How long can KN95 mask be used?

Coronavirus spreads from person to person, usually because people come into contact with the secretions of an infected person. Wearing a mask will prevent you from directly inhaling the virus in the droplets even if you come into contact with an infected person. Among them, the KN95 mask has the best defense effect. How long can the KN95 mask be used?

Some researchers have done related research on the protection efficiency and wearing time of KN95 medical protective masks. The results show that the filtration efficiency of KN95 masks remains above 95% after wearing for 2 days, and the respiratory resistance does not change much; the filtration efficiency decreases to 94.7% after wearing for 3 days. As the wearing time becomes longer, the effective isolation rate will be lower and lower, especially after three days, the isolation rate will show a landslide reduction, so it is recommended that the mask should not be worn after three days of use.

In case of the following situations, the mask should also be replaced in time:

1. When the respiratory impedance increases significantly;

2. When the mask is broken or damaged;

3. When the mask can't fit the face tightly;

4. The mask is contaminated (such as blood stains or droplets);

5. It has been used in individual wards or in contact with patients (because the mask has been contaminated).