Effect of Fit-Testing and Particle Size on the Protection Offered by N95 Filtering Facepiece Respirators Against Fine Particles in a Laboratory Setting

Details

• Personal Author:
  Grinshpun S ; Johnson E ; Lee, Stephen A. ; McKay R ; Reponen T
• Description:
  Objectives: This study investigates the effect of fit-testing and particle size on the laboratory-based protection factors (PFs) of four models of N95 filtering face piece respirators (A, B, C, and D). The challenge aerosol represented the size of naked viruses and bacteria (0.04-1.30 um). Methods: Standard respirator fit-testing was followed by particle size selective measurement of PFs while 12 subjects (3 for Respirator D) wore respirators in a test chamber. Sodium chloride particles were aerosolized using a Collison nebulizer. Particle concentration was measured inside and outside the respirator using an Electrical Low Pressure Impactor. Each respirator9subject combination was repeated three times (n = 36 for Respirators A, B, and C; n=9 for Respirator D). PF-values obtained for all tested subjects were compared to those who passed fit9testing. Results: The fit-test passing rate was 100% for Respirator A, 8% for Respirator B, 92% for respirator C, and 67% for Respirator D. About 29% of subject-respirator combinations had size-selective PF values below 10. When only subjects who passed the fit-test were included in the analysis, the PFs improved with 9% having values less than 10. On average, the geometric mean PFs over the entire particle size range were 1-4 times (29.5/21.5) higher when only data for those who passed fit-testing were included. The largest difference (21.8/10.3 = 2.1 times) between the two data sets was observed for respirator B, which had the highest fit-test failing rate. The minimum PFs were observed in the particle size range of 0.08-0.2 um for all respirator models independent of fittest status. Conclusions: Overall PFs increased, when subjects who did not pass fit-testing were excluded from analysis. The results support the value of fit-testing but also show that PFs varied by particle size regardless of fittest status. [Description provided by NIOSH]
• Subjects:
  Aerosols Occupational Health Particulate Matter Personal Protective Equipment Respiratory Protective Devices Safety
• Keywords:
  Aerosol Particles Fit Testing N95 Filtering Facepiece Respirators Particle Size Respirator Selection Respirator Testing
• Publisher:
  American Industrial Hygiene Association
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Abstract or Summary
• Place as Subject:
  Colorado ; Minnesota ; Ohio ; OSHA Region 5 ; OSHA Region 8
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  25-26
• NIOSHTIC Number:
  nn:20055116
• Citation:
  AIHce 2010: American Industrial Hygiene Conference and Exposition, May 22-27, 2010, Denver, Colorado. Falls Church, VA: American Industrial Hygiene Association, 2010 May; :25-26
• Federal Fiscal Year:
  2010
• NORA Priority Area:
  Agriculture, Forestry and Fishing
• Performing Organization:
  University of Cincinnati
• Peer Reviewed:
  False
• Start Date:
  20010601
• Source Full Name:
  AIHce 2010: American Industrial Hygiene Conference and Exposition, May 22-27, 2010, Denver, Colorado
• End Date:
  20110731
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:cec5278c44bbda97c274177a9d5a1319b0bcf54ff6a8753c48d89007788738ff693ed1d9635596fbe79783a7165c60628c59b0e14564fff890448d9a0aaaf133
• Download URL:
  https://stacks.cdc.gov/view/cdc/217483/cdc_217483_DS1.pdf
• File Type:
  [PDF - 955.57 KB ]