Decontamination of N95 masks for re-use employing 7 widely available sterilization methods

Kumar, Anand; Kasloff, Samantha; Leung, Anders; Cutts, Todd; Strong, James E.; Hills, Kevin; Gu, Frank; Chen, Paul; Vázquez-Grande, Gloria; Rush, Barret; Lother, Sylvain; Malo, Kimberly; Zarychanski, Ryan; Krishnan, Jay

doi:10.1371/journal.pone.0243965

Cited by 60 publications

(90 citation statements)

References 32 publications

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“…Considering the studies in the SLR’s final database, 31 studies [ 1 , 6 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 49 , 50 , 52 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 63 , 64 , 65 , 66 , 85 ], representing 53.45% of the SLR database, attest to UV-C’s germicidal capability, as they find results of at least 3-log reduction using different biological indicators, conditions, and setups. These studies present results using UV-C as a single method of sterilization.…”

Section: Uv-c’s Germicidal Capabilitymentioning

confidence: 99%

“…Ten publications [ 34 , 37 , 42 , 44 , 45 , 60 , 62 , 73 , 76 , 77 ] adapted machines/robots or used specific UVGI cabinets. These options seemed more expensive approaches than the previous ones.…”

Section: Uv-c’s Additional Advantagesmentioning

confidence: 99%

“…As the first potential problem (changes in integrity) already discards reprocessed SUPPE, we opted to leave it on Table 1 column “Changes in integrity or fit.” From our SLR database, 30 studies (51.72%) assess it, of which 21 [ 33 , 35 , 37 , 40 , 44 , 48 , 49 , 51 , 53 , 61 , 62 , 64 , 65 , 67 , 70 , 71 , 73 , 80 , 81 , 82 , 87 ] observe no physical changes within different rounds of sterilization or extenuating conditions. On the other hand, nine studies [ 36 , 38 , 42 , 47 , 54 , 75 , 78 , 84 , 86 ] find that masks or FFRs degraded, or faced changes in airflow resistance [ 36 , 47 , 75 , 78 ], or reached minimum acceptability levels after some rounds of reprocessing [ 38 , 42 , 54 , 84 , 86 ]. These results are important to consider, albeit with caution because one publication [ 78 ] indicates that despite having degradation problems, they varied according to the different models used, suggesting that it is wise to observe each case individually.…”

Section: Uv-c’s Disadvantagesmentioning

confidence: 99%

“…Another potential problem reprocessed masks and FFRs might present the reduction of their filtration power. Most studies [ 35 , 36 , 38 , 39 , 42 , 43 , 44 , 48 , 49 , 51 , 54 , 59 , 61 , 62 , 64 , 67 , 73 , 76 , 80 , 81 , 82 , 84 , 87 ] indicate that little or no effect happened as these SUPPE faced UV-C sterilization. However, this is not a consensus in the SLR’s final sample.…”

Section: Uv-c’s Disadvantagesmentioning

confidence: 99%

“…Only one [ 40 ] argued about the possibility of optimizing their system’s setup to cope with it. Nevertheless, an increase in dosage to reach deeper layers may lead to photooxidation on the surface [ 42 , 67 , 75 ]. Thus, better reflective setups and more uniform irradiation might prove to be better solutions to reach the inner layers.…”

Section: Uv-c’s Disadvantagesmentioning

confidence: 99%

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Ultraviolet-C as a Viable Reprocessing Method for Disposable Masks and Filtering Facepiece Respirators

2021

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In normal conditions, discarding single-use personal protective equipment after use is the rule for its users due to the possibility of being infected, particularly for masks and filtering facepiece respirators. When the demand for these protective tools is not satisfied by the companies supplying them, a scenario of shortages occurs, and new strategies must arise. One possible approach regards the disinfection of these pieces of equipment, but there are multiple methods. Analyzing these methods, Ultraviolet-C (UV-C) becomes an exciting option, given its germicidal capability. This paper aims to describe the state-of-the-art for UV-C sterilization in masks and filtering facepiece respirators. To achieve this goal, we adopted a systematic literature review in multiple databases added to a snowball method to make our sample as robust as possible and encompass a more significant number of studies. We found that UV-C’s germicidal capability is just as good as other sterilization methods. Combining this characteristic with other advantages makes UV-C sterilization desirable compared to other methods, despite its possible disadvantages.

