title: Impact of multiple consecutive donnings on filtering facepiece respirator fit.
abstract: BACKGROUND
  A concern with reuse of National Institute for Occupational Safety and Health-certified N95 filtering facepiece respirators (FFRs) is that multiple donnings could stress FFR components, impairing fit. This study investigated the impact of multiple donnings on the facepiece fit of 6 N95 FFR models using a group of 10 experienced test subjects per model.
  
  
  METHODS
  The TSI PORTACOUNT Plus and N95 Companion accessory were used for all tests. After qualifying by passing a standard Occupational Safety and Health Administration fit test, subjects performed up to 20 consecutive tests on an individual FFR sample using a modified protocol. Regression analyses were performed for the percentage of donnings resulting in fit factors (FFs) ≥100 for all 6 FFR models combined.
  
  
  RESULTS
  Regression analyses showed statistical significance for donning groups 1-10, 1-15, and 1-20. The mean percentage of donnings with an FF ≥100 was 81%-93% for donning group 1-5, but dropped to 53%-75% for donning group 16-20.
  
  
  CONCLUSIONS
  Our results show that multiple donnings had a model-dependent impact on fit for the 6 N95 models evaluated. The data suggest that 5 consecutive donnings can be performed before FFs consistently drop below 100.
authors.affiliation: URS Corporation, Pittsburgh, PA, USA.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Bergman
authors.forename: Dennis J
authors.initials: DJ
authors.lastname: Viscusi
authors.forename: Ziqing
authors.initials: Z
authors.lastname: Zhuang
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Palmiero
authors.forename: Jeffrey B
authors.initials: JB
authors.lastname: Powell
authors.forename: Ronald E
authors.initials: RE
authors.lastname: Shaffer
mesh_terms: D019544:Equipment Failure Analysis; D017743:Equipment Reuse / Q000706:statistics & numerical data*; D005260:Female; D005374:Filtration; D006801:Humans; D008297:Male; D016273:Occupational Exposure / Q000517:prevention & control*; D016272:Occupational Health; D012134:Respiratory Protective Devices