Abstract
Discussion Forum (0)
ePoster
Topic: COVID-19 - Infection Prevention and Control
O'Hearn, Katharine1; Gertsman, Shira1; Sampson, Margaret2; Webster, Richard3; Tsampalieros, Anne3; Ng, Rhiannon1; Gibson, Jess1; Lobos, Anna-Theresa4; Acharya, Nina5; Agarwal, Anirudh6;
Boggs, Samantha4; Chamberlain, Graham4; Staykov, Emiliyan7; Sikora, Lindsey8; and McNally, James Dayre1,4
1 Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
2 Library Services, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
3 Clinical Research Unit, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
4 Department of Pediatrics, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
5 Michael G. DeGroote School of Medicine, McMaster University
6 Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
7 Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
8 Health Sciences Library, University of Ottawa, Ottawa, Ontario, Canada
Children's Hospital of Eastern Ontario Research Institute
Introduction/Background:
Inadequate supply of filtering facepiece respirators (FFR) for healthcare workers during a pandemic such as the novel coronavirus outbreak (SARS-CoV-2) is a serious issue. A potential solution to extending the supply of existing FFRs would be to decontaminate and re-use N95 FFRs.
Objectives:
To help inform FFR-reuse policies and procedures, this systematic review synthesized existing data on the effectiveness of ultraviolet germicidal irradiation (UVGI) for N95 FFR decontamination, with the following specific objectives: (1) to assess the impact of UVGI on FFR performance, with a specific focus on aerosol penetration and airflow resistance; (2) to determine the effectiveness of UVGI at removing viral or bacterial load; and (3) to describe measures or observations related to fit or physical degradation following UVGI exposure.
Methods:
This was a systematic review (PROSPERO CRD42020176156) on UVGI decontamination of N95 FFRs using Embase, Medline, Global Health, Google Scholar, WHO COVID-19 feed, and MedRxiv. Records (n = 1111) were uploaded to insightScope screening software (www.insightscope.ca), a web-based platform that allows creation of a large, online team to facilitate rapid citation screening. Citation screening and data extraction were performed in duplicate by two, independent reviewers over an accelerated timeline of three days. Original research reporting on N95 FFR function, decontamination, mask fit or changes in physical traits following UVGI were included.
Results:
Thirteen studies were identified1-13, comprising 54 UVGI intervention arms and 58 N95 models. FFRs consistently maintained National Institute for Occupational Safety and Health (NIOSH) certification standards following UVGI. Aerosol penetration averaged 1.19% (0.70-2.48%) and 1.14% (0.57-2.63%) for control and UVGI arms respectively (NIOSH Standard: <5%14). Airflow resistance for the control arms averaged 9.79 mm H2O (7.97-11.70 mm H2O) vs 9.85 mm H2O (8.33-11.44 mm H2O) for UVGI arms (NIOSH Standard: <25mm H2O15). UVGI protocols employing a cumulative dose >20,000 J/m2 resulted in a 2-log reduction in viral load. A >3 log
reduction was observed in seven UVGI arms using >40,000 J/m2. Impact of UVGI on FFR fit was evaluated in two studies and did not find evidence of compromise following a single8 or three cycles5 of UVGI (cumulative doses of 32,400 and 16,200 J/m2 respectively). There were no significant changes in physical appearance, texture or odor to any mask model following a single cycle or three cycles of UVGI exposure.
Conclusion:
The function of N95 masks, based on aerosol penetration and airflow filtration, is maintained following a single cycle of UVGI. Decontamination using UV light in the laboratory setting suggests that this can be a successful method of removing viral pathogens from FFRs. Future studies should use a cumulative UV-C dose of 40,000 J/m2 and focus on determining the impact of UVGI on mask fit in the real-world setting, as well as the maximum number of UVGI cycles that can be safely applied to an N95 FFR.
Image 1
Image 2
Image 3
1 Fisher, E. M. & Shaffer, R. E. A method to determine the available UV-C dose for the decontamination of filtering facepiece respirators. Journal of Applied Microbiology 110, 287-295, doi:10.1111/j.1365-2672.2010.04881.x (2010).
2 Heimbuch, B. K. et al. A pandemic influenza preparedness study: use of energetic methods to decontaminate filtering facepiece respirators contaminated with H1N1 aerosols and droplets. American Journal of Infection Control 39, e1-9, doi:https://dx.doi.org/10.1016/j.ajic.2010.07.004 (2011).
3 Lin, T. H., Tang, F. C., Hung, P. C., Hua, Z. C. & Lai, C. Y. Relative survival of Bacillus subtilis spores loaded on filtering facepiece respirators after five decontamination methods. Indoor Air 31, 31, doi:https://dx.doi.org/10.1111/ina.12475 (2018).
4 Lindsley, W. G. et al. Effects of Ultraviolet Germicidal Irradiation (UVGI) on N95 Respirator Filtration Performance and Structural Integrity. J Occup Environ Hyg 12, 509-517, doi:https://dx.doi.org/10.1080/15459624.2015.1018518 (2015).
5 Bergman, M. S., Viscusi, D. J., Palmiero, A. J., Powell, J. B. & Shaffer, R. E. Impact of Three Cycles of Decontamination Treatments on Filtering Facepiece Respirator Fit. Journal of the International Society for Respiratory Protection 28, 48-59 (2011).
6 Mills, D., Harnish, D. A., Lawrence, C., Sandoval-Powers, M. & Heimbuch, B. K. Ultraviolet germicidal irradiation of influenza-contaminated N95 filtering facepiece respirators. American Journal of Infection Control 46, e49-e55, doi:https://dx.doi.org/10.1016/j.ajic.2018.02.018 (2018).
7 Viscusi, D. J., Bergman, M. S., Eimer, B. C. & Shaffer, R. E. Evaluation of five decontamination methods for filtering facepiece respirators. Annals of Occupational Hygiene 53, 815-827, doi:https://dx.doi.org/10.1093/annhyg/mep070 (2009).
8 Viscusi, D. J. et al. Impact of three biological decontamination methods on filtering facepiece respirator fit, odor, comfort, and donning ease. Journal of Occupational and Environmental Hygiene 8, 426-436, doi:10.1080/15459624.2011.585927 (2011).
9 Viscusi, D. J., King, W. P. & Shaffer, R. E. Effect of Decontamination on the Filtration Efficiency of Two Filtering Facepiece Respirator Models. Journal of the International Society for Respiratory Protection 24, 93-106 (2007).
10 Vo, E., Rengasamy, S. & Shaffer, R. Development of a test system to evaluate procedures for decontamination of respirators containing viral droplets. Appl Environ Microbiol 75, 7303-7309, doi:https://dx.doi.org/10.1128/AEM.00799-09 (2009).
11 Woo, M. H., Grippin, A., Anwar, D. & Smith, T. Effects of relative humidity and spraying medium on UV decontamination of filters loaded with viral aerosols. Appl. Environ … (2012).
12 Lore, M. B., Heimbuch, B. K., Brown, T. L., Wander, J. D. & Hinrichs, S. H. Effectiveness of three decontamination treatments against influenza virus applied to filtering facepiece respirators. Annals of Occupational Hygiene 56, 92-101, doi:https://dx.doi.org/10.1093/annhyg/mer054 (2012).
13 Bergman, M. S. et al. Evaluation of Multiple (3-Cycle) Decontamination Processing for Filtering Facepiece Respirators. Journal of Engineered Fibers and Fabrics 5, 33-41 (2010).
14 National Institute for Occupational Safety and Health. NIOSH Guide to the Selection and Use of Particulate Respirators, <https://www.cdc.gov/niosh/docs/96-101/default.html> (1996).
