1
|
Maciejewska M, Przybyła M, Szczurek A. Aerosol penetration study for FFP2 half masks regarding protection against diesel particles in underground mines. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2023; 20:480-492. [PMID: 37656966 DOI: 10.1080/15459624.2023.2238022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/03/2023]
Abstract
Filtering facepieces (FFP), mainly class FFP2 particle half masks (EN 149:2001#x02009;+ A1:2009), are commonly used in European mines to protect workers from respirable dust, especially from particulate matter (PM) with a diameter of 4 µm or less (PM4). The aerosol associated with diesel exhaust (DE) is dominated by submicrometer particles (with a diameter of less than 1 µm) and nanoparticles (size in the range between 10 and 500 nm). In the European Union (EU), the occupational exposure level (OEL) for DE has been defined in terms of elemental carbon (EC) concentration. Based on measurements in underground mines, on average, 60% of EC associated with PM4 was contained in PM with a diameter of 1 µm or less (PM1). Particle number size distribution (PNSD) of PM1 showed that the most numerous were particles in the size range of 20 to 300 nm. Four popular types of certified FFP2 half masks were tested for penetration. Brand new and thermally conditioned masks of each type were included in the study. NaCl aerosol in the particle size range of 7 to 270 nm was used for tests. Filtration efficiencies of 98.5% (median) or higher were achieved. Aerosol penetration was a function of particle size. Maximum penetration was observed between 20 and 60 nm, depending on the type of mask. During filtration, aerosol characteristics changed. Nanoparticles ranging in size from 7 to about 60 nm were removed to a very limited extent. The change was more noticeable for brand-new masks compared to the thermally conditioned ones. Usually, aerosol penetration through thermally conditioned masks was lower and more consistent. It was confirmed that the half masks of the FFP2 class are capable of filtering submicrometer aerosol in particle size range 7 to 270 nm with an efficiency exceeding 96% and can contribute to achieving compliance with the OEL for DE in the mining sector.
Collapse
Affiliation(s)
- Monika Maciejewska
- Faculty of Environmental Engineering, Wroclaw University of Science and Technology, Wrocław, Poland
| | - Marcin Przybyła
- Faculty of Environmental Engineering, Wroclaw University of Science and Technology, Wrocław, Poland
- Centrum Badań Jakości sp. z o. o., Capital Group KGHM Polska Miedź S.A, Lubin, Poland
| | - Andrzej Szczurek
- Faculty of Environmental Engineering, Wroclaw University of Science and Technology, Wrocław, Poland
| |
Collapse
|
2
|
Teng G, Shi G, Zhu J, Zhao C. Research on the air supply adjustment technology of breath-following powered air-purifying respirators. Sci Rep 2023; 13:12219. [PMID: 37500814 PMCID: PMC10374598 DOI: 10.1038/s41598-023-39411-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 07/25/2023] [Indexed: 07/29/2023] Open
Abstract
In the hope of reducing the air supply flow of the powered air-purifying respirator (PAPR) and extending the service life of the filter, a breath-following powered air-purifying respirator (BF-PAPR) that can dynamically adjust the air supply flow according to the breathing flow is proposed. The BF-PAPR changes the air supply flow by adjusting the speed of the variable-frequency centrifugal fan according to the air velocity at the half mask outlet (vhm) monitored by the modular wind speed transmitter. In the study, the air supply flow adjustment model of the BF-PAPR is developed. It is found that the filtration resistance barely influences vhm. In addition, under the same mean inhalation flow, the minimum outlet air velocity increases first and then decreases with the increase of the duty cycle variation coefficient (λ), while the maximum outlet air velocity decreases first and then increases. Moreover, the minimum air supply flow of the BF-PAPR is achieved when the standard value of the air velocity is 13.4 m/s and the value of λ is 1. The BF-PAPR can reduce the air supply flow by 6.5%-8.6% and the energy consumption by approximately 20% compared with the PAPR, which is beneficial for reducing the usage cost and extending the continuous working time.
