3M 9022 masks can prevent novel coronavirus infections to some extent, as wearing a mask is an effective means of blocking the spread of respiratory secretions. If conditions allow, it is recommended to try to use medical masks that meet the standard, and special masks are recommended for heavy infection areas. 3M 9022 type masks meet China’s KN90 level filtration standards and are folded dust masks, with better contact with the face, less breathing resistance and more comfortable to wear, mainly for protection against non-oil particles such as dust, pollen and haze. However, these masks do not have good splash-proof ability and are generally waterproof, and can only be used as a temporary alternative, and the one-time use time is generally not more than 4 hours.