Decontamination of N95 respirators is being used by clinicians in the face of a global shortage of these devices. Some treatments for decontamination, such as some vaporized hydrogen peroxide methods or ultraviolet methods, had no impact on respiratory performance, while other treatments resulted in substantial damage to masks

Cyr, Jay

Ellison, Richard T.

Furtado, Ryan M.

Hollenbeck, Brian L.

Kobayashi, Kimiyoshi J.

Lanza, Jennifer

Peltier, Richard E.

Wang, Jiayuan

English

Ellison, Richard T., III

eScholarship@UMMS

University of Massachusetts Medical School eScholarship@UMMS Open Access Articles Open Access Publications by UMMS Authors 2020-07-16 Addressing decontaminated respirators: Some methods appear to damage mask integrity and protective function Richard E. Peltier University of Massachusetts Amherst Et al. Let us know how access to this document benefits you. Follow this and additional works at: https://escholarship.umassmed.edu/oapubs  Part of the Clinical Epidemiology Commons, Epidemiology Commons, Equipment and Supplies Commons, Health and Medical Administration Commons, Health Services Administration Commons, Health Services Research Commons, Infectious Disease Commons, Occupational Health and Industrial Hygiene Commons, and the Virus Diseases Commons Repository Citation Peltier RE, Wang J, Hollenbeck BL, Lanza J, Furtado RM, Cyr J, Ellison RT, Kobayashi KJ. (2020). Addressing decontaminated respirators: Some methods appear to damage mask integrity and protective function. Open Access Articles. https://doi.org/10.1017/ice.2020.332. Retrieved from https://escholarship.umassmed.edu/oapubs/4295 Creative Commons License This work is licensed under a Creative Commons Attribution 4.0 License. This material is brought to you by eScholarship@UMMS. It has been accepted for inclusion in Open Access Articles by an authorized administrator of eScholarship@UMMS. For more information, please contact Lisa.Palmer@umassmed.edu. Concise CommunicationAddressing decontaminated respirators: Some methods appear todamage mask integrity and protective functionRichard E. Peltier PhD1 , Jiayuan Wang PhD1, Brian L. Hollenbeck MD2, Jennifer Lanza2, Ryan M. Furtado2,Jay Cyr MSN3, Richard T. Ellison MD3 and Kimiyoshi J. Kobayashi MD31University of Massachusetts, Amherst, Massachusetts, 2New England Baptist Hospital, Boston, Massachusetts and 3UMass Memorial Medical Center, Worcester,MassachusettsAbstractDecontamination of N95 respirators is being used by clinicians in the face of a global shortage of these devices. Some treatments for decon-tamination, such as some vaporized hydrogen peroxide methods or ultraviolet methods, had no impact on respiratory performance, whileother treatments resulted in substantial damage to masks.(Received 24 May 2020; accepted 3 July 2020)Frontline clinicians rely on the availability of personal protectionequipment (PPE), such as N95 respirators, to reduce the risk ofpersonal infection from exposure to respiratory droplets frominfected individuals. The rise of a global coronavirus disease2019 (COVID-19) pandemic has disrupted clinical supply chainsthat provide PPE, resulting in sustained shortages of N95 respira-tors, in part because of the widespread nature of the pandemic andthe degree to which infected patients can present with variedsymptoms.1 In an attempt to ameliorate this shortage, the USFood and Drug Administration issued an Emergency UseAuthorization that allowed decontamination techniques for N95respirators.2 This decision did not include mandate for furtherperformance testing of respirators.Several institutions have proposed the use of decontaminationtechniques to allow reuse of N95 respirators. Battelle has deployeda series of custom-designed vaporized hydrogen peroxide (vHP)sterilizers across the country.3 Others have proposed the use of dif-ferent methods, such as gas plasma hydrogen