Filtration Performance Degradation of In-Use Masks by Vapors from Alcohol-Based Hand Sanitizers and the Mitigation Solutions

How often does one perform hand disinfection while wearing a mask? In the current COVID-19 pandemic, wearing masks and hand disinfection are widely adopted hygiene practices. However, our study indicated that exposure to the vapors from alcohol-based sanitizers during hand disinfection might degrade the filtration performance of the in-use masks, and the degradation worsened with the increasing number of hand disinfection. After five times of hand disinfection, the filtration efficiencies of surgical masks decreased by >8% for 400 and 500nm particles and by 3.68±1.83 % for 1μm particles. This was attributed to the dissipation of electrostatic charges on the masks when exposed to the alcohol vapor generated during hand disinfection. Simple practice of vapor-avoiding hand disinfection could mitigate the effects of alcohol vapor, which was demonstrated on two brands of surgical masks. The vapor-avoiding hand disinfection is recommended to be included in the hygiene guide to maintain the mask performance.