Collapse
Affiliation(s)
- Guangping Teng
- College of Safety Engineering, School of Safety Engineering, China University of Mining and Technology, Xuzhou, 221116, China
- School of Safety and Management Engineering, Hunan Institute of Technology, Hengyang, 421002, China
| | - Guoqing Shi
- College of Safety Engineering, School of Safety Engineering, China University of Mining and Technology, Xuzhou, 221116, China.
- State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology, Xuzhou, 221116, China.
| | - Jintuo Zhu
- College of Safety Engineering, School of Safety Engineering, China University of Mining and Technology, Xuzhou, 221116, China
| | - Caijun Zhao
- School of Safety and Management Engineering, Hunan Institute of Technology, Hengyang, 421002, China
| |
Collapse
|
3
|
Saravanan P, Broccolo F, Ali N, Toh A, Mulyana S, Beng GL, Imperi E, Picano A. A new aerodynamic endonasal filtration technology for protection against pollutants and respiratory infectious agents: evaluation of the particle filtration efficacy. FRONTIERS IN MEDICAL TECHNOLOGY 2023; 5:1219996. [PMID: 37546386 PMCID: PMC10401429 DOI: 10.3389/fmedt.2023.1219996] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 07/03/2023] [Indexed: 08/08/2023] Open
Abstract
An innovative nasal filter was tested, based on aerodynamic air filtration and not on conventional air filtration by means of mesh filters. A custom testing system was designed and three sizes of the filter have been tested vs. monodispersed SiO2 particles sized 5 μm, 1 μm, and 0.5 μm under cycling flow of 6 liters per minute, provided by an artificial lung breather simulating spontaneous breathing. Accelerated testing was implemented, challenging filters with a maximum load of 200 mg per cubic meter. All three filters' sizes showed initial filtration efficiencies above 90% vs. all particles' sizes, decreased to not less than 80% after 30 min of accelerated testing, corresponding to 4.5 days of continuous use at 2 mg challenge, this value being associated with hazardous air conditions in the PSI scale. Results in this study indicate that nasal filters based on aerodynamic air filtration can provide fine and ultrafine filtration, offering protection in day-to-day life from risks associated with pollens, mites, PM, pollutants, and respiratory infectious agents, introducing acceptable respiratory resistance.
Collapse
Affiliation(s)
| | - Francesco Broccolo
- Department of Biological and Environmental Sciences and Technologies (DiSTeBA), University of Salento, Lecce, Italy
| | - Nurshahidah Ali
- School of Applied Science, Temasek Polytechnic, Singapore, Singapore
| | - Alden Toh
- School of Applied Science, Temasek Polytechnic, Singapore, Singapore
| | - Sakinah Mulyana
- School of Applied Science, Temasek Polytechnic, Singapore, Singapore
| | - Goh Lay Beng
- School of Applied Science, Temasek Polytechnic, Singapore, Singapore
| | | | | |
Collapse
|
4
|
Chen TX, Pinharanda A, Steinemann NA, Yasuma-Mitobe K, Lee E, Hahn J, Wu L, Fanourakis S, Peterka DS, Hillman EMC. Evaluation of at-home methods for N95 filtering facepiece respirator decontamination. Sci Rep 2021; 11:19750. [PMID: 34611228 PMCID: PMC8492771 DOI: 10.1038/s41598-021-99129-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Accepted: 09/14/2021] [Indexed: 11/17/2022] Open
Abstract
N95 filtering facepiece respirators (FFRs) are essential for the protection of healthcare professionals and other high-risk groups against Coronavirus Disease of 2019 (COVID-19). In response to shortages in FFRs during the ongoing COVID-19 pandemic, the Food and Drug Administration issued an Emergency Use Authorization permitting FFR decontamination and reuse. However, although industrial decontamination services are available at some large institutions, FFR decontamination is not widely accessible. To be effective, FFR decontamination must (1) inactivate the virus; (2) preserve FFR integrity, specifically fit and filtering capability; and (3) be non-toxic and safe. Here we identify and test at-home heat-based methods for FFR decontamination that meet these requirements using common household appliances. Our results identify potential protocols for simple and accessible FFR decontamination, while also highlighting unsuitable methods that may jeopardize FFR integrity.