peroxide (gpHP) orultraviolet germicidal irradiation (UVGI) treatments. This meth-odology has eased the shortages of respirators, but an open ques-tion remains: Do respirators continue to protect a wearer afterdecontamination?To assess post-decontamination efficacy, some institutionsemploy tests such as quantitative fit testing. Respirator perfor-mance is more complex than maintaining fit, and there remainsa risk that fundamental aspects of respirators are degraded in away that limits their performance, even though they retain accept-able fit parameters. Notably, N952 is narrowly defined as a filteringmaterial that is capable of filtering 95% of 300-nm particles and islargely agnostic to other particle types or sizes. Because respiratorydroplets are expelled in a wide spectrum of sizes, typically rangingfrom 100 nm to 50 μm or more in diameter4 and because theypersist in the environment for several minutes,5 respirators mustbe effective across a range of potential conditions to provideprotection.Given the global N95 shortages, clinicians face a choice: wearinga used, and potentially contaminated respirator, or wearing a res-pirator that was decontaminated through a process that may affectthe integrity of the respirator. An urgent need exists to understandthe quantitative effects on respirator filtration with the use of thesetechniques so that wearers remain protected.MethodsN95 respirators were obtained from hospitals actively using vari-ous decontamination techniques, and respirators were donned ona mannequin that was covered in a layer of soft closed-cell foam.The mannequin was installed in a 0.1-m3 exposure chamber andflooded with polydispersed combustion aerosol. For this study,almost all respirators were 3M 1860 or 1860S models (3M, StPaul, MN). Air was sampled through the mask at 85 L/min andalternated between chamber and mask-occluded sampling, consis-tent with a method in our prior work.6 Aerosol samples were deliv-ered to a scanning mobility particle sizer (model 3225/3080, TSI,Minneapolis, MN), which characterized particle size distributionfrom 16.8 nm to 650 nm and provides much more detailed respi-rator performance information than standard filtration efficiencytesting. Incense was burned in a separate combustion chamber anddiluted ~50× prior to delivery to the exposure chamber. Usingincense aerosol is a more protective assessment because respiratorsare less effective at capturing combustion aerosol7 compared tosodium chloride.Author for correspondence: Richard E. Peltier, E-mail: rpeltier@umass.edu.Cite this article: Peltier RE, et al. (2020). Addressing decontaminated respirators: Somemethods appear to damage mask integrity and protective function. Infection Control &Hospital Epidemiology, https://doi.org/10.1017/ice.2020.332© 2020 by The Society for Healthcare Epidemiology of America. All rights reserved. This is an Open Access article, distributed under the terms of the Creative Commons Attributionlicence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.Infection Control & Hospital Epidemiology (2020), 1–3doi:10.1017/ice.2020.332Downloaded from https://www.cambridge.org/core. 13 Aug 2020 at 16:45:28, subject to the Cambridge Core terms of use.Respirator decontamination was performed off site using stan-dard hospital processing protocols, and the quantity of masks waslimited. The related data are summarized in Table 1.ResultsRespirators were characterized by filtration efficiency, which is aratio of particles that are immobilized by a respirator relative toconcentrations in the chamber. For each mask, this ratio is calcu-lated for each of 107 different measured particle sizes.Figure 1 shows filtration efficiency across measured particlesizes across a spectrum from 16.8 nm to 650 nm. Experimentalerror was estimated at 5%; thus, when a particular mask wasobserved to filter 90% or more particles at 300 nm, it