There are four levels of mask protection. Generally, the protection level of masks is divided into four levels: A, B, C and D, and the corresponding protection effect of each level is not less than 90%, 85%, 75% and 65% respectively. The applicable polluted environment at all levels is serious pollution, serious and below pollution, serious and below pollution and moderate and below pollution.

The new standard divides the mask protection level from low to high into four levels: D, C, B and A. For example, Grade A corresponds to "serious pollution" and is used when the concentration of PM2.5 is less than or equal to 500 μ g/m3. Grade B corresponds to serious and below pollution, and is used when the concentration of PM2.5 is less than or equal to 350 μ g/m3. Consumers can choose different grades of masks according to different air quality. Third, choose masks of large, medium and small sizes according to your face. In addition, in order to meet the protection needs of people who still need to go out in the case of serious air pollution, a special protection level has been set.

legal ground

According to the classification of mask protection level, mask protection level is divided into four levels: D, C, B and A from low to high. For example, Grade A corresponds to "serious pollution" and is used when the concentration of PM2.5 is less than or equal to 500 μ g/m3. Grade B corresponds to serious and below pollution, and is used when the concentration of PM2.5 is less than or equal to 350 μ g/m3. Consumers can choose different grades of masks according to different air quality. Third, choose masks of large, medium and small sizes according to your face. In addition, in order to meet the protection needs of people who still need to go out in the case of serious air pollution, a special protection level has been set.