N95 filtering facepiece respirator deadspace temperature and humidity

Details

• Personal Author:
  Benson S ; Kim J-H ; Roberge RJ
• Description:
  The objective of this study was to determine the levels of heat and humidity that develop within the deadspace of N95 filtering facepiece respirators (N95 FFR). Seventeen subjects wore two models each of N95 FFR and N95 FFR with an exhalation valve (N95 FFR/EV) while exercising on a treadmill at a low-moderate work rate for 1 and 2 hr in a temperate ambient environment. FFR deadspace temperature and relative humidity were monitored by a wireless sensor housed within the FFR. Each FFR was weighed pre- and post-testing to determine moisture retention. After 1 hr, FFR deadspace temperature and humidity were markedly elevated above ambient levels, and the FFR deadspace mean apparent heat index was 54 degree C. N95 FFR/EV use resulted in significantly lower deadspace temperatures than N95 FFR (p = 0.01), but FFR deadspace humidity levels were not significantly different (p = 0.32). Compared with the first hour of use, no significant increase in FFR deadspace heat and humidity occurred over the second hour. FFR mean moisture retention was < 0.3 grams over 2 hr. N95 FFR/EV offer a significant advantage in deadspace heat dissipation over N95 FFR at a low-moderate work rate over 1 hr of continuous use but offered no additional benefit in humidity amelioration. Moisture retention in N95 FFR and N95 FFR/EV is minimal after 2 hr of use. [Supplementary materials are available for this article. Go to the publisher's online edition of Journal of Occupational and Environmental Hygiene for the following free supplemental resource: a file containing N95 filtering facepiece respirator deadspace mean RH and temperature recordings for 17 subjects treadmill exercising at 5.6 Km/H over 1 hour.] [Description provided by NIOSH]
• Subjects:
  Filtration Hot Temperature Humidity Occupational Health Personal Protective Equipment Respiratory Protective Devices Respiratory System Safety Temperature
• Keywords:
  Author Keywords: Deadspace Equipment-design Equipment-reliability Exhalation Valve Face-masks Filters Heat N95 Filtering Facepiece Respirators Personal-protective-equipment Relative-humidity Respirators Respiratory-equipment Respiratory-protective-equipment Temperature Temperature-effects Testing-equipment

  More +
• ISSN:
  1545-9624
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  OSHA Region 3 ; Pennsylvania
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  NPPTL - National Personal Protective Technology Laboratory
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  166-171
• Volume:
  9
• Issue:
  3
• NIOSHTIC Number:
  nn:20040491
• Citation:
  J Occup Environ Hyg 2012 Mar; 9(3):166-171
• Contact Point Address:
  Raymond J. Roberge, NIOSH-NPPTL, 626 Cochrans Mill Road, Pittsburgh, PA 15236
• Email:
  dtn0@cdc.gov
• Federal Fiscal Year:
  2012
• NORA Priority Area:
  Healthcare and Social Assistance
• Peer Reviewed:
  True
• Source Full Name:
  Journal of Occupational and Environmental Hygiene
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:af9b569e53ba5a8331998ccdbe616b2810e8ef48478bf8c33000a31560ef733b94c290e0d7d2fbd6a2ebe88514031ee7396474a210a0783af0d79011fdd31b3f
• Download URL:
  https://stacks.cdc.gov/view/cdc/193328/cdc_193328_DS1.pdf
• File Type:
  [PDF - 290.62 KB ]