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Section: Uv-c’s Germicidal Capabilitymentioning

confidence: 99%

Section: Uv-c’s Additional Advantagesmentioning

confidence: 99%

Section: Uv-c’s Disadvantagesmentioning

confidence: 99%

Section: Uv-c’s Disadvantagesmentioning

confidence: 99%

Section: Uv-c’s Disadvantagesmentioning

confidence: 99%

See 3 more Smart Citations

Ultraviolet-C as a Viable Reprocessing Method for Disposable Masks and Filtering Facepiece Respirators

2021

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Filtering Facepiece Respirator (N95 Respirator) Reprocessing

Schumm

Hadaya

Mody

et al. 2021

JAMA

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IMPORTANCE The COVID-19 pandemic has resulted in a persistent shortage of personal protective equipment; therefore, a need exists for hospitals to reprocess filtering facepiece respirators (FFRs), such as N95 respirators. OBJECTIVE To perform a systematic review to evaluate the evidence on effectiveness and feasibility of different processes used for decontaminating N95 respirators. EVIDENCE REVIEW A search of PubMed and EMBASE (through January 31, 2021) was completed for 5 types of respirator-decontaminating processes including UV irradiation, vaporized hydrogen peroxide, moist-heat incubation, microwave-generated steam, and ethylene oxide. Data were abstracted on process method, pathogen removal, mask filtration efficiency, facial fit, user safety, and processing capability. FINDINGS Forty-two studies were included that examined 65 total types of masks. All were laboratory studies (no clinical trials), and 2 evaluated respirator performance and fit with actual clinical use of N95 respirators. Twenty-seven evaluated UV germicidal irradiation, 19 vaporized hydrogen peroxide, 9 moist-heat incubation, 10 microwave-generated steam, and 7 ethylene oxide. Forty-three types of N95 respirators were treated with UV irradiation. Doses of 1 to 2 J/cm 2 effectively sterilized most pathogens on N95 respirators (>10 3 reduction in influenza virus [4 studies], MS2 bacteriophage [3 studies], Bacillus spores [2 studies], Escherichia virus MS2 [1 study], vesicular stomatitis virus [1 study], and Middle East respiratory syndrome virus/SARS-CoV-1 [1 study]) without degrading respirator components. Doses higher than 1.5 to 2 J/cm 2 may be needed based on 2 studies demonstrating greater than 10 3 reduction in SARS-CoV-2. Vaporized hydrogen peroxide eradicated the pathogen in all 7 efficacy studies (>10 4 reduction in SARS-CoV-2 [3 studies] and >10 6 reduction of Bacillus and Geobacillus stearothermophilus spores [4 studies]). Pressurized chamber systems with higher concentrations of hydrogen peroxide caused FFR damage (6 studies), while open-room systems did not degrade respirator components. Moist heat effectively reduced SARS-CoV-2 (2 studies), influenza virus by greater than 10 4 (2 studies), vesicular stomatitis virus (1 study), and Escherichia coli (1 study) and preserved filtration efficiency and facial fit for 11 N95 respirators using preheated containers/chambers at 60°C to 85°C (5 studies); however, diminished filtration performance was seen for the Caron incubator. Microwave-generated steam (1100-W to 1800-W devices; 40 seconds to 3 minutes) effectively reduced pathogens by greater than 10 3 (influenza virus [2 studies], MS2 bacteriophage [3 studies], and Staphylococcus aureus [1 study]) and maintained filtration performance in 10 N95 respirators; however, damage was noted in least 1 respirator type in 4 studies. In 6 studies, ethylene oxide preserved respirator components in 16 N95 respirator types but left residual carcinogenic by-product (1 study). CONCLUSIONS AND RELEVANCE Ultraviolet germicidal irradiation, vaporized h...

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Managing ICU surge during the COVID-19 crisis: rapid guidelines

et al. 2020

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Given the rapidly changing nature of COVID-19, clinicians and policy makers require urgent review and summary of the literature, and synthesis of evidence-based guidelines to inform practice. The WHO advocates for rapid reviews in these circumstances. The purpose of this rapid guideline is to provide recommendations on the organizational management of intensive care units caring for patients with COVID-19 including: planning a crisis surge response; crisis surge response strategies; triage, supporting families, and staff.

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Decontamination of N95 masks for re-use employing 7 widely available sterilization methods

Cited by 60 publications

References 32 publications

Ultraviolet-C as a Viable Reprocessing Method for Disposable Masks and Filtering Facepiece Respirators

Ultraviolet-C as a Viable Reprocessing Method for Disposable Masks and Filtering Facepiece Respirators

Filtering Facepiece Respirator (N95 Respirator) Reprocessing

Managing ICU surge during the COVID-19 crisis: rapid guidelines

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