Collapse
Affiliation(s)
- T X Chen
- Mortimer B. Zuckerman Mind Brain Behavior Institute, New York, NY, 10027, USA
| | - A Pinharanda
- Department of Biological Sciences, Columbia University, New York, NY, 10027, USA
| | - N A Steinemann
- Mortimer B. Zuckerman Mind Brain Behavior Institute, New York, NY, 10027, USA
| | - K Yasuma-Mitobe
- Department of Microbiology and Immunology, Columbia University, New York, NY, 10032, USA
| | - E Lee
- Columbia College, Columbia University, New York, NY, 10032, USA
| | - J Hahn
- Department of Biomedical Engineering, Columbia University, New York, NY, 10027, USA
| | - L Wu
- Columbia College, Columbia University, New York, NY, 10032, USA
| | - S Fanourakis
- Environmental Health and Safety, Columbia University, New York, NY, 10032, USA
| | - D S Peterka
- Mortimer B. Zuckerman Mind Brain Behavior Institute, New York, NY, 10027, USA.
| | - E M C Hillman
- Mortimer B. Zuckerman Mind Brain Behavior Institute, New York, NY, 10027, USA.
- Department of Biomedical Engineering, Columbia University, New York, NY, 10027, USA.
- Department of Radiology, Columbia University, New York, NY, 10027, USA.
| |
Collapse
|
5
|
Lowther SD, Deng W, Fang Z, Booker D, Whyatt DJ, Wild O, Wang X, Jones KC. How efficiently can HEPA purifiers remove priority fine and ultrafine particles from indoor air? ENVIRONMENT INTERNATIONAL 2020; 144:106001. [PMID: 32739515 DOI: 10.1016/j.envint.2020.106001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 07/16/2020] [Accepted: 07/18/2020] [Indexed: 05/27/2023]
Abstract
More than 1 million premature deaths in Asia annually are estimated to be associated with indoor air quality. HEPA (high-efficiency particulate air) filter air purifiers (APs) are widely used in urban Chinese residences by the growing middle class, as public awareness of air pollution increases. Currently, understanding of how particle size affects particle removal is inconsistent, and the rate at which different particle types are removed remains largely unknown. Therefore, this investigation aimed to determine the relationship between particle size and the removal efficiency of particles, and how efficiently ambient air is filtered compared to particle types which are typically used in standard tests (tobacco smoke, dust and pollen). Three of the most popular AP models in China were tested in China's largest indoor controlled chamber laboratory and the removal efficiencies of particles in the 18-514 nm range were identified. Each AP had a distinct profile of removal efficiency against particle size, but the three APs shared similarities in performance, with removal efficiency consistently lowest at 200-250 nm. This size fraction is important in an exposure context as these particles are abundant in ambient air in mega-cities, can penetrate through building shells effectively, remain airborne for long periods of time and can penetrate the deepest areas of the lungs. Ambient air particles were removed at a similar rate to test particles; this confirms that the Association of Home Appliance Manufacturers' (AHAM) standards are a suitable proxy for "real world" performance.
Collapse
Affiliation(s)
- Scott D Lowther
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, United Kingdom; State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Rd, Tianhe, Guangzhou 510640, China
| | - Wei Deng
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Rd, Tianhe, Guangzhou 510640, China
| | - Zheng Fang
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Rd, Tianhe, Guangzhou 510640, China
| | - Douglas Booker
- NAQTS, Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, United Kingdom
| | - Duncan J Whyatt
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, United Kingdom
| | - Oliver Wild
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, United Kingdom
| | - Xinming Wang
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Rd, Tianhe, Guangzhou 510640, China.
| | - Kevin C Jones
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, United Kingdom.
