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Santandrea A, Marchal M, Chazelet S, Marsteau S. Measurement of inward leakage of full-face masks in EN and ISO standards: comparison of gas and aerosol test agents. Ann Work Expo Health 2024:wxae056. [PMID: 38985848 DOI: 10.1093/annweh/wxae056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 06/26/2024] [Indexed: 07/12/2024] Open
Abstract
In Europe, respiratory protective devices must be certified before they can be marketed. Among the parameters of interest, inward leakage (IL) characterizes the tightness between the face seal and the face, to verify that the device is well-designed. European standard EN 13274-1 (2001) and International Organization for Standardization (ISO) standard ISO 16900-1 (2019) specify that IL should be measured using sodium chloride (NaCl) aerosol or sulfur hexafluoride (SF6) gas. For reusable masks made of nonporous materials, both test agents are considered equally acceptable. However, the few studies that have compared IL values measured with various aerosols and gases have come to divergent conclusions. This work then aimed to measure IL with the test agents recommended by the standards to determine whether they are really equivalent. Since krypton (Kr) is an interesting candidate for replacing SF6 in standard tests, IL was assessed with SF6 and Kr simultaneously, and with NaCl aerosol using various calculation methods. Tests were carried out on 5 models of full-face masks donned on a headform connected to a breathing machine simulating 3 sinusoidal breathing rates of various intensities. The respirator fit on the headform was evaluated using a controlled negative pressure method to determine a manikin fit factor. Four scenarios were then tested to represent very poor, bad, good, and excellent fit. Gas concentration was measured using a mass spectrometer, and IL was calculated for SF6 and Kr. A combination of 3 devices allowed the determination of the number-based concentration of particles with diameters between 20 nm and 2 µm, and IL was calculated for each of the 33 channels, as well as using a cumulative number concentration. In addition, to comply with standards, a conversion was carried out to calculate IL using a cumulative mass concentration. The results of this work evidenced that the IL values measured with NaCl were systematically lower than those determined with gases. IL was also shown to vary with particle size, with a maximum value exceeding that calculated with cumulative concentrations (in number or mass). As part of the revision of the standards, protocols for measuring inward leakage should be redefined. On the one hand, acceptability thresholds should be re-evaluated according to the nature of the test agent (gas or aerosol), as it is clear that the 2 options do not give the same results for a given configuration. On the other hand, the aerosol leakage measurement protocol needs to be reworked to enable the measurement of a well-defined, robust, and reproducible inward leakage value.
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Affiliation(s)
- Audrey Santandrea
- INRS, Département Ingénierie des Procédés, 1 rue du Morvan, CS 60027, 54519 Vandoeuvre, Cedex, France
| | - Mathieu Marchal
- INRS, Département Ingénierie des Procédés, 1 rue du Morvan, CS 60027, 54519 Vandoeuvre, Cedex, France
| | - Sandrine Chazelet
- INRS, Département Ingénierie des Procédés, 1 rue du Morvan, CS 60027, 54519 Vandoeuvre, Cedex, France
| | - Stéphanie Marsteau
- INRS, Département Ingénierie des Procédés, 1 rue du Morvan, CS 60027, 54519 Vandoeuvre, Cedex, France
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Sipkens TA, Corbin JC, Oldershaw A, Smallwood GJ. Particle filtration efficiency measured using sodium chloride and polystyrene latex sphere test methods. Sci Data 2022; 9:756. [PMID: 36477095 PMCID: PMC9729174 DOI: 10.1038/s41597-022-01860-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 11/22/2022] [Indexed: 12/12/2022] Open
Abstract
Standards governing face masks differ in the test methods used to determine sub-micron particle filtration efficiency (PFE), such that the meaning of PFE is not universal. Unifying the meaning of PFE requires data using these different test methods to drive improvements in standards. This simple data set provides the equivalence between two major test methods used to assess PFE: (1) a test method using a neutralized, polydisperse sodium chloride (NaCl) and (2) a test method using an unneutralized, "monodisperse" polystyrene latex sphere (PSL) aerosols. Measurements are made on over 5800 real-world medical masks, leading to the establishment of a relationship between these two kinds of PFE for these products.