Topic: COVID-19 - Infection Prevention and Control
O'Hearn, Katharine1; Gertsman, Shira1; Sampson, Margaret2; Webster, Richard3; Tsampalieros, Anne3; Ng, Rhiannon1; Gibson, Jess1; Lobos, Anna-Theresa4; Acharya, Nina5; Agarwal, Anirudh6;
Boggs, Samantha4; Chamberlain, Graham4; Staykov, Emiliyan7; Sikora, Lindsey8; and McNally, James Dayre1,4
1 Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
2 Library Services, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
3 Clinical Research Unit, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
4 Department of Pediatrics, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
5 Michael G. DeGroote School of Medicine, McMaster University
6 Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
7 Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
8 Health Sciences Library, University of Ottawa, Ottawa, Ontario, Canada
Children's Hospital of Eastern Ontario Research Institute
Introduction/Background:
Inadequate supply of filtering facepiece respirators (FFR) for healthcare workers during a pandemic such as the novel coronavirus outbreak (SARS-CoV-2) is a serious issue. A potential solution to extending the supply of existing FFRs would be to decontaminate and re-use N95 FFRs.
Objectives:
To help inform FFR-reuse policies and procedures, this systematic review synthesized existing data on the effectiveness of ultraviolet germicidal irradiation (UVGI) for N95 FFR decontamination, with the following specific objectives: (1) to assess the impact of UVGI on FFR performance, with a specific focus on aerosol penetration and airflow resistance; (2) to determine the effectiveness of UVGI at removing viral or bacterial load; and (3) to describe measures or observations related to fit or physical degradation following UVGI exposure.
Methods:
This was a systematic review (PROSPERO CRD42020176156) on UVGI decontamination of N95 FFRs using Embase, Medline, Global Health, Google Scholar, WHO COVID-19 feed, and MedRxiv. Records (n = 1111) were uploaded to insightScope screening software (www.insightscope.ca), a web-based platform that allows creation of a large, online team to facilitate rapid citation screening. Citation screening and data extraction were performed in duplicate by two, independent reviewers over an accelerated timeline of three days. Original research reporting on N95 FFR function, decontamination, mask fit or changes in physical traits following UVGI were included.
Results:
Thirteen studies were identified1-13, comprising 54 UVGI intervention arms and 58 N95 models. FFRs consistently maintained National Institute for Occupational Safety and Health (NIOSH) certification standards following UVGI. Aerosol penetration averaged 1.19% (0.70-2.48%) and 1.14% (0.57-2.63%) for control and UVGI arms respectively (NIOSH Standard: <5%14). Airflow resistance for the control arms averaged 9.79 mm H2O (7.97-11.70 mm H2O) vs 9.85 mm H2O (8.33-11.44 mm H2O) for UVGI arms (NIOSH Standard: <25mm H2O15). UVGI protocols employing a cumulative dose >20,000 J/m2 resulted in a 2-log reduction in viral load. A >3 log
reduction was observed in seven UVGI arms using >40,000 J/m2. Impact of UVGI on FFR fit was evaluated in two studies and did not find evidence of compromise following a single8 or three cycles5 of UVGI (cumulative doses of 32,400 and 16,200 J/m2 respectively). There were no significant changes in physical appearance, texture or odor to any mask model following a single cycle or three cycles of UVGI exposure.
Conclusion:
The function of N95 masks, based on aerosol penetration and airflow filtration, is maintained following a single cycle of UVGI. Decontamination using UV light in the laboratory setting suggests that this can be a successful method of removing viral pathogens from FFRs. Future studies should use a cumulative UV-C dose of 40,000 J/m2 and focus on determining the impact of UVGI on mask fit in the real-world setting, as well as the maximum number of UVGI cycles that can be safely applied to an N95 FFR.
Image 1
Image 2
Image 3
1 Fisher, E. M. & Shaffer, R. E. A method to determine the available UV-C dose for the decontamination of filtering facepiece respirators. Journal of Applied Microbiology 110, 287-295, doi:10.1111/j.1365-2672.2010.04881.x (2010).
2 Heimbuch, B. K. et al. A pandemic influenza preparedness study: use of energetic methods to decontaminate filtering facepiece respirators contaminated with H1N1 aerosols and droplets. American Journal of Infection Control 39, e1-9, doi:https://dx.doi.org/10.1016/j.ajic.2010.07.004 (2011).
3 Lin, T. H., Tang, F. C., Hung, P. C., Hua, Z. C. & Lai, C. Y. Relative survival of Bacillus subtilis spores loaded on filtering facepiece respirators after five decontamination methods. Indoor Air 31, 31, doi:https://dx.doi.org/10.1111/ina.12475 (2018).
4 Lindsley, W. G. et al. Effects of Ultraviolet Germicidal Irradiation (UVGI) on N95 Respirator Filtration Performance and Structural Integrity. J Occup Environ Hyg 12, 509-517, doi:https://dx.doi.org/10.1080/15459624.2015.1018518 (2015).
5 Bergman, M. S., Viscusi, D. J., Palmiero, A. J., Powell, J. B. & Shaffer, R. E. Impact of Three Cycles of Decontamination Treatments on Filtering Facepiece Respirator Fit. Journal of the International Society for Respiratory Protection 28, 48-59 (2011).
6 Mills, D., Harnish, D. A., Lawrence, C., Sandoval-Powers, M. & Heimbuch, B. K. Ultraviolet germicidal irradiation of influenza-contaminated N95 filtering facepiece respirators. American Journal of Infection Control 46, e49-e55, doi:https://dx.doi.org/10.1016/j.ajic.2018.02.018 (2018).
7 Viscusi, D. J., Bergman, M. S., Eimer, B. C. & Shaffer, R. E. Evaluation of five decontamination methods for filtering facepiece respirators. Annals of Occupational Hygiene 53, 815-827, doi:https://dx.doi.org/10.1093/annhyg/mep070 (2009).
8 Viscusi, D. J. et al. Impact of three biological decontamination methods on filtering facepiece respirator fit, odor, comfort, and donning ease. Journal of Occupational and Environmental Hygiene 8, 426-436, doi:10.1080/15459624.2011.585927 (2011).
9 Viscusi, D. J., King, W. P. & Shaffer, R. E. Effect of Decontamination on the Filtration Efficiency of Two Filtering Facepiece Respirator Models. Journal of the International Society for Respiratory Protection 24, 93-106 (2007).
10 Vo, E., Rengasamy, S. & Shaffer, R. Development of a test system to evaluate procedures for decontamination of respirators containing viral droplets. Appl Environ Microbiol 75, 7303-7309, doi:https://dx.doi.org/10.1128/AEM.00799-09 (2009).
11 Woo, M. H., Grippin, A., Anwar, D. & Smith, T. Effects of relative humidity and spraying medium on UV decontamination of filters loaded with viral aerosols. Appl. Environ … (2012).
12 Lore, M. B., Heimbuch, B. K., Brown, T. L., Wander, J. D. & Hinrichs, S. H. Effectiveness of three decontamination treatments against influenza virus applied to filtering facepiece respirators. Annals of Occupational Hygiene 56, 92-101, doi:https://dx.doi.org/10.1093/annhyg/mer054 (2012).
13 Bergman, M. S. et al. Evaluation of Multiple (3-Cycle) Decontamination Processing for Filtering Facepiece Respirators. Journal of Engineered Fibers and Fabrics 5, 33-41 (2010).
14 National Institute for Occupational Safety and Health. NIOSH Guide to the Selection and Use of Particulate Respirators, <https://www.cdc.gov/niosh/docs/96-101/default.html> (1996).
