Electrostatic N-95 Respirator Filter Media Efficiency Degradation Resulting from Intermittent Sodium Chloride Aerosol Exposure

Details

• Personal Author:
  Bergman MS ; Moyer, Ernest S.
• Description:
  The effects of intermittently loading small masses of sodium chloride aerosol on the filtration efficiency of N-95 filtering facepiece respirators was investigated. The National Institute for Occupational Safety and Health (NIOSH) certifies that N-95 respirators must provide at least 95 percent filtration efficiency against a sodium chloride aerosol challenge as per the respirator certification (42 CFR 84) test criteria. N-95 respirators are specified for protection against solid and water-based particulates (i.e., non-oil aerosols). New N-95 respirators from three different manufacturers were loaded with 5-1 mg of sodium chloride aerosol one day a week, over a period of weeks. Aerosol loading and penetration measurements were performed using the TSI 8130 Filter Tester. Respirators were stored uncovered on an office desktop outside the laboratory. To investigate environmental and temporal effects of filters being stored without sodium chloride exposure, control respirators were stored on the desk for various lengths of time before being initiated into weekly testing. For all manufacturers' respirators, the controls showed similar initial penetrations on their day of initiation (day zero) to those of the study samples on day zero. As the controls were tested weekly, they showed similar degradation rates to those of the study samples. Results show that some of the manufacturers' models had penetrations of greater than 5 percent when intermittently exposed to sodium chloride aerosol. It is concluded that intermittent, low-level sodium chloride aerosol loading of N-95 respirators has a degrading effect on filter efficiency. This reduction in filter efficiency was not accompanied by a significant increase in breathing resistance that would signal the user that the filter needs to be replaced. Furthermore, it was noted that the effect of room storage time prior to initial exposure was much less significant. [Description provided by NIOSH]
• Subjects:
  Aerosols Occupational Health Respiratory Protective Devices Respiratory System Safety
• Keywords:
  Aerosol Particles Aerosol Sampling Author Keywords: Respirators Filter Efficiency Filter Efficiency Degradation Filters Respirators Respiratory Equipment Respiratory Protection Respiratory Protective Equipment Sodium Chloride Aerosol

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• ISSN:
  1047-322X
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  OSHA Region 3 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  DRDS - Division of Respiratory Disease Studies
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  15
• Issue:
  8
• NIOSHTIC Number:
  nn:20020762
• Citation:
  Appl Occup Environ Hyg 2000 Aug; 15(8):600-608
• Contact Point Address:
  Ernest S. Moyer, National Institute for Occupational Safety and Health, Division of Respiratory Disease Studies, Morgantown, West Virginia
• Federal Fiscal Year:
  2000
• Peer Reviewed:
  True
• Source Full Name:
  Applied Occupational and Environmental Hygiene
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:feb9fde636912dfb27eff97b7a3a2dc33f438dc29bfab8bfcda2e4842c656e9c1f3a049fa45b8b24382506c0b615482dc38bea35010e191afec82e5730885951
• Download URL:
  https://stacks.cdc.gov/view/cdc/198430/cdc_198430_DS1.pdf
• File Type:
  [PDF - 411.50 KB ]