Abstract:

In view of the shortage and reuse of masks caused by the COVID-19 outbreak which transmitted via droplet aerosols, based on the self-built simulation test system for individual anti-virus masks, and by replacing virus with 0-200 nm NaCl aerosols, the changes of penetration, inhalation resistance and quality factor of five masks commonly used during the epidemic were tested for 8 hours. Furthermore, five disinfection methods of hot water immersion, alcohol spraying, high-pressure steam, ultraviolet radiation and dry heating were used to treat the above five masks after 8 h testing at 85 L/min, and the penetration, inhalation resistance and quality factor of each mask before and after disinfection treatment were compared. The research results show that as the test time increases within 8 hours, the penetration of each mask increases linearly and the inhalation resistance increases slowly. After 8 h testing, the filtration efficiencies of all N95 respirators are still higher than 95%, and the inhalation resistances are far below 300 Pa, indicating that the N95 respirators can be reused. Hot water immersion, alcohol spraying and high-pressure steam disinfection treatment will cause the filtration efficiency of masks to decrease significantly, and the protective performance of the masks before disinfection cannot be maintained. Ultraviolet radiation and dry heating have no significant influence on the filtration efficiency and inhalation resistance of each mask, and thus can be used as disinfection means before the masks reusage.

Key words: disposable masks, disinfection, reuse, filtration efficiency, inhalation resistance