15 U.S. Government Publishing Office. Airflow Resistance Tests, <https://www.ecfr.gov/cgibin/textidx?SID=5b2666d4940f00b38d815af01a2e7044&mc=true&node=pt42.1.84&rgn=div5#se42.1.84_1180> (1999).
ePoster
Topic: COVID-19 - Infection Prevention and Control
O'Hearn, Katharine1; Gertsman, Shira1; Sampson, Margaret2; Webster, Richard3; Tsampalieros, Anne3; Ng, Rhiannon1; Gibson, Jess1; Lobos, Anna-Theresa4; Acharya, Nina5; Agarwal, Anirudh6;
Boggs, Samantha4; Chamberlain, Graham4; Staykov, Emiliyan7; Sikora, Lindsey8; and McNally, James Dayre1,4
1 Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
2 Library Services, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
3 Clinical Research Unit, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
4 Department of Pediatrics, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
5 Michael G. DeGroote School of Medicine, McMaster University
6 Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
7 Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
8 Health Sciences Library, University of Ottawa, Ottawa, Ontario, Canada
Children's Hospital of Eastern Ontario Research Institute
Introduction/Background:
Inadequate supply of filtering facepiece respirators (FFR) for healthcare workers during a pandemic such as the novel coronavirus outbreak (SARS-CoV-2) is a serious issue. A potential solution to extending the supply of existing FFRs would be to decontaminate and re-use N95 FFRs.
Objectives:
To help inform FFR-reuse policies and procedures, this systematic review synthesized existing data on the effectiveness of ultraviolet germicidal irradiation (UVGI) for N95 FFR decontamination, with the following specific objectives: (1) to assess the impact of UVGI on FFR performance, with a specific focus on aerosol penetration and airflow resistance; (2) to determine the effectiveness of UVGI at removing viral or bacterial load; and (3) to describe measures or observations related to fit or physical degradation following UVGI exposure.
Methods:
This was a systematic review (PROSPERO CRD42020176156) on UVGI decontamination of N95 FFRs using Embase, Medline, Global Health, Google Scholar, WHO COVID-19 feed, and MedRxiv. Records (n = 1111) were uploaded to insightScope screening software (www.insightscope.ca), a web-based platform that allows creation of a large, online team to facilitate rapid citation screening. Citation screening and data extraction were performed in duplicate by two, independent reviewers over an accelerated timeline of three days. Original research reporting on N95 FFR function, decontamination, mask fit or changes in physical traits following UVGI were included.
Results:
Thirteen studies were identified1-13, comprising 54 UVGI intervention arms and 58 N95 models. FFRs consistently maintained National Institute for Occupational Safety and Health (NIOSH) certification standards following UVGI. Aerosol penetration averaged 1.19% (0.70-2.48%) and 1.14% (0.57-2.63%) for control and UVGI arms respectively (NIOSH Standard: <5%14). Airflow resistance for the control arms averaged 9.79 mm H2O (7.97-11.70 mm H2O) vs 9.85 mm H2O (8.33-11.44 mm H2O) for UVGI arms (NIOSH Standard: <25mm H2O15). UVGI protocols employing a cumulative dose >20,000 J/m2 resulted in a 2-log reduction in viral load. A >3 log
reduction was observed in seven UVGI arms using >40,000 J/m2. Impact of UVGI on FFR fit was evaluated in two studies and did not find evidence of compromise following a single8 or three cycles5 of UVGI (cumulative doses of 32,400 and 16,200 J/m2 respectively). There were no significant changes in physical appearance, texture or odor to any mask model following a single cycle or three cycles of UVGI exposure.
Conclusion:
The function of N95 masks, based on aerosol penetration and airflow filtration, is maintained following a single cycle of UVGI. Decontamination using UV light in the laboratory setting suggests that this can be a successful method of removing viral pathogens from FFRs. Future studies should use a cumulative UV-C dose of 40,000 J/m2 and focus on determining the impact of UVGI on mask fit in the real-world setting, as well as the maximum number of UVGI cycles that can be safely applied to an N95 FFR.
Image 1
Image 2
Image 3
1 Fisher, E. M. & Shaffer, R. E. A method to determine the available UV-C dose for the decontamination of filtering facepiece respirators. Journal of Applied Microbiology 110, 287-295, doi:10.1111/j.1365-2672.2010.04881.x (2010).
2 Heimbuch, B. K. et al. A pandemic influenza preparedness study: use of energetic methods to decontaminate filtering facepiece respirators contaminated with H1N1 aerosols and droplets. American Journal of Infection Control 39, e1-9, doi:https://dx.doi.org/10.1016/j.ajic.2010.07.004 (2011).
3 Lin, T. H., Tang, F. C., Hung, P. C., Hua, Z. C. & Lai, C. Y. Relative survival of Bacillus subtilis spores loaded on filtering facepiece respirators after five decontamination methods. Indoor Air 31, 31, doi:https://dx.doi.org/10.1111/ina.12475 (2018).
4 Lindsley, W. G. et al. Effects of Ultraviolet Germicidal Irradiation (UVGI) on N95 Respirator Filtration Performance and Structural Integrity. J Occup Environ Hyg 12, 509-517, doi:https://dx.doi.org/10.1080/15459624.2015.1018518 (2015).
5 Bergman, M. S., Viscusi, D. J., Palmiero, A. J., Powell, J. B. & Shaffer, R. E. Impact of Three Cycles of Decontamination Treatments on Filtering Facepiece Respirator Fit. Journal of the International Society for Respiratory Protection 28, 48-59 (2011).
6 Mills, D., Harnish, D. A., Lawrence, C., Sandoval-Powers, M. & Heimbuch, B. K. Ultraviolet germicidal irradiation of influenza-contaminated N95 filtering facepiece respirators. American Journal of Infection Control 46, e49-e55, doi:https://dx.doi.org/10.1016/j.ajic.2018.02.018 (2018).
7 Viscusi, D. J., Bergman, M. S., Eimer, B. C. & Shaffer, R. E. Evaluation of five decontamination methods for filtering facepiece respirators. Annals of Occupational Hygiene 53, 815-827, doi:https://dx.doi.org/10.1093/annhyg/mep070 (2009).
8 Viscusi, D. J. et al. Impact of three biological decontamination methods on filtering facepiece respirator fit, odor, comfort, and donning ease. Journal of Occupational and Environmental Hygiene 8, 426-436, doi:10.1080/15459624.2011.585927 (2011).
9 Viscusi, D. J., King, W. P. & Shaffer, R. E. Effect of Decontamination on the Filtration Efficiency of Two Filtering Facepiece Respirator Models. Journal of the International Society for Respiratory Protection 24, 93-106 (2007).
10 Vo, E., Rengasamy, S. & Shaffer, R. Development of a test system to evaluate procedures for decontamination of respirators containing viral droplets. Appl Environ Microbiol 75, 7303-7309, doi:https://dx.doi.org/10.1128/AEM.00799-09 (2009).
11 Woo, M. H., Grippin, A., Anwar, D. & Smith, T. Effects of relative humidity and spraying medium on UV decontamination of filters loaded with viral aerosols. Appl. Environ … (2012).
12 Lore, M. B., Heimbuch, B. K., Brown, T. L., Wander, J. D. & Hinrichs, S. H. Effectiveness of three decontamination treatments against influenza virus applied to filtering facepiece respirators. Annals of Occupational Hygiene 56, 92-101, doi:https://dx.doi.org/10.1093/annhyg/mer054 (2012).
13 Bergman, M. S. et al. Evaluation of Multiple (3-Cycle) Decontamination Processing for Filtering Facepiece Respirators. Journal of Engineered Fibers and Fabrics 5, 33-41 (2010).
14 National Institute for Occupational Safety and Health. NIOSH Guide to the Selection and Use of Particulate Respirators, <https://www.cdc.gov/niosh/docs/96-101/default.html> (1996).
