What does respirator certification tell us about filtration of ultrafine particles?
Recent interest in exposures to ultrafine particles (less than 100 nm) in both environmental and occupational settings led the authors to question whether the protocols used to certify respirator filters provide adequate attention to ultrafine aerosols. The authors reviewed the particle size distrib...
| Publicado en: | Journal of Occupational & Environmental Hygiene Vol. 5; no. 5; pp. 286 - 296 |
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| Autores principales: | , , , , |
| Formato: | Journal Article |
| Publicado: |
Taylor & Francis Ltd
May2008
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| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=105905639&site=ehost-live header: @attributes: shortDbName: ccm uiTerm: 105905639 longDbName: CINAHL Complete uiTag: AN controlInfo: bkinfo: dissinfo: jinfo: jid: 15459624 V1L jtl: Journal of Occupational & Environmental Hygiene issn: 15459624 maglogo: Y pubinfo: dt: May2008 vid: 5 iid: 5 pid: 377 pub: Taylor & Francis Ltd place: Philadelphia, Pennsylvania artinfo: ui: 105905639 105905639 2009879666 10.1080/15459620801960153 NLM18322869 105905639 ppf: 286 ppct: 10 formats: fmt: @attributes: type: P tig: atl: What does respirator certification tell us about filtration of ultrafine particles? aug: au: Eninger RM Honda T Reponen T McKay R Grinshpun SA affil: Department of Environmental Health, University of Cincinnati, Cincinnati, Ohio. sug: subj: Aerosols Air Pollutants, Occupational Environmental Monitoring Occupational Exposure Particle Size National Institute for Occupational Safety and Health ab: Recent interest in exposures to ultrafine particles (less than 100 nm) in both environmental and occupational settings led the authors to question whether the protocols used to certify respirator filters provide adequate attention to ultrafine aerosols. The authors reviewed the particle size distribution of challenge aerosols and evaluated the aerosol measurement method currently employed in the National Institute for Occupational Safety and Health (NIOSH) particulate respirator certification protocol for its ability to measure the contribution of ultrafine particles to filter penetration. Also considered were the differences between mechanical and electrically charged (electret) filters in light of the most penetrating particle size. It was found that the sodium chloride (NaCl) and dioctylphthalate (DOP) aerosols currently used in respirator certification tests contain a significant fraction of particles in the ultrafine region. However, the photometric method deployed in the certification test is not capable of adequately measuring light scatter of particles below approximately 100 nm in diameter. Specifically, 68% (by count) and 8% (by mass) of the challenge NaCl aerosol particles and 10% (by count) and 0.3% (by mass) of the DOP particles below 100 nm do not significantly contribute to the filter penetration measurement. In addition, the most penetrating particle size for electret filters likely occurs at 100 nm or less under test conditions similar to those used in filter certification. The authors conclude, therefore, that the existing NIOSH certification protocol may not represent a worst-case assessment for electret filters because it has limited ability to determine the contribution of ultrafine aerosols, which include the most penetrating particle size for electret filters. Possible strategies to assess ultrafine particle penetration in the certification protocol are discussed. pubtype: Academic Journal doctype: Journal Article ougenre: Article language: English refInfo: holdings: @attributes: islocal: N |
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