| |
Collapse
|
6
|
Wu B, Corey J, Yermakov M, Liu Y, Grinshpun SA. Laboratory Evaluation of a Novel Real-Time Respirator Seal Integrity Monitor. Ann Work Expo Health 2018; 62:742-753. [PMID: 29688252 DOI: 10.1093/annweh/wxy026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 04/06/2018] [Indexed: 11/14/2022] Open
Abstract
Background A low-cost real-time Respirator Seal Integrity Monitor (ReSIM) was recently developed to monitor a respirator's actual performance at a workplace. The objective of this study was to evaluate the capability of the new ReSIM prototype in manikin-based laboratory experiments to rapidly detect induced leakage of a half-mask elastomeric respirator. Methods Two phases of testing were conducted in this study. First, the accuracy of ReSIM measuring an aerosol concentration was assessed by comparing the outputs of ReSIM against a reference optical aerosol spectrometer (OAS) in a flow-through set-up. Second, the capability to detect a leak was tested using a manikin-based set-up to simulate leaks into a functional respirator. Results The regression curve of ReSIM versus OAS had an R2 of 0.936, indicating its high accuracy within the targeted particle size range of 0.5-2 µm. The ReSIM provided a leak detection sensitivity (probability of correctly identifying intervals with the true leak) of 98.4% when challenged with a combustion aerosol, compared to 71.8% when challenged with a NaCl aerosol. Its specificity (probability of identifying intervals without a leak) was 99.8% after adjusting for persistent false positives for both types of challenge aerosol. Conclusion The ReSIM prototype not only can estimate the particle concentration with high accuracy but also can rapidly detect respirator faceseal leakage in real time with sufficient sensitivity and specificity. In addition, it can trigger an alarm when the faceseal integrity is compromised.
Collapse
Affiliation(s)
- Bingbing Wu
- Center for Health-Related Aerosol Studies, Department of Environmental Health, College of Medicine, University of Cincinnati, Cincinnati, OH, USA
| | - Jonathan Corey
- Department of Civil and Architectural Engineering and Construction Management, College of Engineering and Applied Science, University of Cincinnati, Cincinnati, OH, USA
| | - Michael Yermakov
- Center for Health-Related Aerosol Studies, Department of Environmental Health, College of Medicine, University of Cincinnati, Cincinnati, OH, USA
| | - Yan Liu
- Department of Civil and Architectural Engineering and Construction Management, College of Engineering and Applied Science, University of Cincinnati, Cincinnati, OH, USA
| | - Sergey A Grinshpun
- Center for Health-Related Aerosol Studies, Department of Environmental Health, College of Medicine, University of Cincinnati, Cincinnati, OH, USA
| |
Collapse
|
7
|
Cherrie JW, Apsley A, Cowie H, Steinle S, Mueller W, Lin C, Horwell CJ, Sleeuwenhoek A, Loh M. Effectiveness of face masks used to protect Beijing residents against particulate air pollution. Occup Environ Med 2018; 75:446-452. [PMID: 29632130 PMCID: PMC5969371 DOI: 10.1136/oemed-2017-104765] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 01/12/2018] [Accepted: 03/12/2018] [Indexed: 11/23/2022]
Abstract
Objectives Many 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. Methods Nine 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. Results The 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. Conclusions Many 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.