was deemedconsistent with performance as a N95 respirator (Fig. 1a). Otherrespirators that do not meet this threshold were deemed inconsis-tent with this protection and are included in Figure 1b.Respirators that were treated with vHP, or shorter decontami-nation cycles of gpHP, retained their original filtration capabilities.These included Battelle Critical Care Decontamination System(CCDS) and Bioquell (both processed just once), or Sterrad100NX Express (processed up to 5 times). Steris V-Max Pro pro-duced similar results; respirators maintained their filtrationefficiency up to 10 treatments. Most ultraviolet treatments hadminimal impact on respirator performance.In contrast, gpHP treatment (by Sterrad 100S or Sterrad 100NXstandard) degrades respirator filtration performance, with sub-stantially decreased collection efficiencies across the entire size dis-tribution. UVGI appears to degrade respirator performance after 9repeated cycles.Table 1. Decontamination Treatments Evaluated This Study, Including the Number of Respirators Evaluated and the Number of TreatmentsTechniqueTrade Name and SpecificCyclesNo. of RespiratorsTestedCycle or Dwell Time(min)Repeated DecontaminationTreatmentsGas plasma HP Sterrad 100S 1 55 1xSterrad 100NX Express 5 28 1x, 3x, 5xSterrad 100NX Standard 1 47 1xVaporized HP Battelle CCDS 1 150 1xBioquell 2 Varies 1xSteris V-Pro Max II 10 28 1x through 10xUltraviolet germicidalirradiationSurfacide 10 10 (per side) 1x through 10x10% diluted bleach N/A 6 10 1x, 5xNote. gpHP, gas-plasma hydrogen peroxide; vHP, vaporized hydrogen peroxide; UV, ultraviolet germicidal irradiation.Fig. 1. Filtration efficiency of N95 respirators across different decontamination treatments. (a) Plot on left includes masks where efficiency was >90% at 300 nm, andreflects a well-functioning mask. (b) Plot on right represents other decontamination methods where performance appears degraded. Dashed horizontal and verticallines intersect at 300 nm and 95%, which is the basis for N95 designation. Shaded region indicates 95% confidence interval of the smoothed fit. In 1b, KN95, NXStandard, and Bandana efficiency are <50% at 150 nm, and it is not shown for clarity.2 Richard E. Peltier et alDownloaded from https://www.cambridge.org/core. 13 Aug 2020 at 16:45:28, subject to the Cambridge Core terms of use.For comparison, a KN95 mask (Dongguan Huagang), and a4-ply polyester bandana are included in Figure 1. Neither weretreated with any decontamination, with filtration efficiencies muchworse than all masks in Figure 1a. We also evaluated performanceof a N95 respirator that was immersed in a 0.5% bleach solution(Fig. 1b), and performance was also degraded.DiscussionRespirator performance can vary greatly. Respirators are surpris-ingly complex matrixes that can be deleteriously impacted byexternal forces, such as damaging interaction with strongly oxidiz-ing environments. Although the intent of decontamination is tofurnish a sanitized respirator for clinical reuse, some treatmentsresult in respirators that offer less protection to wearers.Although the evidence presented here are limited, there aresome generalizable conclusion that can be drawn. Treatments thatinvolve hydrogen peroxide and gas plasma at high concentrations(Sterrad 100NX Standard, concentration, ~90%), or long dwelltimes (Sterrad 100S) appear to induce damage to masks.Repeated UVGI processing appears to slowly diminish filtrationefficiency, and this diminished efficacy reaches a level that war-rants caution after ~9 repeated treatments. However, the Sterrad100NX express cycle, which uses a lower concentration of gpHPand shorter time, has limited impact on respirator performancefor up to 5 cycles. Our results are consistent with recent findings.8,9Ou et al10 also tested UVGI with results consistent to those shownhere, but their methods, which were quite similar to ours, providedmore