Filter efficiency degradation in N95 respirators caused by sodium chloride aerosol

Details

• Personal Author:
  Bergman MS ; Moyer, Ernest S.
• Description:
  The National Institute for Occupational Safety and Health (NIOSH) investigated effects of periodically loading small masses of sodium chloride (NaCl) aerosol on the filtration efficiency of N95 filtering facepiece respirators. NIOSH certifies that N95 respirators must provide at least 95% filtration efficiency as per the 42 CFR 84 test criteria. N95 respirators are specified for protection against solid and water-based particulates (i.e., nonoil aerosols). New N95 respirators from three different manufacturers were loaded with 5 + / - 1 mg NaCl aerosol 1 day a week, over a period of 17 weeks. Aerosol loading and penetration measurements were performed using the TSI 8130 Filter Tester. Respirators were stored uncovered on an office desktop outside of the laboratory. To investigate environmental and temporal effects of filters being stored without NaCl 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 to those of the study samples on day 1. 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% when exposed to intermittent NaCl aerosol loads. This data suggests that service time recommendations should account for efficiency degradation with intermittent, low-level loading of NaCl aerosol. It is concluded that periodic loading of small masses of NaCl aerosol onto N95 respirators has a significant degrading effect on filter efficiency. Furthermore, it is noted that effects of storage time and storage atmosphere in this study are much less significant. [Description provided by NIOSH]
• Subjects:
  Aerosols Chlorine Environmental Health Filtration Laboratories Manufacturing And Industrial Facilities Occupational Health Personal Protective Equipment Respiratory Protective Devices Respiratory System Safety

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• Keywords:
  Aerosol-particles Air-purifying-respirators Chlorides Environmental-factors Equipment-reliability Face-masks Filters Laboratory-testing Materials-storage Performance-capability Personal-protective-equipment Respirators Respiratory-equipment Sodium-compounds Testing-equipment

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• Publisher:
  American Industrial Hygiene Association
• Document Type:
  Text
• Genre:
  Abstract or Summary
• Place as Subject:
  Georgia ; OSHA Region 3 ; OSHA Region 4 ; 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
• Pages in Document:
  61
• NIOSHTIC Number:
  nn:20043991
• Citation:
  American Industrial Hygiene Conference and Exposition, May 9-15, 1998, Atlanta, Georgia. Fairfax, VA: American Industrial Hygiene Association, 1998 May; :61
• CAS Registry Number:
  Sodium chloride (CAS RN 7647-14-5)
• Federal Fiscal Year:
  1998
• Peer Reviewed:
  False
• Source Full Name:
  American Industrial Hygiene Conference and Exposition, May 9-15, 1998, Atlanta, Georgia
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:c2c71569b3a7d9b595f7cebb9b4d179ead99976339bdc8b293738095bdb3bf8e2c40747c0f45e564dfb3ee827b40f9704cc1e60f647e8f4c8008fb6b27837819
• Download URL:
  https://stacks.cdc.gov/view/cdc/199848/cdc_199848_DS1.pdf
• File Type:
  [PDF - 634.19 KB ]