Collapse
Affiliation(s)
- John W Cherrie
- Institute of Occupational Medicine, Centre for Human Exposure Science, Edinburgh, UK.,Institute of Biological Chemistry, Biophysics and Bioengineering, Heriot-Watt University, Edinburgh, UK
| | - Andrew Apsley
- Institute of Occupational Medicine, Centre for Human Exposure Science, Edinburgh, UK
| | - Hilary Cowie
- Institute of Occupational Medicine, Centre for Human Exposure Science, Edinburgh, UK
| | - Susanne Steinle
- Institute of Occupational Medicine, Centre for Human Exposure Science, Edinburgh, UK
| | - William Mueller
- Institute of Occupational Medicine, Centre for Human Exposure Science, Edinburgh, UK
| | - Chun Lin
- School of Chemistry, University of Edinburgh, Edinburgh, UK
| | - Claire J Horwell
- Department of Earth Sciences, Institute of Hazard, Risk and Resilience, Durham University, Durham, UK
| | - Anne Sleeuwenhoek
- Institute of Occupational Medicine, Centre for Human Exposure Science, Edinburgh, UK
| | - Miranda Loh
- Institute of Occupational Medicine, Centre for Human Exposure Science, Edinburgh, UK
| |
Collapse
|
8
|
Zhou SS, Lukula S, Chiossone C, Nims RW, Suchmann DB, Ijaz MK. Assessment of a respiratory face mask for capturing air pollutants and pathogens including human influenza and rhinoviruses. J Thorac Dis 2018; 10:2059-2069. [PMID: 29707364 DOI: 10.21037/jtd.2018.03.103] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Background Prevention of infection with airborne pathogens and exposure to airborne particulates and aerosols (environmental pollutants and allergens) can be facilitated through use of disposable face masks. The effectiveness of such masks for excluding pathogens and pollutants is dependent on the intrinsic ability of the masks to resist penetration by airborne contaminants. This study evaluated the relative contributions of a mask, valve, and Micro Ventilator on aerosol filtration efficiency of a new N95 respiratory face mask. Methods The test mask was challenged, using standardized methods, with influenza A and rhinovirus type 14, bacteriophage ΦΧ174, Staphylococcus aureus (S. aureus), and model pollutants. The statistical significance of results obtained for different challenge microbial agents and for different mask configurations (masks with operational or nonoperational ventilation fans and masks with sealed Smart Valves) was assessed. Results The results demonstrate >99.7% efficiency of each test mask configuration for exclusion of influenza A virus, rhinovirus 14, and S. aureus and >99.3% efficiency for paraffin oil and sodium chloride (surrogates for PM2.5). Statistically significant differences in effectiveness of the different mask configurations were not identified. The efficiencies of the masks for excluding smaller-size (i.e., rhinovirus and bacteriophage ΦΧ174) vs. larger-size microbial agents (influenza virus, S. aureus) were not significantly different. Conclusions The masks, with or without features intended for enhancing comfort, provide protection against both small- and large-size pathogens. Importantly, the mask appears to be highly efficient for filtration of pathogens, including influenza and rhinoviruses, as well as the fine particulates (PM2.5) present in aerosols that represent a greater challenge for many types of dental and surgical masks. This renders this individual-use N95 respiratory mask an improvement over the former types of masks for protection against a variety of environmental contaminants including PM2.5 and pathogens such as influenza and rhinoviruses.
Collapse
Affiliation(s)
| | | | | | | | | | - M Khalid Ijaz
- Research and Development, RB, Montvale, NJ, USA.,Medgar Evers College of the City University of New York (CUNY), Brooklyn, NY, USA
| |
Collapse
|
9
|
Satish S, Swanson JJ, Xiao K, Viner AS, Kittelson DB, Pui DYH. Gravimetric Measurements of Filtering Facepiece Respirators Challenged With Diesel Exhaust. Ann Work Expo Health 2017; 61:737-747. [DOI: 10.1093/annweh/wxx044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 05/24/2017] [Indexed: 11/12/2022] Open
|
10
|
Gao S, Kim J, Yermakov M, Elmashae Y, He X, Reponen T, Zhuang Z, Rengasamy S, Grinshpun SA. Performance of N95 FFRs Against Combustion and NaCl Aerosols in Dry and Moderately Humid Air: Manikin-based Study. THE ANNALS OF OCCUPATIONAL HYGIENE 2016; 60:748-60. [PMID: 27094179 PMCID: PMC6311389 DOI: 10.1093/annhyg/mew019] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 03/07/2016] [Indexed: 12/30/2022]