granular details on filtration performance than typicalfiltration efficiency testing.In general, vHP appears to have less of a deleterious impact onrespirator performance. Treatments involving vHP include SterisV-Pro Max (tested up to 10 repeated decontaminations) andBioquell and Battelle CCDS (tested after only 1 decontaminationcycle). We cannot draw any conclusions about whether repeatedBioquell or Battelle CCDS treatments were acceptable becausewe were unable to source sufficient respirators.The results of this study do not address fit or general respiratorintegrity, which are also important for proper respirator function.For any respirator decontamination, respirator integrity should beassessed (including elastic function or corrosion on staples), and fittesting should be performed before use.These results suggest that respirators continue to perform asexpected when decontaminated, mainly by vHP, UVGI, or briefexposures to gpHP. Future studies could explore whether use ofdecontaminated respirators is linked to healthcare workeroutbreaks as another potential indicator of respirator performance.Decontamination treatments need to be carefully considered byclinical staff, especially for decontamination methods not yet wellunderstood, in the search for creative ways to provide sufficientrespirators to clinical staff.Acknowledgments. The funders had no role in study design, data collectionand analysis, decision to publish, or preparation of the manuscript. Any opin-ions, findings, and conclusions or recommendations expressed in this materialare those of the authors and do not necessarily reflect the views of the NationalScience Foundation.Financial support. These findings are based upon work supported by theNational Science Foundation (grant no. 2028589 to R.E.P.).Conflicts of interest. The authors declare no competing interests exist.References1. Wang D, Ju XL, Xie F, et al. Clinical analysis of 31 cases of 2019 novel coro-navirus infection in children from six provinces (autonomous region) ofnorthern China. Chin J Pediatrics 2020;58:269–274.2. Government US. Code of Federal Regulations. Vol 1910.1342020.3. Ostriker R. Boston hospitals getting ‘game changer’ machine that sterilizes80,000 protective masks a day. Boston Globe website. https://www.bostonglobe.com/2020/04/02/metro/boston-hospitals-getting-game-changer-machine-that-sterilizes-80000-protective-masks-day/. Published April 2, 2020.Accessed July 10, 2020.4. Holmgren H, Ljungström E, Almstrand A-C, Bake B, Olin A-C. Size distri-bution of exhaled particles in the range from 0.01 to 2.0 μm. J Aerosol Sci2010;41:439–446.5. Stadnytskyi V, Bax CE, Bax A, Anfinrud P. The airborne lifetime of smallspeech droplets and their potential importance in SARS-CoV-2 transmis-sion. Proc Nat Acad Sci 2020;117:11875–11877.6. Shakya KM, Noyes A, Kallin R, Peltier RE. Evaluating the efficacy of clothfacemasks in reducing particulate matter exposure. J Expo Sci EnvironEpidemiol 2017;27:352–357.7. Gao S, Kim J, Yermakov M, et al. Performance of N95 FFRs against com-bustion and NaCl aerosols in dry andmoderately humid air: manikin-basedstudy. Ann Occupat Hygiene 2016;60:748–760.8. Liao L, Xiao W, Zhao M, et al. Can N95 respirators be reused after disin-fection? How many times? ACS Nano 2020;14:6348–6356.9. Lin TH, Chen CC, Huang SH, Kuo CW, Lai CY, Lin WY. Filter quality ofelectret masks in filtering 14.6–594-nm aerosol particles: effects of fivedecontamination methods. Plos One 2017;12:e0186217.10. Ou Q, Pei C, Kim SC, Abell E, Pui DY. Evaluation of decontaminationmethods for commercial and alternative respirator and mask materials–view from filtration aspect. J Aerosol Sci 2020:105609. doi: 10.1016/j.jaerosci.2020.105609.Infection Control & Hospital Epidemiology 3Downloaded from https://www.cambridge.org/core. 13 Aug 2020 at 16:45:28, subject to the Cambridge Core terms of use.

