Professional PM2.5 respirators are divided into two types, with and without valves, marked with N and KN. The trapping capacity of N95 for particles smaller than 2.5 microns is 95%, while that of KN90 is 90%. People with poor cardiopulmonary function are advised to choose masks with air valves as far as possible. Generally, the wearing time of this mask is about 2 days, and it is reasonable to use it repeatedly for 3-5 times, each time 1-2 hours.
Professional anti-fog PM2.5 masks are not thrown away at once, of course, they will have a certain life. According to the polluted environment and the degree of dirty and damaged masks, replace them within half a month, not too long.
Extended data:
Precautions:
1, the outer layer of the mask often accumulates a lot of dirt such as dust and bacteria in the outside air, while the inner layer will block the exhaled bacteria and saliva, so the two sides cannot be used alternately, otherwise the dirt polluted by the outer layer will be inhaled into the human body when it is directly close to the face and become the source of infection.
2. When not in use, the mask should be folded into a clean envelope, and the side close to the nose and mouth should be folded inward. Never put it in your pocket or around your neck. If the mask is wetted by exhaled hot air or saliva, its function of blocking germs will be greatly reduced.
3. For the cleaning of the mask, it is necessary to avoid the alternate use of both sides, and avoid inhaling the dirt from the outer layer into the human body when it is directly attached to the face, thus becoming a source of infection. At the same time, the masks you wear should be cleaned daily, exposed to the sun as much as possible or disinfected with purple light.
Baidu encyclopedia -PM2.5 protective mask
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