Topic: COVID-19 - Infection Prevention and Control
O'Hearn, Katharine1; Gertsman, Shira1; Sampson, Margaret2; Webster, Richard3; Tsampalieros, Anne3; Ng, Rhiannon1; Gibson, Jess1; Lobos, Anna-Theresa4; Acharya, Nina5; Agarwal, Anirudh6;
Boggs, Samantha4; Chamberlain, Graham4; Staykov, Emiliyan7; Sikora, Lindsey8; and McNally, James Dayre1,4
1 Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
2 Library Services, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
3 Clinical Research Unit, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
4 Department of Pediatrics, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
5 Michael G. DeGroote School of Medicine, McMaster University
6 Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
7 Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
8 Health Sciences Library, University of Ottawa, Ottawa, Ontario, Canada
Children's Hospital of Eastern Ontario Research Institute
Introduction/Background:
Inadequate supply of filtering facepiece respirators (FFR) for healthcare workers during a pandemic such as the novel coronavirus outbreak (SARS-CoV-2) is a serious issue. A potential solution to extending the supply of existing FFRs would be to decontaminate and re-use N95 FFRs.
Objectives:
To help inform FFR-reuse policies and procedures, this systematic review synthesized existing data on the effectiveness of ultraviolet germicidal irradiation (UVGI) for N95 FFR decontamination, with the following specific objectives: (1) to assess the impact of UVGI on FFR performance, with a specific focus on aerosol penetration and airflow resistance; (2) to determine the effectiveness of UVGI at removing viral or bacterial load; and (3) to describe measures or observations related to fit or physical degradation following UVGI exposure.
Methods:
This was a systematic review (PROSPERO CRD42020176156) on UVGI decontamination of N95 FFRs using Embase, Medline, Global Health, Google Scholar, WHO COVID-19 feed, and MedRxiv. Records (n = 1111) were uploaded to insightScope screening software (www.insightscope.ca), a web-based platform that allows creation of a large, online team to facilitate rapid citation screening. Citation screening and data extraction were performed in duplicate by two, independent reviewers over an accelerated timeline of three days. Original research reporting on N95 FFR function, decontamination, mask fit or changes in physical traits following UVGI were included.
Results:
Thirteen studies were identified1-13, comprising 54 UVGI intervention arms and 58 N95 models. FFRs consistently maintained National Institute for Occupational Safety and Health (NIOSH) certification standards following UVGI. Aerosol penetration averaged 1.19% (0.70-2.48%) and 1.14% (0.57-2.63%) for control and UVGI arms respectively (NIOSH Standard: <5%14). Airflow resistance for the control arms averaged 9.79 mm H2O (7.97-11.70 mm H2O) vs 9.85 mm H2O (8.33-11.44 mm H2O) for UVGI arms (NIOSH Standard: <25mm H2O15). UVGI protocols employing a cumulative dose >20,000 J/m2 resulted in a 2-log reduction in viral load. A >3 log
reduction was observed in seven UVGI arms using >40,000 J/m2. Impact of UVGI on FFR fit was evaluated in two studies and did not find evidence of compromise following a single8 or three cycles5 of UVGI (cumulative doses of 32,400 and 16,200 J/m2 respectively). There were no significant changes in physical appearance, texture or odor to any mask model following a single cycle or three cycles of UVGI exposure.
Conclusion:
The function of N95 masks, based on aerosol penetration and airflow filtration, is maintained following a single cycle of UVGI. Decontamination using UV light in the laboratory setting suggests that this can be a successful method of removing viral pathogens from FFRs. Future studies should use a cumulative UV-C dose of 40,000 J/m2 and focus on determining the impact of UVGI on mask fit in the real-world setting, as well as the maximum number of UVGI cycles that can be safely applied to an N95 FFR.
Image 1
Image 2
Image 3
1 Fisher, E. M. & Shaffer, R. E. A method to determine the available UV-C dose for the decontamination of filtering facepiece respirators. Journal of Applied Microbiology 110, 287-295, doi:10.1111/j.1365-2672.2010.04881.x (2010).
2 Heimbuch, B. K. et al. A pandemic influenza preparedness study: use of energetic methods to decontaminate filtering facepiece respirators contaminated with H1N1 aerosols and droplets. American Journal of Infection Control 39, e1-9, doi:https://dx.doi.org/10.1016/j.ajic.2010.07.004 (2011).
3 Lin, T. H., Tang, F. C., Hung, P. C., Hua, Z. C. & Lai, C. Y. Relative survival of Bacillus subtilis spores loaded on filtering facepiece respirators after five decontamination methods. Indoor Air 31, 31, doi:https://dx.doi.org/10.1111/ina.12475 (2018).
4 Lindsley, W. G. et al. Effects of Ultraviolet Germicidal Irradiation (UVGI) on N95 Respirator Filtration Performance and Structural Integrity. J Occup Environ Hyg 12, 509-517, doi:https://dx.doi.org/10.1080/15459624.2015.1018518 (2015).
5 Bergman, M. S., Viscusi, D. J., Palmiero, A. J., Powell, J. B. & Shaffer, R. E. Impact of Three Cycles of Decontamination Treatments on Filtering Facepiece Respirator Fit. Journal of the International Society for Respiratory Protection 28, 48-59 (2011).
6 Mills, D., Harnish, D. A., Lawrence, C., Sandoval-Powers, M. & Heimbuch, B. K. Ultraviolet germicidal irradiation of influenza-contaminated N95 filtering facepiece respirators. American Journal of Infection Control 46, e49-e55, doi:https://dx.doi.org/10.1016/j.ajic.2018.02.018 (2018).
7 Viscusi, D. J., Bergman, M. S., Eimer, B. C. & Shaffer, R. E. Evaluation of five decontamination methods for filtering facepiece respirators. Annals of Occupational Hygiene 53, 815-827, doi:https://dx.doi.org/10.1093/annhyg/mep070 (2009).
8 Viscusi, D. J. et al. Impact of three biological decontamination methods on filtering facepiece respirator fit, odor, comfort, and donning ease. Journal of Occupational and Environmental Hygiene 8, 426-436, doi:10.1080/15459624.2011.585927 (2011).
9 Viscusi, D. J., King, W. P. & Shaffer, R. E. Effect of Decontamination on the Filtration Efficiency of Two Filtering Facepiece Respirator Models. Journal of the International Society for Respiratory Protection 24, 93-106 (2007).
10 Vo, E., Rengasamy, S. & Shaffer, R. Development of a test system to evaluate procedures for decontamination of respirators containing viral droplets. Appl Environ Microbiol 75, 7303-7309, doi:https://dx.doi.org/10.1128/AEM.00799-09 (2009).
11 Woo, M. H., Grippin, A., Anwar, D. & Smith, T. Effects of relative humidity and spraying medium on UV decontamination of filters loaded with viral aerosols. Appl. Environ … (2012).
12 Lore, M. B., Heimbuch, B. K., Brown, T. L., Wander, J. D. & Hinrichs, S. H. Effectiveness of three decontamination treatments against influenza virus applied to filtering facepiece respirators. Annals of Occupational Hygiene 56, 92-101, doi:https://dx.doi.org/10.1093/annhyg/mer054 (2012).
13 Bergman, M. S. et al. Evaluation of Multiple (3-Cycle) Decontamination Processing for Filtering Facepiece Respirators. Journal of Engineered Fibers and Fabrics 5, 33-41 (2010).
14 National Institute for Occupational Safety and Health. NIOSH Guide to the Selection and Use of Particulate Respirators, <https://www.cdc.gov/niosh/docs/96-101/default.html> (1996).
15 U.S. Government Publishing Office. Airflow Resistance Tests, <https://www.ecfr.gov/cgibin/textidx?SID=5b2666d4940f00b38d815af01a2e7044&mc=true&node=pt42.1.84&rgn=div5#se42.1.84_1180> (1999).
