displacement, were 217 ± 1.6 and 207 ± 1.9, respectively (p = 0.64). Downward displacement of the top strap did not significantly impact fit factors of N95 FFRs that had previously passed fit-testing.
authors.affiliation: a National Personal Protective Technology Laboratory, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention , Pittsburgh , Pennsylvania.
authors.forename: Raymond J
authors.initials: RJ
authors.lastname: Roberge
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Palmiero
authors.forename: Yuewei
authors.initials: Y
authors.lastname: Liu
authors.forename: Jung-Hyun
authors.initials: JH
authors.lastname: Kim
authors.forename: Ziqing
authors.initials: Z
authors.lastname: Zhuang
mesh_terms: D000328:Adult; D004868:Equipment Failure; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure / Q000517:prevention & control*; D010865:Pilot Projects; D012134:Respiratory Protective Devices / Q000592:standards*
keywords: N95 filtering facepiece respirators; displacement; fit factors; top strap