1. Wash your hands before wearing a mask, or avoid touching your face with the inside of the mask during wearing the mask to reduce the possibility of the mask being contaminated.

2. Distinguish the inside and outside of the mask, up and down.

3. Do not squeeze the mask with your hands. The N95 mask can only isolate the virus on the surface of the mask. If you squeeze the mask with your hands, the virus will wet the mask with the droplets, which may cause virus infection.

4. Try to make the mask fit tightly to the face. The simple test method is: after putting on the mask, exhale hard, and air cannot leak out from the edge of the mask.

5. The protective mask must be in close contact with the user’s face. The user must shave his beard to ensure that the mask can fit tightly to the face. The beard and anything placed between the mask seal and the face will leak the mask.

6. After adjusting the position of the mask according to your face shape, apply forefingers with both hands to press the nose clip along the upper edge of the mask to make it close to the face.

Masks should be replaced in time when:

1. When the respiratory impedance is significantly increased;

2. When the mask is damaged or damaged;

3. When the mask cannot be tightly attached to the face;

4. The mask is contaminated (such as when stained with foreign matter such as blood or droplets);

5. Masks have been contaminated (have been used in individual wards or contact with patients);

6. If it is a mask containing activated carbon, and there is an odor in the mask;

7. Use the mask longer than the recommended time.