Masks are an important line of defense against respiratory infections and can reduce the risk of novel coronavirus infection. The mask can not only prevent the patient from spraying droplets, reduce the droplet volume and its spraying speed, but also block the virus-containing droplet core and prevent the wearer from inhaling them.

Ⅰ. Wearing principles

The basic principles are scientific and reasonable wearing, standardized use and effective protection. The details are as follows:

(1) Masks are not required in the open and ventilated place in the non-epidemic area, and masks are required when entering a crowded or closed public place.

(2) It is recommended to wear disposable surgical masks in open and ventilated places in areas with high incidence of the disease; and wear surgical masks or particulate protective masks when entering crowded or closed public places.

(3) If you come to the hospital with suspected symptoms, you should wear a particulate protective mask or a surgical protective mask without an exhalation valve.

(4) Patients with underlying respiratory diseases should use protective masks under the guidance of a doctor. And very young children or infants should not wear masks, which can cause suffocation.

(5) Cotton gauze masks, sponge masks and activated carbon masks have no protection against virus infection.

Ⅱ. Recommended mask types and user groups

(1) Disposable surgical masks: It is recommended for the public to use in non-crowded public places.

(2) Surgical masks: The protective effect is better than disposable surgical masks. It is recommended for suspected cases, drivers and passengers of the public transportation department, taxi drivers, sanitation workers, and service personnel in public places to wear while on duty.

(3) KN95 / N95 and above particulate protective masks: The protective effect is better than surgical masks and disposable surgical masks. It is recommended for field investigation, sampling and testing personnel. The public can also wear them in crowded places or closed public places.

(4) Medical protective masks: It is recommended for fever clinic, isolation ward and transfer of confirmed patients.

Ⅲ. Mask handling principles after use

(1) Masks worn by healthy people have no risk of transmission of the novel coronavirus, and they are usually replaced when the mask deforms, gets wet or dirty, resulting in decreased protective performance. The masks used by healthy people can be disposed of according to the requirements of garbage sorting.

(2) Masks worn by suspected cases or confirmed patients should not be discarded carelessly, they should be treated as medical waste, which shall be handled in strict accordance with relevant procedures of medical waste, and shall not enter the circulation market.

Ⅳ. Standards and precautions for children to wear masks

It is recommended that children choose GB2626-2006 KN95 particulate protective masks which conform to the national standard, and are labeled children or adolescents. Children should pay attention to the following when using masks:

(1) Before wearing, children need to read carefully and understand the instructions correctly with the help of parents in order to master the correct method of using respiratory protective equipment;

(2) Parents should always pay attention to the wearing of children's masks. If children feel unwell during the wearing of masks, they should adjust or stop using them;

(3) Because the face shape of children is small, it cannot fully fit with the edge of adult mask, and it is not recommended for children to wear adult mask with closeness requirements.