ABSTRACT
This study aims to propose decontamination methods that are suitable for use by members of the public to cope with the shortage of surgical masks during the current COVID-19 pandemic. 3-ply surgical masks were subjected to different decontamination protocols (heat, chemical, ultraviolet irradiation) to assess their abilities to achieve at least 4-log reduction of two common respiratory pathogens, H1N1 Influenza A virus, a single-stranded RNA enveloped virus similar to SARS-CoV-2 and Staphylococcus aureus, a Gram-positive bacterium that is more resistant to decontamination than single stranded RNA enveloped virus. Decontaminated surgical masks were assessed for differences in breathability, particle filtration efficiency and bacteria filtration efficiency as compared with non-decontaminated masks. The number of decontamination cycles that the 3-ply surgical masks could undergo without significant changes in breathability and filtration efficiencies were also determined. It was found that surgical masks decontaminated by either soaking for 60 min in 0.5% (v/v) aqueous hydrogen peroxide solution, or 30 min of soaking in 0.05% - 0.5% (v/v) aqueous sodium hypochlorite diluted from household bleach or ultraviolet irradiation by a surface dose of 13.5 kJ/m2 were able to achieve at least a 4-log reduction of both Staphylococcus aureus and H1N1 Influenza A virus spiked on surgical mask test swatches. No significant changes in breathability and filtration efficiencies of the surgical masks were observed after ten decontamination cycles of hydrogen peroxide or diluted bleach treatment or 30 cycles of ultraviolet irradiation.