242. Performance of Class 95 Electret Filters Against Diesel Particulate Matter

Janssen, Larry; Bidwell, J.

doi:10.3320/1.2758603

Cited by 5 publications

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“… 8 9 Studies often test the filtration efficiency of a section of the mask filter material in a sample holder or on mannequin heads, usually sealing the mask to the mannequin’s face. One study investigated the filtration efficiency of mask filter material complying with the N95 criteria (filtering ≥95% particulate, online supplementary table S1 ), 10 finding that between <0.5% and 4.3% of the diesel aerosol, measured as elemental carbon, passed through the filters. Langrish et al 4 demonstrated that several mask materials allowed <5% of a diesel exhaust challenge through the material.…”

Section: Introductionmentioning

confidence: 99%

Effectiveness of face masks used to protect Beijing residents against particulate air pollution

et al. 2018

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ObjectivesMany residents in Beijing use disposable face masks in an attempt to protect their health from high particulate matter (PM) concentrations. Retail masks may be certified to local or international standards, but their real-life performance may not confer the exposure reduction potential that is marketed. This study aimed to evaluate the effectiveness of a range of face masks that are commercially available in China.MethodsNine masks claiming protection against fine PM (PM2.5) were purchased from consumer outlets in Beijing. The masks’ filtration efficiency was tested by drawing airborne diesel exhaust through a section of the material and measuring the PM2.5 and black carbon (BC) concentrations upstream and downstream of the filtering medium. Four masks were selected for testing on volunteers. Volunteers were exposed to diesel exhaust inside an experimental chamber while performing sedentary tasks and active tasks. BC concentrations were continuously monitored inside and outside the mask.ResultsThe mean per cent penetration for each mask material ranged from 0.26% to 29%, depending on the flow rate and mask material. In the volunteer tests, the average total inward leakage (TIL) of BC ranged from 3% to 68% in the sedentary tests and from 7% to 66% in the active tests. Only one mask type tested showed an average TIL of less than 10%, under both test conditions.ConclusionsMany commercially available face masks may not provide adequate protection, primarily due to poor facial fit. Our results indicate that further attention should be given to mask design and providing evidence-based guidance to consumers.

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Section: Introductionmentioning

confidence: 99%

Effectiveness of face masks used to protect Beijing residents against particulate air pollution

et al. 2018

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“…Very few studies tested the N95 filter performance against aerosols in the occupational environments particles such as diesel exhaust and welding fume particles. Janssen and Bidwell (2006) investigated performance of two N95 FFRs exposed to diesel engine exhaust and measured concentration of elemental carbon as index of diesel exhaust particles. Penetrations of 1.12 and 2.71% were obtained after 2-and 8-hour exposure for one respirator; for another respirator, penetrations of 12.1 and 11.5 % were obtained.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of N95 Filtering Facepiece Respirators Challenged with Engineered Nanoparticles

Zhou

Cheng

2016

Aerosol Air Qual. Res.

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NIOSH-certified respirators, including N95 respirators, are recommended when engineering and administrative controls do not adequately prevent exposures to airborne nanomaterials. Laboratory evaluations of filtering efficiency using standard test aerosols have been reported in the literature, but there is no information on penetration of engineered nanoparticles (1-100 nm) for N95 filtering facepiece respirators (FFR). This project evaluated the performance of two manufacturers' N95 FFR filters challenged with engineered nanoparticle aerosols containing metal oxides (such as TiO 2 ) and carbon (such as fullerenes and nanotubes) in contrast with a sodium chloride (NaCl) aerosol at flow rates of 30, 85, and 130 L min -1 . For new respirator filters in general, NaCl aerosol penetration was less than 5% and the most penetrating particle size occurred at 40 nm. Overall penetration of the engineered nanoparticle aerosols exceeded 5% and was often greater than 5% at and near the most penetrating particle size (MPPS), which occurred at a larger particle size range (90-150 nm). For respirators treated with isopropanol in which the electrostatic force was removed, penetration of NaCl and engineered nanoparticles increased substantially and the MPPS increased to 150 nm for both types of aerosols. Our results indicated that a possible reason for higher maximum penetrations and shift of MPPS observed for these engineered nanoparticles in the new respirators was related to electrostatic collection processes.

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“…(28,29) The photometric filter penetration test method measures larger than 100 nm size aerosol particles with significant mass found in many conventional workplaces. However, the photometric method is not sensitive to measure nanoparticles with no significant mass.…”

Section: Room Airmentioning

confidence: 99%

Nanoparticle Filtration Performance of NIOSH-Certified Particulate Air-Purifying Filtering Facepiece Respirators: Evaluation by Light Scattering Photometric and Particle Number-Based Test Methods

Rengasamy

Eimer²

2012

Journal of Occupational and Environmental Hygiene

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National Institute for Occupational Safety and Health (NIOSH) certification test methods employ charge neutralized NaCl or dioctyl phthalate (DOP) aerosols to measure filter penetration levels of air-purifying particulate respirators photometrically using a TSI 8130 automated filter tester at 85 L/min. A previous study in our laboratory found that widely different filter penetration levels were measured for nanoparticles depending on whether a particle number (count)-based detector or a photometric detector was used. The purpose of this study was to better understand the influence of key test parameters, including filter media type, challenge aerosol size range, and detector system. Initial penetration levels for 17 models of NIOSH-approved N-, R-, and P-series filtering facepiece respirators were measured using the TSI 8130 photometric method and compared with the particle number-based penetration (obtained using two ultrafine condensation particle counters) for the same challenge aerosols generated by the TSI 8130. In general, the penetration obtained by the photometric method was less than the penetration obtained with the number-based method. Filter penetration was also measured for ambient room aerosols. Penetration measured by the TSI 8130 photometric method was lower than the number-based ambient aerosol penetration values. Number-based monodisperse NaCl aerosol penetration measurements showed that the most penetrating particle size was in the 50 nm range for all respirator models tested, with the exception of one model at ~200 nm size. Respirator models containing electrostatic filter media also showed lower penetration values with the TSI 8130 photometric method than the number-based penetration obtained for the most penetrating monodisperse particles. Results suggest that to provide a more challenging respirator filter test method than what is currently used for respirators containing electrostatic media, the test method should utilize a sufficient number of particles <100 nm and a count (particle number)-based detector.

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242. Performance of Class 95 Electret Filters Against Diesel Particulate Matter

Cited by 5 publications

References 0 publications

Effectiveness of face masks used to protect Beijing residents against particulate air pollution

Effectiveness of face masks used to protect Beijing residents against particulate air pollution

Evaluation of N95 Filtering Facepiece Respirators Challenged with Engineered Nanoparticles

Nanoparticle Filtration Performance of NIOSH-Certified Particulate Air-Purifying Filtering Facepiece Respirators: Evaluation by Light Scattering Photometric and Particle Number-Based Test Methods

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