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Affiliation(s)
- Timothy A Sipkens
- Metrology Research Centre, National Research Council Canada, Ottawa, Canada.
| | - Joel C Corbin
- Metrology Research Centre, National Research Council Canada, Ottawa, Canada
| | - Andrew Oldershaw
- Metrology Research Centre, National Research Council Canada, Ottawa, Canada
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Sipkens TA, Corbin JC, Koukoulas T, Oldershaw A, Lavoie T, Norooz Oliaee J, Liu F, Leroux ID, Smallwood GJ, Lobo P, Green RG. Comparison of measurement systems for assessing number- and mass-based particle filtration efficiency. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2022; 19:629-645. [PMID: 35994755 DOI: 10.1080/15459624.2022.2114596] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The particle filtration efficiency (PFE) of a respirator or face mask is one of its key properties. While the physics of particle filtration results in the PFE being size-dependent, measurement standards are specified using a single, integrated PFE, for simplicity. This integrated PFE is commonly defined concerning either the number (NPFE) or mass (MPFE) distribution of particles as a function of size. This relationship is non-trivial; it is influenced by both the shape of the particle distribution and the fact that multiple practical definitions of particle size are used. This manuscript discusses the relationship between NPFE and MPFE in detail, providing a guide to practitioners. Our discussion begins with a description of the theory underlying different variants of PFE. We then present experimental results for a database of size-resolved PFE (SPFE) measurements for several thousand candidate respirators and filter media, including filter media with systematically varied properties and commercial samples that span 20%-99.8% MPFE. The observed relationships between NPFE and MPFE are discussed in terms of the most-penetrating particle size (MPPS) and charge state of the media. For the sodium chloride particles used here, we observed that the MPFE was greater than NPFE for charged materials and vice versa for uncharged materials. This relationship is observed because a shift from NPFE to MPFE weights the distribution toward larger sizes, while charged materials shift the MPPS to smaller sizes. Results are validated by comparing the output of a pair of automated filter testers, which are used in gauging standards compliance, to that of MPFE computed from a system capable of measuring SPFE over the 20 nm-500 nm range.
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Affiliation(s)
- Timothy A Sipkens
- Metrology Research Centre, National Research Council Canada, Ottawa, Ontario
| | - Joel C Corbin
- Metrology Research Centre, National Research Council Canada, Ottawa, Ontario
| | | | - Andrew Oldershaw
- Metrology Research Centre, National Research Council Canada, Ottawa, Ontario
| | - Thierry Lavoie
- Metrology Research Centre, National Research Council Canada, Ottawa, Ontario
| | - Jalal Norooz Oliaee
- Metrology Research Centre, National Research Council Canada, Ottawa, Ontario
| | - Fengshan Liu
- Metrology Research Centre, National Research Council Canada, Ottawa, Ontario
| | - Ian D Leroux
- Metrology Research Centre, National Research Council Canada, Ottawa, Ontario
| | - Gregory J Smallwood
- Metrology Research Centre, National Research Council Canada, Ottawa, Ontario
| | - Prem Lobo
- Metrology Research Centre, National Research Council Canada, Ottawa, Ontario
| | - Richard G Green
- Metrology Research Centre, National Research Council Canada, Ottawa, Ontario
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Heo KJ, Oh HJ, Eom H, Kim Y, Jung JH. High-performance bag filter with a super-hydrophobic microporous polytetrafluoroethylene layer fabricated by air-assisted electrospraying. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 783:147043. [PMID: 34088110 DOI: 10.1016/j.scitotenv.2021.147043] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 03/19/2021] [Accepted: 04/06/2021] [Indexed: 06/12/2023]
Abstract
Reducing PM emissions from industrial sites has become increasingly important as the adverse health effects of particulate matter have been demonstrated by multiple epidemiological and toxicological studies. High-performance bag filters are often used for this purpose. We fabricated polytetrafluoroethylene (PTFE) nanoparticle (NP)-coated high-efficiency bag filters using air-assisted electrospraying (AAES) technology. AAES functionalized with a combination of airflow drag force and an applied electric field facilitates high-throughput without requiring additional purification or preparation process of a PTFE emulsion. PTFE NPs form a unique three-dimensional microporous structure on a foam-filter medium, enhancing mechanical filtration performance (diffusion and interception). Moreover, the surface hydrophobicity was significantly improved as the PTFE NPs covered the bag filter surface. These factors highlight the feasibility of large-scale implementation of PTFE NP-coated bag filters for reducing PM emissions from industrial sources.