Addressing decontaminated respirators: Some methods appear to damage mask integrity and protective function

ScholarWorks@UMass Amherst

University of Massachusetts Amherst ScholarWorks@UMass Amherst Environmental Health Sciences Faculty Publication Series Environmental Health Sciences 2020 Addressing decontaminated respirators: Some methods appear to damage mask integrity and protective function Richard E. Peltier Jiayuan Wang Brian L. Hollenbeck Jennifer Lanza Ryan M. Furtado See next page for additional authors Follow this and additional works at: https://scholarworks.umass.edu/ehs_faculty_pubs  Part of the Other Medicine and Health Sciences Commons Authors Richard E. Peltier, Jiayuan Wang, Brian L. Hollenbeck, Jennifer Lanza, Ryan M. Furtado, Jay Cyr, Richard T. Ellison, and Kimiyoshi J. Kobayashi Concise CommunicationAddressing decontaminated respirators: Some methods appear todamage mask integrity and protective functionRichard E. Peltier PhD1 , Jiayuan Wang PhD1, Brian L. Hollenbeck MD2, Jennifer Lanza2, Ryan M. Furtado2,Jay Cyr MSN3, Richard T. Ellison MD3 and Kimiyoshi J. Kobayashi MD31University of Massachusetts, Amherst, Massachusetts, 2New England Baptist Hospital, Boston, Massachusetts and 3UMass Memorial Medical Center, Worcester,MassachusettsAbstractDecontamination of N95 respirators is being used by clinicians in the face of a global shortage of these devices. Some treatments for decon-tamination, such as some vaporized hydrogen peroxide methods or ultraviolet methods, had no impact on respiratory performance, whileother treatments resulted in substantial damage to masks.(Received 24 May 2020; accepted 3 July 2020; electronically published 16 July 2020)Frontline clinicians rely on the availability of personal protectionequipment (PPE), such as N95 respirators, to reduce the risk ofpersonal infection from exposure to respiratory droplets frominfected individuals. The rise of a global coronavirus disease2019 (COVID-19) pandemic has disrupted clinical supply chainsthat provide PPE, resulting in sustained shortages of N95 respira-tors, in part because of the widespread nature of the pandemic andthe degree to which infected patients can present with variedsymptoms.1 In an attempt to ameliorate this shortage, the USFood and Drug Administration issued an Emergency UseAuthorization that allowed decontamination techniques for N95respirators.2 This decision did not include mandate for furtherperformance testing of respirators.Several institutions have proposed the use of decontaminationtechniques to allow reuse of N95 respirators. Battelle has deployeda series of custom-designed vaporized hydrogen peroxide (vHP)sterilizers across the country.3 Others have proposed the use of dif-ferent methods, such as gas plasma hydrogen peroxide (gpHP) orultraviolet germicidal irradiation (UVGI) treatments. This meth-odology has eased the shortages of respirators, but an open ques-tion remains: Do respirators continue to protect a wearer afterdecontamination?To assess post-decontamination efficacy, some institutionsemploy tests such as quantitative fit testing. Respirator perfor-mance is more complex than maintaining fit, and there remainsa risk that fundamental aspects of respirators are degraded in away that limits their performance, even though they retain accept-able fit parameters. Notably, N952 is narrowly defined as a filteringmaterial that is capable of filtering 95% of 300-nm particles and islargely agnostic to other particle types or sizes. Because respiratorydroplets are expelled in a wide spectrum of sizes, typically rangingfrom 100 nm to 50 μm or more in diameter4 and because theypersist in the environment for several minutes,5 respirators mustbe effective across a range of potential conditions to provideprotection.Given the global N95 shortages, clinicians face a choice: wearinga used, and potentially contaminated respirator, or wearing a res-pirator that was decontaminated through a process that may affectthe integrity of the respirator. An urgent need exists to understandthe quantitative effects on respirator filtration with the use of thesetechniques so that wearers remain protected.MethodsN95 respirators were obtained from hospitals actively using vari-ous decontamination techniques, and respirators were donned ona mannequin that was covered in a layer of soft closed-cell foam.The mannequin was installed in a 0.1-m3 exposure chamber andflooded with polydispersed combustion aerosol. For this study,almost all respirators were 3M 1860 or 1860S models (3M, StPaul, MN). Air was sampled through the mask at 85 L/min andalternated between chamber and mask-occluded sampling, consis-tent with a method in our prior work.6 Aerosol samples were deliv-ered to a scanning mobility particle sizer (model 3225/3080, TSI,Minneapolis, MN), which characterized particle size distributionfrom 16.8 nm to 650 nm and provides much more detailed respi-rator