Abstract
OBJECTIVES The first objective of this study was to evaluate the penetration of particles generated from combustion of plastic through National Institute for Occupational Safety and Health (NIOSH)-certified N95 filtering facepiece respirators (FFRs) using a manikin-based protocol and compare the data to the penetration of NaCl particles. The second objective was to investigate the effect of relative humidity (RH) on the filtration performance of N95 FFRs. METHODS Two NIOSH-certified N95 FFRs (A and B) were fully sealed on a manikin headform and challenged with particles generated by combustion of plastic and NaCl particles. The tests were performed using two cyclic flows [with mean inspiratory flow (MIF) rates = 30 and 85 l min(-1), representing human breathing under low and moderate workload conditions] and two RH levels (≈20 and ≈80%, representing dry and moderately humid air). The total and size-specific particle concentrations inside (C in) and outside (C out) of the respirators were measured with a condensation particle counter and an aerosol size spectrometer. The penetration values (C in/C out) were calculated after each test. RESULTS The challenge aerosol, RH, MIF rate, and respirator type had significant (P < 0.05) effects on the performance of the manikin-sealed FFR. Its efficiency significantly decreased when the FFR was tested with plastic combustion particles compared to NaCl aerosols. For example, at RH ≈80% and MIF = 85 l min(-1), as much as 7.03 and 8.61% of combustion particles penetrated N95 respirators A and B, respectively. The plastic combustion particles and gaseous compounds generated by combustion likely degraded the electric charges on fibers, which increased the particle penetration. Increasing breathing flow rate or humidity increased the penetration (reduced the respirator efficiency) for all tested aerosols. The effect of particle size on the penetration varied depending on the challenge aerosol and respirator type. It was observed that the peak of the size distribution of combustion particles almost coincided with their most penetrating particle size, which was not the case for NaCl particles. This finding was utilized for the data interpretation. CONCLUSIONS N95 FFRs have lower filter efficiency when challenged with contaminant particles generated by combustion, particularly when used under high humidity conditions compared to NaCl particles.
Collapse
Affiliation(s)
- Shuang Gao
- 1Center for Health-Related Aerosol Studies, Department of Environmental Health, University of Cincinnati, 160 Panzeca Way, Cincinnati, OH 45267-0056, USA
| | - Jinyong Kim
- 1Center for Health-Related Aerosol Studies, Department of Environmental Health, University of Cincinnati, 160 Panzeca Way, Cincinnati, OH 45267-0056, USA
| | - Michael Yermakov
- 1Center for Health-Related Aerosol Studies, Department of Environmental Health, University of Cincinnati, 160 Panzeca Way, Cincinnati, OH 45267-0056, USA
| | - Yousef Elmashae
- 1Center for Health-Related Aerosol Studies, Department of Environmental Health, University of Cincinnati, 160 Panzeca Way, Cincinnati, OH 45267-0056, USA
| | - Xinjian He
- 2Industrial Management and Systems Engineering, College of Engineering and Mineral Resources, West Virginia University, 395 Evansdale Drive, Morgantown, WV 26506-6070, USA
| | - Tiina Reponen
- 1Center for Health-Related Aerosol Studies, Department of Environmental Health, University of Cincinnati, 160 Panzeca Way, Cincinnati, OH 45267-0056, USA
| | - Ziqing Zhuang
- 3Policy and Standard Development Branch, National Institute for Occupational Safety and Health, National Personal Protective Technology Laboratory, 626 Cochrans Mill Road, Pittsburgh, PA 15236, USA
| | - Samy Rengasamy
- 3Policy and Standard Development Branch, National Institute for Occupational Safety and Health, National Personal Protective Technology Laboratory, 626 Cochrans Mill Road, Pittsburgh, PA 15236, USA
| | - Sergey A Grinshpun
- 1Center for Health-Related Aerosol Studies, Department of Environmental Health, University of Cincinnati, 160 Panzeca Way, Cincinnati, OH 45267-0056, USA;
| |
Collapse
|