Decontaminating N95 and SN95 masks with Ultraviolet Germicidal Irradiation (UVGI) does not impair mask efficacy and safety: A Systematic Decontaminating N95 and SN95 Masks with Ultraviolet Germicidal Irradiation (UVGI) Does Not Impair Mask Efficacy and Safety: A Systematic Review
James Dayre McNally
Abstract
Discussion Forum (0)
ePoster
Topic: COVID-19 - Infection Prevention and Control
O'Hearn, Katharine1; Gertsman, Shira1; Sampson, Margaret2; Webster, Richard3; Tsampalieros, Anne3; Ng, Rhiannon1; Gibson, Jess1; Lobos, Anna-Theresa4; Acharya, Nina5; Agarwal, Anirudh6;
Boggs, Samantha4; Chamberlain, Graham4; Staykov, Emiliyan7; Sikora, Lindsey8; and McNally, James Dayre1,4
1 Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
2 Library Services, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
3 Clinical Research Unit, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
4 Department of Pediatrics, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
5 Michael G. DeGroote School of Medicine, McMaster University
6 Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
7 Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
8 Health Sciences Library, University of Ottawa, Ottawa, Ontario, Canada
Children's Hospital of Eastern Ontario Research Institute
Introduction/Background:
Inadequate supply of filtering facepiece respirators (FFR) for healthcare workers during a pandemic such as the novel coronavirus outbreak (SARS-CoV-2) is a serious issue. A potential solution to extending the supply of existing FFRs would be to decontaminate and re-use N95 FFRs.
Objectives:
To help inform FFR-reuse policies and procedures, this systematic review synthesized existing data on the effectiveness of ultraviolet germicidal irradiation (UVGI) for N95 FFR decontamination, with the following specific objectives: (1) to assess the impact of UVGI on FFR performance, with a specific focus on aerosol penetration and airflow resistance; (2) to determine the effectiveness of UVGI at removing viral or bacterial load; and (3) to describe measures or observations related to fit or physical degradation following UVGI exposure.
Methods:
This was a systematic review (PROSPERO CRD42020176156) on UVGI decontamination of N95 FFRs using Embase, Medline, Global Health, Google Scholar, WHO COVID-19 feed, and MedRxiv. Records (n = 1111) were uploaded to insightScope screening software (www.insightscope.ca), a web-based platform that allows creation of a large, online team to facilitate rapid citation screening. Citation screening and data extraction were performed in duplicate by two, independent reviewers over an accelerated timeline of three days. Original research reporting on N95 FFR function, decontamination, mask fit or changes in physical traits following UVGI were included.
Results:
Thirteen studies were identified1-13, comprising 54 UVGI intervention arms and 58 N95 models. FFRs consistently maintained National Institute for Occupational Safety and Health (NIOSH) certification standards following UVGI. Aerosol penetration averaged 1.19% (0.70-2.48%) and 1.14% (0.57-2.63%) for control and UVGI arms respectively (NIOSH Standard: <5%14). Airflow resistance for the control arms averaged 9.79 mm H2O (7.97-11.70 mm H2O) vs 9.85 mm H2O (8.33-11.44 mm H2O) for UVGI arms (NIOSH Standard: <25mm H2O15). UVGI protocols employing a cumulative dose >20,000 J/m2 resulted in a 2-log reduction in viral load. A >3 log
reduction was observed in seven UVGI arms using >40,000 J/m2. Impact of UVGI on FFR fit was evaluated in two studies and did not find evidence of compromise following a single8 or three cycles5 of UVGI (cumulative doses of 32,400 and 16,200 J/m2 respectively). There were no significant changes in physical appearance, texture or odor to any mask model following a single cycle or three cycles of UVGI exposure.
Conclusion:
The function of N95 masks, based on aerosol penetration and airflow filtration, is maintained following a single cycle of UVGI. Decontamination using UV light in the laboratory setting suggests that this can be a successful method of removing viral pathogens from FFRs. Future studies should use a cumulative UV-C dose of 40,000 J/m2 and focus on determining the impact of UVGI on mask fit in the real-world setting, as well as the maximum number of UVGI cycles that can be safely applied to an N95 FFR.
Image 1
Image 2
Image 3
1 Fisher, E. M. & Shaffer, R. E. A method to determine the available UV-C dose for the decontamination of filtering facepiece respirators. Journal of Applied Microbiology 110, 287-295, doi:10.1111/j.1365-2672.2010.04881.x (2010).
2 Heimbuch, B. K. et al. A pandemic influenza preparedness study: use of energetic methods to decontaminate filtering facepiece respirators contaminated with H1N1 aerosols and droplets. American Journal of Infection Control 39, e1-9, doi:https://dx.doi.org/10.1016/j.ajic.2010.07.004 (2011).
3 Lin, T. H., Tang, F. C., Hung, P. C., Hua, Z. C. & Lai, C. Y. Relative survival of Bacillus subtilis spores loaded on filtering facepiece respirators after five decontamination methods. Indoor Air 31, 31, doi:https://dx.doi.org/10.1111/ina.12475 (2018).
4 Lindsley, W. G. et al. Effects of Ultraviolet Germicidal Irradiation (UVGI) on N95 Respirator Filtration Performance and Structural Integrity. J Occup Environ Hyg 12, 509-517, doi:https://dx.doi.org/10.1080/15459624.2015.1018518 (2015).
5 Bergman, M. S., Viscusi, D. J., Palmiero, A. J., Powell, J. B. & Shaffer, R. E. Impact of Three Cycles of Decontamination Treatments on Filtering Facepiece Respirator Fit. Journal of the International Society for Respiratory Protection 28, 48-59 (2011).
6 Mills, D., Harnish, D. A., Lawrence, C., Sandoval-Powers, M. & Heimbuch, B. K. Ultraviolet germicidal irradiation of influenza-contaminated N95 filtering facepiece respirators. American Journal of Infection Control 46, e49-e55, doi:https://dx.doi.org/10.1016/j.ajic.2018.02.018 (2018).
7 Viscusi, D. J., Bergman, M. S., Eimer, B. C. & Shaffer, R. E. Evaluation of five decontamination methods for filtering facepiece respirators. Annals of Occupational Hygiene 53, 815-827, doi:https://dx.doi.org/10.1093/annhyg/mep070 (2009).
8 Viscusi, D. J. et al. Impact of three biological decontamination methods on filtering facepiece respirator fit, odor, comfort, and donning ease. Journal of Occupational and Environmental Hygiene 8, 426-436, doi:10.1080/15459624.2011.585927 (2011).
9 Viscusi, D. J., King, W. P. & Shaffer, R. E. Effect of Decontamination on the Filtration Efficiency of Two Filtering Facepiece Respirator Models. Journal of the International Society for Respiratory Protection 24, 93-106 (2007).
10 Vo, E., Rengasamy, S. & Shaffer, R. Development of a test system to evaluate procedures for decontamination of respirators containing viral droplets. Appl Environ Microbiol 75, 7303-7309, doi:https://dx.doi.org/10.1128/AEM.00799-09 (2009).
11 Woo, M. H., Grippin, A., Anwar, D. & Smith, T. Effects of relative humidity and spraying medium on UV decontamination of filters loaded with viral aerosols. Appl. Environ … (2012).
12 Lore, M. B., Heimbuch, B. K., Brown, T. L., Wander, J. D. & Hinrichs, S. H. Effectiveness of three decontamination treatments against influenza virus applied to filtering facepiece respirators. Annals of Occupational Hygiene 56, 92-101, doi:https://dx.doi.org/10.1093/annhyg/mer054 (2012).
13 Bergman, M. S. et al. Evaluation of Multiple (3-Cycle) Decontamination Processing for Filtering Facepiece Respirators. Journal of Engineered Fibers and Fabrics 5, 33-41 (2010).
14 National Institute for Occupational Safety and Health. NIOSH Guide to the Selection and Use of Particulate Respirators, <https://www.cdc.gov/niosh/docs/96-101/default.html> (1996).