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Affiliation(s)
- Ki Joon Heo
- Advanced Textile R&D Department, Korea Institute of Industrial Technology (KITECH), Ansan 15588, Republic of Korea; Department of Environmental Machinery, Korea Institute of Machinery & Materials (KIMM), Daejeon 34103, Republic of Korea
| | - Hyun Ju Oh
- Advanced Textile R&D Department, Korea Institute of Industrial Technology (KITECH), Ansan 15588, Republic of Korea
| | - Hyeonjin Eom
- Thermochemical energy system R&D group, Korea Institute of Industrial Technology (KITECH), Chenan 31056, Republic of Korea
| | - Yeonsang Kim
- Advanced Textile R&D Department, Korea Institute of Industrial Technology (KITECH), Ansan 15588, Republic of Korea.
| | - Jae Hee Jung
- Department of Mechanical Engineering, Sejong University, Seoul 05006, Republic of Korea.
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Brochocka A, Okrasa M. Determination of paraffin oil mist penetration at high flow rates through air-purifying respirators. INTERNATIONAL JOURNAL OF OCCUPATIONAL SAFETY AND ERGONOMICS 2021; 28:62-67. [PMID: 34162316 DOI: 10.1080/10803548.2021.1935545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
This article presents paraffin oil mist penetration tests of commercially available air-purifying respirators of different construction conducted using the method described by Standard No. ISO 16900-3:2012, which incorporates flow rates (up to 255 l/min) of test aerosol. The testing method reflects differences in work intensity during the use of respirators. Moreover, the experimental stand, designed according to the international specifications, is described. The results show that the higher the paraffin oil mist flow rate, the higher the penetration index, irrespective of the testing method used and the type of respirator investigated. While at high flow rates, filtering half masks of the first protection class (FFP1) met the requirements of their protection class according to European Standard No. EN 149:20001+A1:2009, filtering half masks of the second and the third protection class (FFP2 and FFP3) did not.
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Affiliation(s)
- Agnieszka Brochocka
- Central Institute for Labour Protection - National Research Institute, Poland
| | - Małgorzata Okrasa
- Central Institute for Labour Protection - National Research Institute, Poland
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Ou Q, Pei C, Chan Kim S, Abell E, Pui DYH. Evaluation of decontamination methods for commercial and alternative respirator and mask materials - view from filtration aspect. JOURNAL OF AEROSOL SCIENCE 2020; 150:105609. [PMID: 32834104 PMCID: PMC7313496 DOI: 10.1016/j.jaerosci.2020.105609] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 06/03/2020] [Accepted: 06/04/2020] [Indexed: 05/20/2023]
Abstract
This study aims to evaluate the filtration performance of three commercially available (3M 8210 respirator, Halyard 48207 surgical mask, and 3M 1820 procedure mask) and two alternative face mask and respirator materials (Halyard H600 sterilization wrap and Cummins EX101) after selected decontamination treatments, including isopropanol (IPA) treatments (soaking or spraying), ultraviolet germicidal irradiation (UVGI), and heat treatments (dry heat at 77 °C or steam heat). Both IPA soaking and spraying removed most electrostatic charges on all four electret materials (three commercial and one alternative), causing significant deterioration of filtration efficiency to unacceptable level. The other non-electret alternative material sustained its N95-grade performance after both IPA soaking and spraying treatments, demonstrating the possible application of IPA disinfection for non-electret alternative respirator/mask materials. UVGI preserved the filtration of all three commercially available respirator/mask materials after up to 10 treatments, suggesting it can be a possible decontamination method for hospital and clinic use without compromising respirator/mask performance. The considerations of the practical implementation of this method was discussed. Between the two heat treatment methods tested, dry heat showed better compatibility with electret material by sustaining both filtration efficiency and fit (tested on commercial respirator only), although adding moisture was reported in favor of virus inactivation. Heat treatment is easily accessible method for general publics to implement at home, while it is recommended to maintain the moisture level below saturation. Comparing to size-integrated method, the size-resolved fractional efficiency measurement technique, although more time consuming, proved to be a better method for evaluating respirator/mask filtration performance after decontaminations by providing more sensitive detection of performance degradation and the capability of distinguishing charge loss to other mechanisms causing efficiency deterioration. Detailed descriptions are provided in methodology part to emphasize the cares needed for an appropriate efficiency evaluation. The limited results in this study on worn masks made of alternative sterilization wrap indicated possible performance degradation of electret material caused by normal human wearing activities, suggesting the need of assessing respirator/mask decontamination strategy by testing practically worn-and-decontaminated/reused samples instead of unworn only-decontaminated counterparts.
