Method for Measuring the Spatial Variability of Aerosol Penetration Through Respirator Filters

Details

• Personal Author:
  Grinshpun S ; Huang C ; Qian Y ; Ulevicius V ; Willeke K ; Grinshpun S ; Huang C ; Qian Y ; Ulevicius V ; Willeke K
• Description:
  Fibrous filter media are widely used in respirators to remove airborne particulate matter from the inhaled airflow of workers. The N95 half-mask particulate respirator appears to be the most frequently used respirator under the new NIOSH regulation, 42 CFR 84. Considerable spatial variability in light penetration through the fibrous filter medium of an N95 respirator can be seen by visual observation when it is held to the light. This variability is due to the way in which the fibers are manufactured and laid down to form the filter medium. Similar spatial variability is expected in the aerosol penetration through the filters. Therefore, a test method has been developed for measuring the spatial variability in aerosol penetration. The main components of this method are an aerosol generator, a filter test stand with a movable sampling inlet, an aerosol size spectrometer, and an aerosol photometer. Measurements with the filter media of N95 respirators, tested at average filtration velocities corresponding to light, moderate, and heavy work loads, have shown spatial variations in aerosol penetration in excess of 100% relative to the average aerosol penetration for the entire respirator. N95 respirators are required to be at least 95% efficient (i.e., less than 5% penetrating) at the most penetrating particle size, when tested at 85 L/min. Tests with the new method have shown that the aerosol penetration of the most penetrating particles of about 0.1 micron diameter may locally be higher than 5%, while the average aerosol penetration of 0.1 micron particles is less than 5%. [Description provided by NIOSH]
• Subjects:
  Aerosols Air Movements Air Pollutants, Occupational Filtration Occupational Health Particulate Matter Personal Protective Equipment Respiratory Protective Devices Respiratory System Safety
• Keywords:
  Aerosol-particles Air-filters Air-flow Airborne-particles Author Keywords: Aerosol Penetration Filter Medium Filters Personal-protection Personal-protective-equipment Respiration Respirator Respirators Respiratory-protection Respiratory-protective-equipment Spatial Variability

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• ISSN:
  0002-8894
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article ; Journal Article
• Place as Subject:
  Ohio ; OSHA Region 5
• CIO:
  National Institute for Occupational Safety and Health (NIOSH) ; National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health ; Workplace Safety & Health
• Location:
  North America ; North America
• Pages in Document:
  461-465
• Volume:
  59
• Issue:
  7
• NIOSHTIC Number:
  nn:20030556
• Citation:
  Am Ind Hyg Assoc J 1998 Jul; 59(7):461-465
• Federal Fiscal Year:
  1998
• Performing Organization:
  University of Cincinnati, Cincinnati, Ohio
• Peer Reviewed:
  True
• Start Date:
  19950201
• Source Full Name:
  American Industrial Hygiene Association Journal
• End Date:
  19980731
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:a0308aa034d84eb0f873ca74db65ff26d611851005917d139c267de5397378fa90ce0dd642fff8fc4fd149e0b20c58901371cc49d1ffc1dcb1048de2a478797f
• Download URL:
  https://stacks.cdc.gov/view/cdc/191119/cdc_191119_DS1.pdf
• File Type:
  [PDF - 136.82 KB ]