At present, the masks you can see on the market are mainly: the highest protective level medical protective masks (such as N95), medical surgical masks commonly used in invasive operating environments such as operating rooms, and ordinary level disposable medical masks. In addition, there are "net red masks" such as cotton masks and sponge masks worn by various stars.

Ordinary cotton masks: they cannot prevent disease transmission.

Its material may be cotton, gauze, wool, canvas and velvet, etc. Because the material itself is not dense enough, it can only be dustproof and warm.

Medical surgical mask: it has a protective effect against viruses and bacteria.

When wearing, the white non-woven fabric is facing inwards, the blue waterproof layer is facing outwards, and the side with the metal sheet is facing up. Don't wear it on the back. So that there is no gap between the mask and the face. When purchasing, please note that you should choose a mask that clearly states "Medical Surgical Mask" on the outer packaging.

N95 mask: can effectively prevent respiratory infections.

N95 mask is one of 9 anti-particulate masks certified by NIOSH (National Institute of Occupational Safety and Health). It can effectively prevent pathogens and pathogenic particles in the air from entering the respiratory tract and nasal cavity.

N95 is not a specific product name. As long as it conforms to the N95 standard and has passed the NIOSH review, the product can be called "N95 mask".

In general, from the perspective of protective effects, N95 masks> medical surgical masks> ordinary cotton masks.

For the prevention of new coronaviruses, Zhong Nanshan, the head of the high-level expert group of the National Health and Health Commission, said that it is not necessary to wear N95, because these viruses are not actually alone. Masks and so on can still block most of the virus with droplets from entering the respiratory tract. If you are going to a general open-air public place and are not in contact with the patient, you can choose to wear a medical surgical mask without excessive protection, but if you will contact patients with suspected respiratory infections, you should wear a N95 mask.