If the mask is damaged or contaminated, it should be replaced as soon as possible.
If it is not polluted, just to play a protective role in ordinary public places, not in medical places:
Disposable medical masks: “Remove contact with face, nose and nose = one more time”, discard after use;
Medical surgical masks: Replace every 2 to 4 hours. If the inside of the mask is wet or contaminated, it should be replaced as soon as possible;
KN95/Medical protective mask: Generally, when the mask is damaged, dirty or the respiratory resistance is obviously increased, a new mask needs to be replaced. If the nose clip is damaged, the headband becomes loose, the mask is deformed/odorous, etc., it needs to be replaced in time
Post time: Jul-13-2020