Decontamination and reuse of surgical masks and N95 filtering facepiece respirators during the COVID-19 pandemic: A systematic review

Abstract

Objective: Surgical masks and N95 filtering facepiece respirators (FFRs) prevent the spread of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection and protect medical personnel. Increased demands for surgical masks and N95 FFRs during the Coronavirus disease 2019 (COVID-19) pandemic has resulted in the shortage crisis. However, there is no standard protocol for safe reuse of the N95 FFRs. This systematic review aims to evaluate the effectiveness of existing decontamination methods of surgical masks and N95 FFRs and provide evidence-based recommendations for selecting an appropriate decontamination method. Methods: Systematic searches of Ovid MEDLINE and Ovid EMBASE electronic databases were performed. The date of the last search was 11 April 2020. Any trials studying surgical masks and/or N95 FFRs decontamination were included. Outcomes were disinfections of virus and bacteria, restorations of the filtration efficiency and the physical structure of the masks. Results: Fifteen studies and fourteen decontamination methods were identified. Low level of evidence supported four decontamination methods, which were ultraviolet germicidal irradiation (9 studies), moist heat (5 studies), microwave generated steam (4 studies), and hydrogen peroxide vapor (4 studies). Therefore, recommendations as an ‘option’ were given to these four methods while ‘recommendation against’ was given to the other ten methods. Conclusions: Low level of evidence supported the use of ultraviolet germicidal irradiation, moist heat, microwave generated steam, and hydrogen peroxide vapor for decontamination and reuse of N95 FFRs. These decontamination methods were effective for virus and bacterial disinfection, and restoration of the filtration efficiency and the physical structure of the FFRs.

Analysis of SteraMist ionized hydrogen peroxide technology in the sterilization of N95 respirators and other PPE

“…Use of standard bacterial indicators were chosen over tests with SARS-Cov-2 virus for three reasons. First, spores in bacterial indicators (BIs) are known to be substantially more resilient to hydroxyl radicals than enveloped viruses 6 and it is well established that H 2 O 2 is an effective a sterilant for virus similar to coronaviruses 29 . Second, the primary question being addressed with bacterial indicators in the current work is whether hydrogen peroxide vapor is sufficiently dispersed in the treatment chamber to reach all PPE regardless of variation in placement.…”

Inactivation of Human Coronavirus by FATHHOME’s Dry Sanitizer Device: Rapid and Eco-Friendly Ozone-Based Disinfection of SARS-CoV-2

“…Surgical masks and N95 FFRs prevent workplace exposure to SARS-CoV-2 in essential healthcare and non-healthcare settings [ 43 ]. Concerned by the pandemic potential of COVID-19, use of face masks, surgical masks (to filter infectious particles spreading via droplets), and N95 FFRs (to filter at least 95% of particulates), became mandatory in nearly all COVID-19 affected countries.…”

“…Although FFRs are essential to protect from airborne viruses, the use of a contaminated FFR could potentially serve to self-inoculate or spread the virus to patients or other healthcare workers. Existing decontamination strategies of PPE include ultraviolet germicidal irradiation (UVGI) [ 33 , 39 , 40 ], heat sterilization [ 41 , 42 ], chemical disinfectants [ 43 ], microwave radiation [ 40 , 41 ], and vapor phase hydrogen peroxide (VHP) [ 44 , 45 ]. While these methods can effectively reduce pathogen load, material damage such as that caused by heat sterilization, peroxide vapor treatment, microwave irradiation, and chemical disinfectants may result in poor fit, reduced filtration efficiency, and breathability, which will in turn increase the wearer’s potential exposure to pathogens [ 33 , 46 , 47 ].…”

Inactivation of Human Coronavirus by Fathhome’s Dry Sanitizer Device: Rapid and Eco-friendly Ozone-based Disinfection of SARS-CoV-2

“…Surgical masks and N95 FFRs prevent workplace exposure to SARS-CoV-2 in essential healthcare and non-healthcare settings [44]. Concerned by the pandemic potential of COVID-19, use of face masks, surgical masks (to filter infectious particles spreading via droplets), and N95 FFRs (to filter at least 95% of particulates), became mandatory in nearly all COVID-19 affected countries.…”

“…Although FFRs are essential to protect from airborne viruses, the use of a contaminated FFR could potentially serve to self-inoculate or spread the virus to patients or other healthcare workers. Existing decontamination strategies of PPEs include ultraviolet germicidal irradiation (UVGI) [33,40,41], heat sterilization [42,43], chemical disinfectants [44], microwave radiation [41,42], and vapor phase hydrogen peroxide [45,46]. While these methods can effectively reduce pathogen load, material damage such as that caused by heat sterilization, peroxide vapor treatment, microwave irradiation, and chemical disinfectants may result in poor fit, reduced filtration efficiency and breathability which will in turn increase the wearer's potential exposure to pathogens [33,47,48].…”