performance information than standard filtration efficiencytesting. Incense was burned in a separate combustion chamber anddiluted ~50× prior to delivery to the exposure chamber. Usingincense aerosol is a more protective assessment because respiratorsare less effective at capturing combustion aerosol7 compared tosodium chloride.Author for correspondence: Richard E. Peltier, E-mail: rpeltier@umass.edu.Cite this article: Peltier RE, et al. (2020). Addressing decontaminated respirators: Somemethods appear to damage mask integrity and protective function. Infection Control &Hospital Epidemiology, 41: 1446–1448, https://doi.org/10.1017/ice.2020.332© 2020 by The Society for Healthcare Epidemiology of America. All rights reserved. This is an Open Access article, distributed under the terms of the Creative Commons Attributionlicence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.Infection Control & Hospital Epidemiology (2020), 41, 1446–1448doi:10.1017/ice.2020.332Downloaded from https://www.cambridge.org/core. 28 Sep 2021 at 20:17:04, subject to the Cambridge Core terms of use.Respirator decontamination was performed off site using stan-dard hospital processing protocols, and the quantity of masks waslimited. The related data are summarized in Table 1.ResultsRespirators were characterized by filtration efficiency, which is aratio of particles that are immobilized by a respirator relative toconcentrations in the chamber. For each mask, this ratio is calcu-lated for each of 107 different measured particle sizes.Figure 1 shows filtration efficiency across measured particlesizes across a spectrum from 16.8 nm to 650 nm. Experimentalerror was estimated at 5%; thus, when a particular mask wasobserved to filter 90% or more particles at 300 nm, it was deemedconsistent with performance as a N95 respirator (Fig. 1a). Otherrespirators that do not meet this threshold were deemed inconsis-tent with this protection and are included in Figure 1b.Respirators that were treated with vHP, or shorter decontami-nation cycles of gpHP, retained their original filtration capabilities.These included Battelle Critical Care Decontamination System(CCDS) and Bioquell (both processed just once), or Sterrad100NX Express (processed up to 5 times). Steris V-Max Pro pro-duced similar results; respirators maintained their filtrationefficiency up to 10 treatments. Most ultraviolet treatments hadminimal impact on respirator performance.In contrast, gpHP treatment (by Sterrad 100S or Sterrad 100NXstandard) degrades respirator filtration performance, with sub-stantially decreased collection efficiencies across the entire size dis-tribution. UVGI appears to degrade respirator performance after 9repeated cycles.Table 1. Decontamination Treatments Evaluated This Study, Including the Number of Respirators Evaluated and the Number of TreatmentsTechniqueTrade Name and SpecificCyclesNo. of RespiratorsTestedCycle or Dwell Time(min)Repeated DecontaminationTreatmentsGas plasma HP Sterrad 100S 1 55 1xSterrad 100NX Express 5 28 1x, 3x, 5xSterrad 100NX Standard 1 47 1xVaporized HP Battelle CCDS 1 150 1xBioquell 2 Varies 1xSteris V-Pro Max II 10 28 1x through 10xUltraviolet germicidalirradiationSurfacide 10 10 (per side) 1x through 10x10% diluted bleach N/A 6 10 1x, 5xNote. gpHP, gas-plasma hydrogen peroxide; vHP, vaporized hydrogen peroxide; UV, ultraviolet germicidal irradiation.Fig. 1. Filtration efficiency of N95 respirators across different decontamination treatments. (a) Plot on left includes masks where efficiency was>90% at 300 nm, andreflects a well-functioning mask. (b) Plot on right represents other decontamination methods where performance appears degraded. Dashed horizontal and verticallines intersect at 300 nm and 95%, which is the basis for N95 designation. Shaded region indicates 95% confidence interval of the smoothed fit. In 1b, KN95, NXStandard, and Bandana efficiency are <50% at 150 nm, and it is not shown for clarity.Infection Control & Hospital Epidemiology 1447Downloaded from https://www.cambridge.org/core. 28 Sep 2021 at 20:17:04, subject to the Cambridge Core terms of use.For comparison, a KN95 mask (Dongguan Huagang), and a4-ply polyester bandana are included in Figure 1. Neither weretreated with any decontamination, with filtration efficiencies muchworse than all masks in Figure 1a. We also evaluated performanceof a N95 respirator that was immersed in a 0.5% bleach solution(Fig. 1b), and performance was also degraded.DiscussionRespirator performance can vary greatly. Respirators are surpris-ingly complex matrixes that can be deleteriously impacted byexternal forces, such as damaging interaction with strongly oxidiz-ing environments. Although the intent of decontamination is tofurnish a sanitized respirator for clinical reuse, some treatmentsresult in respirators that offer less protection to wearers.Although the evidence presented here are limited, there aresome