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Affiliation(s)
- Qisheng Ou
- Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Chenxing Pei
- Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Seong Chan Kim
- Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Elizabeth Abell
- Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN, 55455, USA
| | - David Y H Pui
- Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN, 55455, USA
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong, 518172, China
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Guan T, Hu S, Han Y, Wang R, Zhu Q, Hu Y, Fan H, Zhu T. The effects of facemasks on airway inflammation and endothelial dysfunction in healthy young adults: a double-blind, randomized, controlled crossover study. Part Fibre Toxicol 2018; 15:30. [PMID: 29973251 PMCID: PMC6032602 DOI: 10.1186/s12989-018-0266-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 06/15/2018] [Indexed: 12/18/2022] Open
Abstract
Background Facemasks are increasingly worn during air pollution episodes in China, but their protective effects are poorly understood. We aimed to evaluate the filtration efficiencies of N95 facemasks and the cardiopulmonary benefits associated with wearing facemasks during episodes of pollution. Results We measured the filtration efficiencies of particles in ambient air of six types of N95 facemasks with a manikin headform. The most effective one was used in a double-blind, randomized, controlled crossover study, involving 15 healthy young adults, conducted during 2 days of severe pollution in Beijing, China. Subjects were asked to walk along a busy-traffic road for 2 h wearing authentic or sham N95 facemasks. Clinical tests were performed four times to determine changes in the levels of biomarkers of airway inflammation, endothelial dysfunction, and oxidative stress within 24 h after exposure. The facemasks removed 48–75% of number concentrations of ambient air particles between 5.6 and 560 nm in diameter. After adjustments for multiple comparison, the exhaled nitric oxide level and the levels of interleukin-1α, interleukin-1β, and interleukin-6 in exhaled breath condensate increased significantly in all subjects; however, the increases in those wearing authentic facemasks were statistically significantly lower than in the sham group. No significant between-group difference was evident in the urinary creatinine-corrected malondialdehyde level. In arterial stiffness indicators, the ejection duration of subjects wearing authentic facemasks was higher after exposure compared to the sham group; no significant between-group difference was found in augmentation pressure or the augmentation index. Conclusions In young healthy adults, N95 facemasks partially reduced acute particle-associated airway inflammation, but neither systemic oxidative stress nor endothelial dysfunction improved significantly. The clinical significance of these findings long-term remains to be determined. Trial registration The trial registration number (TRN) for this study is ChiCTR1800016099, which was retrospectively registered on May 11, 2018. Electronic supplementary material The online version of this article (10.1186/s12989-018-0266-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Tianjia Guan
- BIC-EAST and SKL-ESPC, College of Environmental Sciences and Engineering and Centre for Environment and Health, Peking University, 5 Yiheyuan Road, Beijing, 100871, China.,School of Public Health, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100730, China
| | - Songhe Hu
- BIC-EAST and SKL-ESPC, College of Environmental Sciences and Engineering and Centre for Environment and Health, Peking University, 5 Yiheyuan Road, Beijing, 100871, China
| | - Yiqun Han
- BIC-EAST and SKL-ESPC, College of Environmental Sciences and Engineering and Centre for Environment and Health, Peking University, 5 Yiheyuan Road, Beijing, 100871, China
| | - Ruoyu Wang
- BIC-EAST and SKL-ESPC, College of Environmental Sciences and Engineering and Centre for Environment and Health, Peking University, 5 Yiheyuan Road, Beijing, 100871, China
| | - Qindan Zhu
- BIC-EAST and SKL-ESPC, College of Environmental Sciences and Engineering and Centre for Environment and Health, Peking University, 5 Yiheyuan Road, Beijing, 100871, China
| | - Yaoqian Hu
- BIC-EAST and SKL-ESPC, College of Environmental Sciences and Engineering and Centre for Environment and Health, Peking University, 5 Yiheyuan Road, Beijing, 100871, China
| | - Hanqing Fan
- BIC-EAST and SKL-ESPC, College of Environmental Sciences and Engineering and Centre for Environment and Health, Peking University, 5 Yiheyuan Road, Beijing, 100871, China
| | - Tong Zhu
- BIC-EAST and SKL-ESPC, College of Environmental Sciences and Engineering and Centre for Environment and Health, Peking University, 5 Yiheyuan Road, Beijing, 100871, China.
