The use of germicidal ultraviolet light, vaporized 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, ultraviolet (UV) irradiation, vaporized H 2 O 2 , and dry heat treatment. Viruses were recovered from sample materials and viral titres were measured in swine testicle cells. Findings UV irradiation, vaporized H 2 O 2 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, vaporized H 2 O 2 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 United States Food and Drug Administration policy regarding face masks and respirators. It presents advantages of uncomplicated manipulation and utilization in a BSL2 facility, therefore being easily adaptable to other respirator and mask types.

Is it Possible to Mechanical Recycle the Materials of the Disposable Filtering Masks?

“…It is therefore apparent from a medical point of view that, even if the masks were from infected subjects, the virus would no longer persist after 10 days. Any further treatment for disinfection would have to be deeply evaluated but already studied by several researchers [ 10 , 12 , 13 , 15 , 16 ].…”

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.…”

Decontamination methods for respiratory protection mask model N95: a rapid review

“…Hydrogen peroxide Hydrogen peroxide was evaluated in its liquid, plasma and gas/vapor forms by nineteen laboratory studies. 28,[35][36][37][38][39]43,47,[53][54][55][56][57]60,61,64,68,70,71 The effect of hydrogen peroxide on the ltering capacity varied according to the method used. Hydrogen peroxide plasma led to changes in the masks' metallic nasal clips 61 and degradation in their ltering performance.…”

“…The effect of ultraviolet germicidal irradiation on N95 respirators masks was evaluated by 21 studies 24,28,30,33,37,42,[45][46][47][48]50,51,53,56,[58][59][60][61][62][63]65 and there was a difference between studies in relation to UVGI doses and application of time periods. In general, UVGI did not affect the integrity and ability of the masks to lter aerosols or adapt to the face, nor did it leave a smell, irritating/toxic residues, or create important changes in appearance even when multiple cycles were performed.…”

“…The use of dry heat was evaluated for by eleven different experimental studies. 27,28,[40][41][42]47,52,[59][60][61]66 Temperatures between 70 and 85 °C did not affect the structural characteristics of the masks under various humidity conditions (≤100% RH). 28,42 The ltering e ciency remained acceptable (≥95%) up to 50 cycles at 85 °C and 30% of RH.…”