Some suggestions for odinary people to prevent themselves from Covid-19

It is enough for people to prevent 8210 in crowded places: medical mask level 3 is fine, otherwise it will be too uncomfortable. It will be useless if you don’t wear it. N95 and medical masks have a protective effect. The difference is: N95 filtering effect is 95%, ordinary medical mask filtering effect is 92%. N95 can be worn for a long time, about 8 hours must be replaced. Ordinary medical masks can only be used for 4 hours and must be changed. When you buy ordinary surgical medical masks, don’t buy that kind of gauze. They must have three layers of waterproof and one layer of cotton. I usually use N95 more often. N95 is generally used for dust prevention, that is, non-oily solid particles. If the solid particles are oily or droplets, you need to choose P95 and R95. I don’t particularly know surgeon masks. My understanding is that the role of surgeon masks and N95 are completely different. The main purpose of this mask is to prevent doctors from infecting patients, and of course he can also protect doctors. This mask is mainly to prevent liquids. For example, the patient’s blood splashed on the mask. The surgeon’s mask can protect the doctor because the liquid cannot penetrate. N95 may get soaked immediately. The purpose of ordinary people wearing masks is to prevent airborne bacteria. If an infected person spit on your face, a surgical mask is useful. However, ordinary people’s masks will not come into contact with liquid at all. So, N95 is enough. There is no need to use R95 and P95.