Seven days is too long to use a mask, and disinfection will destroy the protective effect of the mask. The CDC pointed out that N95 masks can be “extended use period” and “limited reuse” under strict specifications under special circumstances such as insufficient supply. 1, extended use period: refers to the user in a wear does not take down, can be appropriately extended use time; 2, limited reuse: if the manufacturer stated the number of times can be reused, the manufacturer regulations shall prevail. If no instructions, then generally no more than 5 times. Ordinary people take off and wear every day is generally far more than the number of days and times specified, and the use of alcohol disinfection may destroy the protective effect of the mask.