Nanoparticle penetration through NIOSH-approved N95 filtering-facepiece respirators.
Rengasamy-S; Verbofsky-R; King-WB; Shaffer-RE
J Int Soc Respir Prot 2007 Mar; 24(Spring/Summer):49-59
The aim of this study was to compare NaCI particle penetration through five NIOSH-approved N95 filtering-facepiece respirator models using two test methods. Data from a polydisperse aerosol challenge similar to the NIOSH respirator certification test was compared to data collected using monodisperse aerosols ranging from 20 nm to 400 nm. The average initial penetration levels from the polydisperse aerosol tests ranged from 0.61 % to 1.24% for the five respirator models tested. Monodisperse aerosol penetrations behaved according to single fiber filtration theory. The most penetrating particle size was found to be near 40 nm. Average penetration of 40 nm particles was found to exceed 5% for two respirator models, but was not statistically significant compared to the 5% criteria for class "95" respirators used by NIOSH with the certification test. The rank ordering of the filtration performances of the five respirator models was consistent between the two test methods.
Respirators; Respiratory-protective-equipment; Respiratory-protection; Aerosols; Personal-protective-equipment; Personal-protection
National Institute for Occupational Safety and Health, National Personal Protective Technology Laboratory, 626 Cochrans Mill Road, P.O.Box 18070, Pittsburgh, PA 15236, USA
Issue of Publication
Journal of the International Society for Respiratory Protection