Topic: COVID-19 - Infection Prevention and Control
O'Hearn, Katharine1; Gertsman, Shira1; Sampson, Margaret2; Webster, Richard3; Tsampalieros, Anne3; Ng, Rhiannon1; Gibson, Jess1; Lobos, Anna-Theresa4; Acharya, Nina5; Agarwal, Anirudh6;
Boggs, Samantha4; Chamberlain, Graham4; Staykov, Emiliyan7; Sikora, Lindsey8; and McNally, James Dayre1,4
1 Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
2 Library Services, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
3 Clinical Research Unit, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
4 Department of Pediatrics, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
5 Michael G. DeGroote School of Medicine, McMaster University
6 Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
7 Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
8 Health Sciences Library, University of Ottawa, Ottawa, Ontario, Canada
Children's Hospital of Eastern Ontario Research Institute
Introduction/Background:
Inadequate supply of filtering facepiece respirators (FFR) for healthcare workers during a pandemic such as the novel coronavirus outbreak (SARS-CoV-2) is a serious issue. A potential solution to extending the supply of existing FFRs would be to decontaminate and re-use N95 FFRs.
Objectives:
To help inform FFR-reuse policies and procedures, this systematic review synthesized existing data on the effectiveness of ultraviolet germicidal irradiation (UVGI) for N95 FFR decontamination, with the following specific objectives: (1) to assess the impact of UVGI on FFR performance, with a specific focus on aerosol penetration and airflow resistance; (2) to determine the effectiveness of UVGI at removing viral or bacterial load; and (3) to describe measures or observations related to fit or physical degradation following UVGI exposure.
Methods:
This was a systematic review (PROSPERO CRD42020176156) on UVGI decontamination of N95 FFRs using Embase, Medline, Global Health, Google Scholar, WHO COVID-19 feed, and MedRxiv. Records (n = 1111) were uploaded to insightScope screening software (www.insightscope.ca), a web-based platform that allows creation of a large, online team to facilitate rapid citation screening. Citation screening and data extraction were performed in duplicate by two, independent reviewers over an accelerated timeline of three days. Original research reporting on N95 FFR function, decontamination, mask fit or changes in physical traits following UVGI were included.
Results:
Thirteen studies were identified1-13, comprising 54 UVGI intervention arms and 58 N95 models. FFRs consistently maintained National Institute for Occupational Safety and Health (NIOSH) certification standards following UVGI. Aerosol penetration averaged 1.19% (0.70-2.48%) and 1.14% (0.57-2.63%) for control and UVGI arms respectively (NIOSH Standard: <5%14). Airflow resistance for the control arms averaged 9.79 mm H2O (7.97-11.70 mm H2O) vs 9.85 mm H2O (8.33-11.44 mm H2O) for UVGI arms (NIOSH Standard: <25mm H2O15). UVGI protocols employing a cumulative dose >20,000 J/m2 resulted in a 2-log reduction in viral load. A >3 log
reduction was observed in seven UVGI arms using >40,000 J/m2. Impact of UVGI on FFR fit was evaluated in two studies and did not find evidence of compromise following a single8 or three cycles5 of UVGI (cumulative doses of 32,400 and 16,200 J/m2 respectively). There were no significant changes in physical appearance, texture or odor to any mask model following a single cycle or three cycles of UVGI exposure.
Conclusion:
The function of N95 masks, based on aerosol penetration and airflow filtration, is maintained following a single cycle of UVGI. Decontamination using UV light in the laboratory setting suggests that this can be a successful method of removing viral pathogens from FFRs. Future studies should use a cumulative UV-C dose of 40,000 J/m2 and focus on determining the impact of UVGI on mask fit in the real-world setting, as well as the maximum number of UVGI cycles that can be safely applied to an N95 FFR.
Image 1
Image 2
Image 3
1 Fisher, E. M. & Shaffer, R. E. A method to determine the available UV-C dose for the decontamination of filtering facepiece respirators. Journal of Applied Microbiology 110, 287-295, doi:10.1111/j.1365-2672.2010.04881.x (2010).
2 Heimbuch, B. K. et al. A pandemic influenza preparedness study: use of energetic methods to decontaminate filtering facepiece respirators contaminated with H1N1 aerosols and droplets. American Journal of Infection Control 39, e1-9, doi:https://dx.doi.org/10.1016/j.ajic.2010.07.004 (2011).
3 Lin, T. H., Tang, F. C., Hung, P. C., Hua, Z. C. & Lai, C. Y. Relative survival of Bacillus subtilis spores loaded on filtering facepiece respirators after five decontamination methods. Indoor Air 31, 31, doi:https://dx.doi.org/10.1111/ina.12475 (2018).
4 Lindsley, W. G. et al. Effects of Ultraviolet Germicidal Irradiation (UVGI) on N95 Respirator Filtration Performance and Structural Integrity. J Occup Environ Hyg 12, 509-517, doi:https://dx.doi.org/10.1080/15459624.2015.1018518 (2015).
5 Bergman, M. S., Viscusi, D. J., Palmiero, A. J., Powell, J. B. & Shaffer, R. E. Impact of Three Cycles of Decontamination Treatments on Filtering Facepiece Respirator Fit. Journal of the International Society for Respiratory Protection 28, 48-59 (2011).
6 Mills, D., Harnish, D. A., Lawrence, C., Sandoval-Powers, M. & Heimbuch, B. K. Ultraviolet germicidal irradiation of influenza-contaminated N95 filtering facepiece respirators. American Journal of Infection Control 46, e49-e55, doi:https://dx.doi.org/10.1016/j.ajic.2018.02.018 (2018).
7 Viscusi, D. J., Bergman, M. S., Eimer, B. C. & Shaffer, R. E. Evaluation of five decontamination methods for filtering facepiece respirators. Annals of Occupational Hygiene 53, 815-827, doi:https://dx.doi.org/10.1093/annhyg/mep070 (2009).
8 Viscusi, D. J. et al. Impact of three biological decontamination methods on filtering facepiece respirator fit, odor, comfort, and donning ease. Journal of Occupational and Environmental Hygiene 8, 426-436, doi:10.1080/15459624.2011.585927 (2011).
9 Viscusi, D. J., King, W. P. & Shaffer, R. E. Effect of Decontamination on the Filtration Efficiency of Two Filtering Facepiece Respirator Models. Journal of the International Society for Respiratory Protection 24, 93-106 (2007).
10 Vo, E., Rengasamy, S. & Shaffer, R. Development of a test system to evaluate procedures for decontamination of respirators containing viral droplets. Appl Environ Microbiol 75, 7303-7309, doi:https://dx.doi.org/10.1128/AEM.00799-09 (2009).
11 Woo, M. H., Grippin, A., Anwar, D. & Smith, T. Effects of relative humidity and spraying medium on UV decontamination of filters loaded with viral aerosols. Appl. Environ … (2012).
12 Lore, M. B., Heimbuch, B. K., Brown, T. L., Wander, J. D. & Hinrichs, S. H. Effectiveness of three decontamination treatments against influenza virus applied to filtering facepiece respirators. Annals of Occupational Hygiene 56, 92-101, doi:https://dx.doi.org/10.1093/annhyg/mer054 (2012).
13 Bergman, M. S. et al. Evaluation of Multiple (3-Cycle) Decontamination Processing for Filtering Facepiece Respirators. Journal of Engineered Fibers and Fabrics 5, 33-41 (2010).
14 National Institute for Occupational Safety and Health. NIOSH Guide to the Selection and Use of Particulate Respirators, <https://www.cdc.gov/niosh/docs/96-101/default.html> (1996).
