Heat inactivating and reusing of virus-contaminated disposable medical mask

As the prevalence of COVID-19 in all the area of China and continuous spread to many other countries, it is in urgent need of medical mask for community people. We have reported a simple method to inactivate artificially influenza virus-contaminated medical mask without affecting the filterability of mask by heating with hair dryer for 30min. In this study, we extended our studies to optimize our protocols and evaluate the filterability of mask after several-rounds of heat treatment. We found that baking at 70°C for 30min almost completely inactivated virus as hair dryer treatment for 30min described before. One-round of heat treatment with hair dryer for 30min or baking at 70°C for 30min did not affect filterability of mask whilst two-rounds of treatment slightly but significantly reduced filterability of mask. Thus, heating with hair dryer for 30min or baking at 70°C for 30min can inactive contaminated medical mask and the treated mask can be reused at least once.