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The Effectiveness of Specific Risk Mitigation Techniques Used in the Production and Handling of Manufactured Nanomaterials: A Systematic Review. J UOEH 2017; 39:187-199. [PMID: 28904269 DOI: 10.7888/juoeh.39.187] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Many kinds of manufactured nanomaterials (MNMs) have been developed and used as basic materials of industrial products, and they may pose health risks for workers in not only developed countries but also in developing countries. Few studies have looked at the evidence for effects of controls that mitigate the risk of exposure to MNMs. Therefore, we systematically searched the literature from the year 2000 to 2015. We included studies that compared the use of an exposure control to the situation without such a technique and those that measured the exposure to MNMs as the outcome. In order to evaluate the effectiveness of these controls, we used their "protection factor", defined as the ratio between concentrations without and with the control. We located 1,131 references in PubMed and other lists, and out of these references, 41 studies fulfilled our inclusion criteria. We categorized them as engineering controls such as enclosure, local exhaust ventilation or process automation, and as personal protective equipment (PPE). For enclosure systems we found a protection factor beyond 100. For other engineering controls, the better controls scored 10 to 20, but many cases of local exhaust ventilation had a protection factor of less than 10 and some cases even increased exposure. PPE such as N95 or equivalent filtering respirators had a protection factor of approximately 10 tested with nano-sized aerosols. We conclude that there is low quality evidence that specific engineering controls can reduce exposure to MNMs but that enclosure is considerably more effective. For respiratory protection the evidence is of very low quality due to the lack of field studies. This information can be used to decide about controls when exposure to MNMs exceeds proposed occupational exposure limits or when no toxicological information is available for a MNM.
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Zuo Z, Kuehn TH, Pui DYH. Respirator Testing Using Virus Aerosol: Comparison between Viability Penetration and Physical Penetration. ANNALS OF OCCUPATIONAL HYGIENE 2015; 59:812-6. [PMID: 25846360 DOI: 10.1093/annhyg/mev019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Viability, fluorescence (particle volume), photometric, viral RNA, and particle number penetration of MS2 bacteriophage through filter media used in three different models of respirators were compared to better understand the correlation between viability and physical penetration. Although viability and viral RNA penetration were better represented by particle volume penetration than particle number penetration, they were several-fold lower than photometric penetration, which was partially due to the difference in virus survival between upstream and downstream aerosol samples. Results suggest that the current NIOSH photometer-based test method can be used as a quick means to roughly differentiate respirators with different performance against virus aerosols.
