There are three common types of : medical masks , living charcoal masks and N95 masks, which are used to block harmful gas , odor and droplets from entering and leaving the wearer's mouth and nose, which are made of gauze or paper.

1. Medical mask

Generally sold in pharmacies, there are two kinds: non woven disposable medical masks, and gauze masks, which are generally about 3 yuan / piece. People who are more sensitive to climate change can choose to wear disposable medical surgical masks or more than 12 layers of gauze masks.

It should be noted that the sterilization grade and ordinary grade marked on the outer package of medical nursing mask refer to the cleanliness of the mask itself, which has nothing to do with the filtering effect. When choosing, the public can recognize the "drug supervision and equipment approval".

2. Activated carbon mask

Pharmacies, convenience stores and online stores all sell such masks. According to the quality of the activated carbon in the masks, the price ranges from 20 to 60 yuan / bag, 50 pieces in a pack. Can also be sold individually, but generally due to the rapid replacement, so now most people are buying a whole package.

3. N95 mask

N95 mask is a professional dust mask. General pharmacies will not sell N95 and N90 masks, and hospitals will not sell them to the public, let alone ordinary patients. People need to go to pharmaceutical companies to buy them.

Experts suggest that ordinary citizens should not wear professional protective masks blindly. Wearing such professional protective masks should be trained. If they do not understand this knowledge, it is better not to wear them at will.