Particle loading time and humidity effects on the efficiency of an N95 filtering facepiece respirator model under constant and inhalation cyclic flows

The Annals of Occupational Hygiene
Alireza MahdaviClaude Ostiguy

Abstract

It is necessary to investigate the efficiencies of filtering facepiece respirators (FFRs) exposed to ultrafine particles (UFPs) for long periods of time, since the particle loading time may potentially affect the efficiency of FFRs. This article aims to investigate the filtration efficiency for a model of electrostatic N95 FFRs with constant and 'inhalation-only' cyclic flows, in terms of particle loading time effect, using different humidity conditions. Filters were exposed to generated polydisperse NaCl particles. Experiments were performed mimicking an 'inhalation-only' scenario with a cyclic flow of 85 l min(-1) as the minute volume [or 170 l min(-1) as mean inhalation flow (MIF)] and for two constant flows of 85 and 170 l min(-1), under three relative humidity (RH) levels of 10, 50, and 80%. Each test was performed for loading time periods of 6h and the particle penetration (10-205.4nm in electrical mobility diameter) was measured once every 2h. For a 10% RH, the penetration of smaller size particles (<80nm), including the most penetrating particle size (MPPS), decreased over time for both constant and cyclic flows. For 50 and 80% RH levels, the changes in penetration were typically observed in an opposite direction with l...Continue Reading

References

Aug 1, 1990·American Industrial Hygiene Association Journal·L M BrosseauJ S Evans
May 1, 1973·American Industrial Hygiene Association Journal·R G StaffordT J Rowland
Aug 25, 2000·Applied Occupational and Environmental Hygiene·E S Moyer, M S Bergman
Aug 25, 2000·Applied Occupational and Environmental Hygiene·S B Martin, E S Moyer
Jun 19, 2004·Inhalation Toxicology·G OberdörsterC Cox
Dec 14, 2005·The Annals of Occupational Hygiene·Anna BalazySergey A Grinshpun
May 15, 2008·The Annals of Occupational Hygiene·Robert M EningerSergey A Grinshpun
Jul 9, 2008·Journal of Occupational and Environmental Hygiene·Samy RengasamyRonald E Shaffer
Nov 18, 2008·Journal of Occupational and Environmental Hygiene·Jonathan P EshbaughKent C Hofacre
Sep 10, 2013·Journal of Occupational and Environmental Hygiene·Paul D GardnerKent C Hofacre
Jan 29, 2014·Journal of Occupational and Environmental Hygiene·Ali BahloulClaude Ostiguy

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Citations

Apr 21, 2016·The Annals of Occupational Hygiene·Shuang GaoSergey A Grinshpun

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