The use of germicidal ultraviolet light, vaporised hydrogen peroxide and dry heat to decontaminate face masks and filtering respirators contaminated with a SARS-CoV-2 surrogate virus

Abstract

Background: In the context of the ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, the supply of personal protective equipment remains under severe strain. To address this issue, re-use of surgical face masks and filtering facepiece respirators has been recommended; prior decontamination is paramount to their re-use. Aim: We aim to provide information on the effects of three decontamination procedures on porcine respiratory coronavirus (PRCV)-contaminated masks and respirators, presenting a stable model for infectious coronavirus decontamination of these typically single-use-only products. Methods: Surgical masks and filtering facepiece respirator coupons and straps were inoculated with infectious PRCV and submitted to three decontamination treatments, UV irradiation, H2O2 vaporisation, and dry heat treatment. Viruses were recovered from sample materials and viral titres were measured in swine testicle cells. Findings: UV irradiation, H2O2 vaporisation and dry heat reduced infectious PRCV by more than three orders of magnitude on mask and respirator coupons and rendered it undetectable in all decontamination assays. Conclusion: This is the first description of stable disinfection of face masks and filtering facepiece respirators contaminated with an infectious SARS-CoV-2 surrogate using UV irradiation, H2O2 vaporisation and dry heat treatment. The three methods permit demonstration of a loss of infectivity by more than three orders of magnitude of an infectious coronavirus in line with the FDA policy regarding face masks and respirators. It presents advantages of uncomplicated manipulation and utilisation in a BSL2 facility, therefore being easily adaptable to other respirator and mask types.

Community Knowledge About the Use, Reuse, Disinfection and Disposal of Masks and Filtering Facepiece Respirators: Results of a Study Conducted in a Dermatology Clinic at the University of Naples in Italy

“…In the context of the COVID-19 pandemic period, different measures have been applied in order to reduce as much as possible the spread of infection, with the use of masks as one of the most important indication given to the population. However, the supply of personal protective equipment (PPE) represented an important problem for both availability and affordability [1]. In Italy, as well as in almost all countries, the use of masks in public with several other measures (i.e.…”

“…The correct use of masks is essential, as a wrong use and disposal may increase the rate of contagious [5]. Moreover, due to availability and affordability concerns, re-use of surgical masks and FFP has been suggested, however, a decontamination is mandatory to their re-use [1]. We developed a questionnaire called MaSK (Mask uSe and Knowledge) questionnaire to investigate the knowledge of patients about the correct use, re-use and disposal of masks and FFP used to prevent COVID-19 spread.…”

The use of germicidal ultraviolet light, vaporised hydrogen peroxide and dry heat to decontaminate face masks and filtering respirators contaminated with an infectious norovirus

“…Per decontamination method and mask type, one negative control mask or FFR (uncontaminated but treated), three treated masks or FFRs (MuNoV-contaminated and treated), and three positive controls (MuNoV-contaminated but untreated) were utilised. The workflow followed previously described protocols for mask and FFR inoculation, decontamination and virus elution [ 7 ].…”

“…We previously demonstrated efficient decontamination of masks and FFRs contaminated with an infectious SARS-CoV-2 surrogate virus via ultraviolet germicidal irradiation, vaporised hydrogen peroxide, and use of dry heat [ 7 ]. In the present investigation into decontamination of MuNoV-inoculated masks and FFRs, we show that these same methods efficiently inactivate a more resistant, non-enveloped oral virus.…”

From “don, doff, and discard” to “don, doff, and decontaminate” – determination of filtering facepiece respirator and surgical mask integrity and inactivation of a SARS-CoV-2 surrogate and a small non-enveloped virus following multiple-cycles of vaporised hydrogen peroxide, ultraviolet germicidal irradiation, and dry heat decontamination

“…We previously demonstrated efficient single-cycle VHP, UVGI, and DH decontamination of SMs and FFRs inoculated with two in vitro cultivable BSL2 pathogens. Inactivation of the infectious SARS-CoV-2 surrogate porcine respiratory coronavirus (PRCV) (26–30) demonstrated virucidal activity of all three methods against enveloped coronaviruses (31); decontamination of hardier non-enveloped human respiratory or oral pathogens, which can equally contaminate SMs or FFRs (9,32), was investigated using the notoriously tenacious murine norovirus model (MuNoV) (33–36).…”