15 U.S. Government Publishing Office. Airflow Resistance Tests, <https://www.ecfr.gov/cgibin/textidx?SID=5b2666d4940f00b38d815af01a2e7044&mc=true&node=pt42.1.84&rgn=div5#se42.1.84_1180> (1999).
ePoster
Topic: COVID-19 - Infection Prevention and Control
O'Hearn, Katharine1; Gertsman, Shira1; Sampson, Margaret2; Webster, Richard3; Tsampalieros, Anne3; Ng, Rhiannon1; Gibson, Jess1; Lobos, Anna-Theresa4; Acharya, Nina5; Agarwal, Anirudh6;
Boggs, Samantha4; Chamberlain, Graham4; Staykov, Emiliyan7; Sikora, Lindsey8; and McNally, James Dayre1,4
1 Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
2 Library Services, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
3 Clinical Research Unit, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
4 Department of Pediatrics, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
5 Michael G. DeGroote School of Medicine, McMaster University
6 Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
7 Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
8 Health Sciences Library, University of Ottawa, Ottawa, Ontario, Canada
Children's Hospital of Eastern Ontario Research Institute
Introduction/Background:
Inadequate supply of filtering facepiece respirators (FFR) for healthcare workers during a pandemic such as the novel coronavirus outbreak (SARS-CoV-2) is a serious issue. A potential solution to extending the supply of existing FFRs would be to decontaminate and re-use N95 FFRs.
Objectives:
To help inform FFR-reuse policies and procedures, this systematic review synthesized existing data on the effectiveness of ultraviolet germicidal irradiation (UVGI) for N95 FFR decontamination, with the following specific objectives: (1) to assess the impact of UVGI on FFR performance, with a specific focus on aerosol penetration and airflow resistance; (2) to determine the effectiveness of UVGI at removing viral or bacterial load; and (3) to describe measures or observations related to fit or physical degradation following UVGI exposure.
Methods:
This was a systematic review (PROSPERO CRD42020176156) on UVGI decontamination of N95 FFRs using Embase, Medline, Global Health, Google Scholar, WHO COVID-19 feed, and MedRxiv. Records (n = 1111) were uploaded to insightScope screening software (www.insightscope.ca), a web-based platform that allows creation of a large, online team to facilitate rapid citation screening. Citation screening and data extraction were performed in duplicate by two, independent reviewers over an accelerated timeline of three days. Original research reporting on N95 FFR function, decontamination, mask fit or changes in physical traits following UVGI were included.
Results:
Thirteen studies were identified1-13, comprising 54 UVGI intervention arms and 58 N95 models. FFRs consistently maintained National Institute for Occupational Safety and Health (NIOSH) certification standards following UVGI. Aerosol penetration averaged 1.19% (0.70-2.48%) and 1.14% (0.57-2.63%) for control and UVGI arms respectively (NIOSH Standard: <5%14). Airflow resistance for the control arms averaged 9.79 mm H2O (7.97-11.70 mm H2O) vs 9.85 mm H2O (8.33-11.44 mm H2O) for UVGI arms (NIOSH Standard: <25mm H2O15). UVGI protocols employing a cumulative dose >20,000 J/m2 resulted in a 2-log reduction in viral load. A >3 log
reduction was observed in seven UVGI arms using >40,000 J/m2. Impact of UVGI on FFR fit was evaluated in two studies and did not find evidence of compromise following a single8 or three cycles5 of UVGI (cumulative doses of 32,400 and 16,200 J/m2 respectively). There were no significant changes in physical appearance, texture or odor to any mask model following a single cycle or three cycles of UVGI exposure.
Conclusion:
The function of N95 masks, based on aerosol penetration and airflow filtration, is maintained following a single cycle of UVGI. Decontamination using UV light in the laboratory setting suggests that this can be a successful method of removing viral pathogens from FFRs. Future studies should use a cumulative UV-C dose of 40,000 J/m2 and focus on determining the impact of UVGI on mask fit in the real-world setting, as well as the maximum number of UVGI cycles that can be safely applied to an N95 FFR.
Image 1
Image 2
Image 3
1 Fisher, E. M. & Shaffer, R. E. A method to determine the available UV-C dose for the decontamination of filtering facepiece respirators. Journal of Applied Microbiology 110, 287-295, doi:10.1111/j.1365-2672.2010.04881.x (2010).
2 Heimbuch, B. K. et al. A pandemic influenza preparedness study: use of energetic methods to decontaminate filtering facepiece respirators contaminated with H1N1 aerosols and droplets. American Journal of Infection Control 39, e1-9, doi:https://dx.doi.org/10.1016/j.ajic.2010.07.004 (2011).
3 Lin, T. H., Tang, F. C., Hung, P. C., Hua, Z. C. & Lai, C. Y. Relative survival of Bacillus subtilis spores loaded on filtering facepiece respirators after five decontamination methods. Indoor Air 31, 31, doi:https://dx.doi.org/10.1111/ina.12475 (2018).
4 Lindsley, W. G. et al. Effects of Ultraviolet Germicidal Irradiation (UVGI) on N95 Respirator Filtration Performance and Structural Integrity. J Occup Environ Hyg 12, 509-517, doi:https://dx.doi.org/10.1080/15459624.2015.1018518 (2015).
5 Bergman, M. S., Viscusi, D. J., Palmiero, A. J., Powell, J. B. & Shaffer, R. E. Impact of Three Cycles of Decontamination Treatments on Filtering Facepiece Respirator Fit. Journal of the International Society for Respiratory Protection 28, 48-59 (2011).
6 Mills, D., Harnish, D. A., Lawrence, C., Sandoval-Powers, M. & Heimbuch, B. K. Ultraviolet germicidal irradiation of influenza-contaminated N95 filtering facepiece respirators. American Journal of Infection Control 46, e49-e55, doi:https://dx.doi.org/10.1016/j.ajic.2018.02.018 (2018).
7 Viscusi, D. J., Bergman, M. S., Eimer, B. C. & Shaffer, R. E. Evaluation of five decontamination methods for filtering facepiece respirators. Annals of Occupational Hygiene 53, 815-827, doi:https://dx.doi.org/10.1093/annhyg/mep070 (2009).
8 Viscusi, D. J. et al. Impact of three biological decontamination methods on filtering facepiece respirator fit, odor, comfort, and donning ease. Journal of Occupational and Environmental Hygiene 8, 426-436, doi:10.1080/15459624.2011.585927 (2011).
9 Viscusi, D. J., King, W. P. & Shaffer, R. E. Effect of Decontamination on the Filtration Efficiency of Two Filtering Facepiece Respirator Models. Journal of the International Society for Respiratory Protection 24, 93-106 (2007).
10 Vo, E., Rengasamy, S. & Shaffer, R. Development of a test system to evaluate procedures for decontamination of respirators containing viral droplets. Appl Environ Microbiol 75, 7303-7309, doi:https://dx.doi.org/10.1128/AEM.00799-09 (2009).
11 Woo, M. H., Grippin, A., Anwar, D. & Smith, T. Effects of relative humidity and spraying medium on UV decontamination of filters loaded with viral aerosols. Appl. Environ … (2012).
12 Lore, M. B., Heimbuch, B. K., Brown, T. L., Wander, J. D. & Hinrichs, S. H. Effectiveness of three decontamination treatments against influenza virus applied to filtering facepiece respirators. Annals of Occupational Hygiene 56, 92-101, doi:https://dx.doi.org/10.1093/annhyg/mer054 (2012).
13 Bergman, M. S. et al. Evaluation of Multiple (3-Cycle) Decontamination Processing for Filtering Facepiece Respirators. Journal of Engineered Fibers and Fabrics 5, 33-41 (2010).
14 National Institute for Occupational Safety and Health. NIOSH Guide to the Selection and Use of Particulate Respirators, <https://www.cdc.gov/niosh/docs/96-101/default.html> (1996).