generalizable conclusion that can be drawn. Treatments thatinvolve hydrogen peroxide and gas plasma at high concentrations(Sterrad 100NX Standard, concentration, ~90%), or long dwelltimes (Sterrad 100S) appear to induce damage to masks.Repeated UVGI processing appears to slowly diminish filtrationefficiency, and this diminished efficacy reaches a level that war-rants caution after ~9 repeated treatments. However, the Sterrad100NX express cycle, which uses a lower concentration of gpHPand shorter time, has limited impact on respirator performancefor up to 5 cycles. Our results are consistent with recent findings.8,9Ou et al10 also tested UVGI with results consistent to those shownhere, but their methods, which were quite similar to ours, providedmore granular details on filtration performance than typicalfiltration efficiency testing.In general, vHP appears to have less of a deleterious impact onrespirator performance. Treatments involving vHP include SterisV-Pro Max (tested up to 10 repeated decontaminations) andBioquell and Battelle CCDS (tested after only 1 decontaminationcycle). We cannot draw any conclusions about whether repeatedBioquell or Battelle CCDS treatments were acceptable becausewe were unable to source sufficient respirators.The results of this study do not address fit or general respiratorintegrity, which are also important for proper respirator function.For any respirator decontamination, respirator integrity should beassessed (including elastic function or corrosion on staples), and fittesting should be performed before use.These results suggest that respirators continue to perform asexpected when decontaminated, mainly by vHP, UVGI, or briefexposures to gpHP. Future studies could explore whether use ofdecontaminated respirators is linked to healthcare workeroutbreaks as another potential indicator of respirator performance.Decontamination treatments need to be carefully considered byclinical staff, especially for decontamination methods not yet wellunderstood, in the search for creative ways to provide sufficientrespirators to clinical staff.Acknowledgments. The funders had no role in study design, data collectionand analysis, decision to publish, or preparation of the manuscript. Any opin-ions, findings, and conclusions or recommendations expressed in this materialare those of the authors and do not necessarily reflect the views of the NationalScience Foundation.Financial support. These findings are based upon work supported by theNational Science Foundation (grant no. 2028589 to R.E.P.).Conflicts of interest. The authors declare no competing interests exist.References1. Wang D, Ju XL, Xie F, et al. Clinical analysis of 31 cases of 2019 novel coro-navirus infection in children from six provinces (autonomous region) ofnorthern China. Chin J Pediatrics 2020;58:269–274.2. Government US. Code of Federal Regulations. Vol 1910.1342020.3. Ostriker R. Boston hospitals getting ‘game changer’ machine that sterilizes80,000 protective masks a day. Boston Globe website. https://www.bostonglobe.com/2020/04/02/metro/boston-hospitals-getting-game-changer-machine-that-sterilizes-80000-protective-masks-day/. Published April 2, 2020.Accessed July 10, 2020.4. Holmgren H, Ljungström E, Almstrand A-C, Bake B, Olin A-C. Size distri-bution of exhaled particles in the range from 0.01 to 2.0 μm. J Aerosol Sci2010;41:439–446.5. Stadnytskyi V, Bax CE, Bax A, Anfinrud P. The airborne lifetime of smallspeech droplets and their potential importance in SARS-CoV-2 transmis-sion. Proc Nat Acad Sci 2020;117:11875–11877.6. Shakya KM, Noyes A, Kallin R, Peltier RE. Evaluating the efficacy of clothfacemasks in reducing particulate matter exposure. J Expo Sci EnvironEpidemiol 2017;27:352–357.7. Gao S, Kim J, Yermakov M, et al. Performance of N95 FFRs against com-bustion and NaCl aerosols in dry andmoderately humid air: manikin-basedstudy. Ann Occupat Hygiene 2016;60:748–760.8. Liao L, Xiao W, Zhao M, et al. Can N95 respirators be reused after disin-fection? How many times? ACS Nano 2020;14:6348–6356.9. Lin TH, Chen CC, Huang SH, Kuo CW, Lai CY, Lin WY. Filter quality ofelectret masks in filtering 14.6–594-nm aerosol particles: effects of fivedecontamination methods. Plos One 2017;12:e0186217.10. Ou Q, Pei C, Kim SC, Abell E, Pui DY. Evaluation of decontaminationmethods for commercial and alternative respirator and mask materials–view from filtration aspect. J Aerosol Sci 2020:105609. doi: 10.1016/j.jaerosci.2020.105609.1448 Richard E. Peltier et alDownloaded from https://www.cambridge.org/core. 28 Sep 2021 at 20:17:04, subject to the Cambridge Core terms of use.

https://escholarship.umassmed.edu/cgi/viewcontent.cgi?article=5321&context=oapubs

Addressing decontaminated respirators: Some methods appear to damage mask integrity and protective function

Abstract

Similar works

Full text

Available Versions

eScholarship@UMMS

ScholarWorks@UMass Amherst