1. 1f the mask is contaminated, such as blood stains or droplets, etc.
2< 3. The mask was damaged the dust-proof filter cotton, under the condition that the mask fits well with the user’s face, when the user feels great respiratory resistance, it means that the filter cotton is covered with dust particles and should be replaced when the mask fits well with the user’s door, when the user smells poison, it’s time to replace it with a new one the outer layer of the mask often accumulates a lot of dust, bacteria and other pollutants in the outside air, while the inner layer blocks the exhaled bacteria and saliva. Therefore, the two sides can not be used alternately, otherwise the pollutants from the outer layer will be inhaled into the human body when they are directly close to the face, and become the source of infection. When the mask is not worn, it should be folded and put into a clean envelope, and the side close to the nose and mouth should be folded inward. Do not put it into the pocket or hang it around the neck if the mask is moistened by exhaled heat or saliva, its function of blocking bacteria will be greatly reduced. Therefore, it’s better to prepare more masks to replace them. They should be changed and washed once a day. When washing, blanch with boiling water for 5 minutes, then rub gently with hands, wash with clean water and expose to the sun. But there are activated carbon filtration and disposable, do not have to clean