Topic: COVID-19 - Infection Prevention and Control
O'Hearn, Katharine1; Gertsman, Shira1; Sampson, Margaret2; Webster, Richard3; Tsampalieros, Anne3; Ng, Rhiannon1; Gibson, Jess1; Lobos, Anna-Theresa4; Acharya, Nina5; Agarwal, Anirudh6;
Boggs, Samantha4; Chamberlain, Graham4; Staykov, Emiliyan7; Sikora, Lindsey8; and McNally, James Dayre1,4
1 Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
2 Library Services, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
3 Clinical Research Unit, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
4 Department of Pediatrics, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
5 Michael G. DeGroote School of Medicine, McMaster University
6 Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
7 Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
8 Health Sciences Library, University of Ottawa, Ottawa, Ontario, Canada
Children's Hospital of Eastern Ontario Research Institute
Introduction/Background:
Inadequate supply of filtering facepiece respirators (FFR) for healthcare workers during a pandemic such as the novel coronavirus outbreak (SARS-CoV-2) is a serious issue. A potential solution to extending the supply of existing FFRs would be to decontaminate and re-use N95 FFRs.
Objectives:
To help inform FFR-reuse policies and procedures, this systematic review synthesized existing data on the effectiveness of ultraviolet germicidal irradiation (UVGI) for N95 FFR decontamination, with the following specific objectives: (1) to assess the impact of UVGI on FFR performance, with a specific focus on aerosol penetration and airflow resistance; (2) to determine the effectiveness of UVGI at removing viral or bacterial load; and (3) to describe measures or observations related to fit or physical degradation following UVGI exposure.
Methods:
This was a systematic review (PROSPERO CRD42020176156) on UVGI decontamination of N95 FFRs using Embase, Medline, Global Health, Google Scholar, WHO COVID-19 feed, and MedRxiv. Records (n = 1111) were uploaded to insightScope screening software (www.insightscope.ca), a web-based platform that allows creation of a large, online team to facilitate rapid citation screening. Citation screening and data extraction were performed in duplicate by two, independent reviewers over an accelerated timeline of three days. Original research reporting on N95 FFR function, decontamination, mask fit or changes in physical traits following UVGI were included.
Results:
Thirteen studies were identified1-13, comprising 54 UVGI intervention arms and 58 N95 models. FFRs consistently maintained National Institute for Occupational Safety and Health (NIOSH) certification standards following UVGI. Aerosol penetration averaged 1.19% (0.70-2.48%) and 1.14% (0.57-2.63%) for control and UVGI arms respectively (NIOSH Standard: <5%14). Airflow resistance for the control arms averaged 9.79 mm H2O (7.97-11.70 mm H2O) vs 9.85 mm H2O (8.33-11.44 mm H2O) for UVGI arms (NIOSH Standard: <25mm H2O15). UVGI protocols employing a cumulative dose >20,000 J/m2 resulted in a 2-log reduction in viral load. A >3 log
reduction was observed in seven UVGI arms using >40,000 J/m2. Impact of UVGI on FFR fit was evaluated in two studies and did not find evidence of compromise following a single8 or three cycles5 of UVGI (cumulative doses of 32,400 and 16,200 J/m2 respectively). There were no significant changes in physical appearance, texture or odor to any mask model following a single cycle or three cycles of UVGI exposure.
Conclusion:
The function of N95 masks, based on aerosol penetration and airflow filtration, is maintained following a single cycle of UVGI. Decontamination using UV light in the laboratory setting suggests that this can be a successful method of removing viral pathogens from FFRs. Future studies should use a cumulative UV-C dose of 40,000 J/m2 and focus on determining the impact of UVGI on mask fit in the real-world setting, as well as the maximum number of UVGI cycles that can be safely applied to an N95 FFR.
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1 Fisher, E. M. & Shaffer, R. E. A method to determine the available UV-C dose for the decontamination of filtering facepiece respirators. Journal of Applied Microbiology 110, 287-295, doi:10.1111/j.1365-2672.2010.04881.x (2010).
2 Heimbuch, B. K. et al. A pandemic influenza preparedness study: use of energetic methods to decontaminate filtering facepiece respirators contaminated with H1N1 aerosols and droplets. American Journal of Infection Control 39, e1-9, doi:https://dx.doi.org/10.1016/j.ajic.2010.07.004 (2011).
3 Lin, T. H., Tang, F. C., Hung, P. C., Hua, Z. C. & Lai, C. Y. Relative survival of Bacillus subtilis spores loaded on filtering facepiece respirators after five decontamination methods. Indoor Air 31, 31, doi:https://dx.doi.org/10.1111/ina.12475 (2018).
4 Lindsley, W. G. et al. Effects of Ultraviolet Germicidal Irradiation (UVGI) on N95 Respirator Filtration Performance and Structural Integrity. J Occup Environ Hyg 12, 509-517, doi:https://dx.doi.org/10.1080/15459624.2015.1018518 (2015).
5 Bergman, M. S., Viscusi, D. J., Palmiero, A. J., Powell, J. B. & Shaffer, R. E. Impact of Three Cycles of Decontamination Treatments on Filtering Facepiece Respirator Fit. Journal of the International Society for Respiratory Protection 28, 48-59 (2011).
6 Mills, D., Harnish, D. A., Lawrence, C., Sandoval-Powers, M. & Heimbuch, B. K. Ultraviolet germicidal irradiation of influenza-contaminated N95 filtering facepiece respirators. American Journal of Infection Control 46, e49-e55, doi:https://dx.doi.org/10.1016/j.ajic.2018.02.018 (2018).
7 Viscusi, D. J., Bergman, M. S., Eimer, B. C. & Shaffer, R. E. Evaluation of five decontamination methods for filtering facepiece respirators. Annals of Occupational Hygiene 53, 815-827, doi:https://dx.doi.org/10.1093/annhyg/mep070 (2009).
8 Viscusi, D. J. et al. Impact of three biological decontamination methods on filtering facepiece respirator fit, odor, comfort, and donning ease. Journal of Occupational and Environmental Hygiene 8, 426-436, doi:10.1080/15459624.2011.585927 (2011).
9 Viscusi, D. J., King, W. P. & Shaffer, R. E. Effect of Decontamination on the Filtration Efficiency of Two Filtering Facepiece Respirator Models. Journal of the International Society for Respiratory Protection 24, 93-106 (2007).
10 Vo, E., Rengasamy, S. & Shaffer, R. Development of a test system to evaluate procedures for decontamination of respirators containing viral droplets. Appl Environ Microbiol 75, 7303-7309, doi:https://dx.doi.org/10.1128/AEM.00799-09 (2009).
11 Woo, M. H., Grippin, A., Anwar, D. & Smith, T. Effects of relative humidity and spraying medium on UV decontamination of filters loaded with viral aerosols. Appl. Environ … (2012).
12 Lore, M. B., Heimbuch, B. K., Brown, T. L., Wander, J. D. & Hinrichs, S. H. Effectiveness of three decontamination treatments against influenza virus applied to filtering facepiece respirators. Annals of Occupational Hygiene 56, 92-101, doi:https://dx.doi.org/10.1093/annhyg/mer054 (2012).
13 Bergman, M. S. et al. Evaluation of Multiple (3-Cycle) Decontamination Processing for Filtering Facepiece Respirators. Journal of Engineered Fibers and Fabrics 5, 33-41 (2010).
14 National Institute for Occupational Safety and Health. NIOSH Guide to the Selection and Use of Particulate Respirators, <https://www.cdc.gov/niosh/docs/96-101/default.html> (1996).
15 U.S. Government Publishing Office. Airflow Resistance Tests, <https://www.ecfr.gov/cgibin/textidx?SID=5b2666d4940f00b38d815af01a2e7044&mc=true&node=pt42.1.84&rgn=div5#se42.1.84_1180> (1999).
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