What are the precautions for masks？

Use time
From the perspective of human physiological structure, because the blood circulation of the nasal mucosa is very strong, the passage in the nasal cavity is very tortuous, and the nasal hair constitutes a filtering "barrier". When air is sucked into the nostril, the airflow forms a vortex in the tortuous passage, which warms the airflow sucked into the nasal cavity. Some tests have shown that when cold air at minus 7°C is sucked into the lungs through the nasal cavity, the airflow has been heated to 28.8°C, which is very close to the temperature of the human body. If you wear a mask for a long time, the nasal mucosa will become fragile and lose the original physiological function of the nasal cavity, so you cannot wear a mask for a long time. Masks can only be worn in special environments, such as places with a lot of people and poor air circulation. Of course, walking in the wild, in order to resist wind and sand and cold, or activities in an environment with air pollution, you need to wear a mask, but the time should not be too long. In addition, during the flu season, you should wear a mask when you go to public places where there may be a large number of pathogens. Wearing a mask is just one of the ways to prevent respiratory infectious diseases, and the most important thing is to maintain good living habits.

Cleaning and maintenance
The outer layer of the mask often accumulates a lot of dust, bacteria and other dirt in the outside air, while the inner layer blocks the exhaled bacteria and saliva. Therefore, the two sides cannot be used alternately, otherwise the dirt on the outer layer will be directly attached to it. It becomes a source of infection when it is inhaled into the human body when it is in the face. When you are not wearing the mask, you should fold it and put it in a clean envelope, and fold the side close to your nose and mouth. Don't just stuff it in your pocket or hang it around your neck.
If the mask is wetted by exhaled heat or saliva, its function of blocking germs will be greatly reduced. Therefore, it is best to prepare a few more masks so that they can be replaced. They should be changed and washed once a day. When washing, it should be scalded with boiling water for 5 minutes.
Masks should be cleaned and disinfected every day. Both gauze masks and air filter masks can be disinfected by heating. The specific approach is:
1. Cleaning. First rub the gauze mask gently with warm water and soap. The bowl-shaped mask can be gently cleaned with a soft brush dipped in detergent, and then rinsed with clean water. Please be careful not to rub it hard, because if the warp and weft gap of the gauze is too large, it will lose its anti-dropping effect.
2. Disinfection. Soak the cleaned mask in a 2% peracetic acid solution for 30 minutes or boil it in boiling water for 20 minutes or steam it in a steamer for 15 minutes, and then dry it for later use. This method is suitable for gauze masks and bowl-shaped masks.
3. Check. Before using again, you should carefully check whether the masks and face shields are still intact. For gauze masks and face shields, you can take the light transmission inspection method, that is, take the light in front of the lamp to see if there are obvious light spots. The middle part and the edge part are transparent. Is the rate consistent? If in doubt, replace it with a new one. In any case, masks and masks are generally updated after cleaning 3 to 7 times, and masks of particularly good quality can be cleaned 10 times. Activated carbon adsorption masks should pay attention to regular replacement of the activated carbon interlayer. If the activated carbon interlayer is not replaceable, it must be replaced after 7 to 14 days. This type of mask cannot be reused after cleaning.