Medical protective masks can be used for about 6~8 hours, and disposable surgical masks cannot be used for more than 4 hours. 1. Medical protective masks: medical protective masks are recommended to be replaced about every 6~8 hours, and the masks need to be replaced in time if they are contaminated. 2. Disposable medical surgical masks: disposable medical surgical masks, it is recommended that the use of time can not exceed 4 hours. Be careful not to use the mask again and again, when it is wet or contaminated by secretion, must pay attention to timely replacement. When replacing the mask, the discarded mask should be put in the yellow special garbage can, and be handled by the professional organization. To master the correct way to wear the mask, the mask edge and face close fit, so that can play a better protective effect, wearing a mask related issues suggest that you can consult the regular hospital disease prevention and control department.