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Affiliation(s)
- Zhili Zuo
- Department of Mechanical Engineering, University of Minnesota, 111 Church St. SE, Minneapolis, MN 55455, USA
| | - Thomas H Kuehn
- Department of Mechanical Engineering, University of Minnesota, 111 Church St. SE, Minneapolis, MN 55455, USA
| | - David Y H Pui
- Department of Mechanical Engineering, University of Minnesota, 111 Church St. SE, Minneapolis, MN 55455, USA Faculty of Science, The University of Hong Kong, Hong Kong
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Rengasamy S, Walbert GF, Newcomb WE, Faulkner K, Rengasamy MM, Brannen JJ, Szalajda JV. Total inward leakage measurement of particulates for N95 filtering facepiece respirators--a comparison study. ACTA ACUST UNITED AC 2013; 58:206-16. [PMID: 24107745 DOI: 10.1093/annhyg/met054] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
National Institute for Occupational Safety and Health (NIOSH) certified particulate respirators need to be properly fit tested before use to ensure workers' respiratory protection. However, the effectiveness of American National Standards Institute-/Occupational Safety and Health Administration (ANSI-/OSHA)-accepted fit tests for particulate respirators in predicting actual workplace protection provided to workers is lacking. NIOSH addressed this issue by evaluating the fit of half-mask particulate filtering respirators as a component of a program designed to add total inward leakage (TIL) requirements for all respirators to Title 42 Code of Federal Regulations Part 84. Specifically, NIOSH undertook a validation study to evaluate the reproducibility of the TIL test procedure between two laboratories. A PortaCount® was used to measure the TIL of five N95 model filtering facepiece respirators (FFRs) on test subjects in two different laboratories. Concurrently, filter efficiency for four of the five N95 FFR models was measured using laboratory aerosol as well as polydisperse NaCl aerosol employed for NIOSH particulate respirator certification. Results showed that two N95 models passed the TIL tests at a rate of ~80-85% and ~86-94% in the two laboratories, respectively. However, the TIL passing rate for the other three N95 models was 0-5.7% in both laboratories combined. Good agreement (≥83%) of the TIL data between the two laboratories was obtained. The three models that had relatively lower filter efficiency for laboratory aerosol as well as for NaCl aerosol showed relatively low TIL passing rates in both laboratories. Of the four models tested for penetration, one model with relatively higher efficiency showed a higher passing rate for TIL tests in both laboratories indicating that filter efficiency might influence TIL. Further studies are needed to better understand the implications of the data in the workplace.
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Affiliation(s)
- Samy Rengasamy
- National Institute for Occupational Safety and Health, National Personal Protective Technology Laboratory, 626 Cochrans Mill Road, PO Box 18070, Pittsburgh, PA 15236, USA
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Rengasamy S, BerryAnn R, Szalajda J. Nanoparticle filtration performance of filtering facepiece respirators and canister/cartridge filters. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2013; 10:519-25. [PMID: 23927008 DOI: 10.1080/15459624.2013.818229] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Respiratory protection offered by a particulate respirator is a function of the filter efficiency and face seal leakage. A previous study in our laboratory measured the filter penetration and total inward leakage (TIL) of 20-1000 nm size particles for N95 filtering facepiece respirators (FFRs) using a breathing manikin. The results showed relatively higher filter penetration and TIL value under different leak sizes and flow rates at the most penetrating particle size (MPPS), ∼45 nm for electrostatic FFRs,and ∼150 nm for the same FFRs after charge removal. This indicates an advantage of mechanical filters over electrostatic filters rated for similar filter efficiencies in providing respiratory protection in nanoparticle workplaces. To better understand the influence of the MPPS, the filtration performance of commonly used one N95 and one N100 FFR models, and four P100 canister/cartridge models were measured with monodisperse NaCl aerosols, and polydisperse NaCl aerosols employed in the National Institute for Occupational Safety and Health (NIOSH) certification test method. As expected, the polydisperse aerosol penetration was below 5% for the N95 FFR, and below 0.03% for the N100 FFR and P100 canister/cartridge filters. Monodisperse aerosol penetration results showed a MPPS of ∼40 nm for both the N95 and N100 FFRs. All four P100 canister/cartridge filters had a MPPS of ≥150 nm, similar to expectations for mechanical filters. The P100 canister/cartridge filters showed lower penetration values for different size nanoparticles than the N100 FFRs. The results indicate that a mechanical filter would offer a relatively higher filtration performance for nanoparticles than an electrostatic counterpart rated for the same filter efficiency. Overall, the results obtained in the study suggest that MPPS should be considered as a key factor in the development of respirator standards and recommendations for protection against nanoparticles.
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Affiliation(s)
- Samy Rengasamy
- National Personal Protective Technology Laboratory, National Institute for Occupational Safety and Health, Pittsburgh, PA 15236, USA.
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