Why are there three layers of masks? Are they all of the same use?

     Mask has become an indispensable material in our life. Mask can be used in many ways in life, can isolate germs, prevent smog inhalation, keep warm, maintain a sense of mystery and so on. There is not much difference in appearance between the commonly used masks. In fact, the types of masks are also subdivided.

    Dust masks sold on the market are mostly three layers, among which the layer is commonly known as the protective layer, which has a filtering effect. However, the filtering rate of dust masks cannot meet the anti-virus standard, so it is usually not recommended to use dust masks to prevent viruses, because it does not have such a role. The most important difference between a surgical mask and a surgical mask is that it is composed of three layers, but the filter layer in the middle can filter more than 95%, effectively preventing the transmission of blood, body fluids and splashes and preventing the spread of viruses.

       3 layer non-woven masks are not as effective as medical surgical masks because the medical surgical masks have a layer of meltblown cloth in the middle to protect against viruses. These three-layer non-woven masks can be used in low-risk areas, such as open Spaces, where there are few people, but they are less effective in hospitals.  

    Medical Mask: Usually made of nonwoven material, it includes filter layer, mask strap and nose clip. A standard surgical mask has three layers. The outer layer is water-resistant to prevent droplets from entering the mask. The middle layer has filtration effect, which can block 90% of > 5μm particles. The inner layer near the nose and mouth is used for moisture absorption. In daily life, it can be used to prevent the spread of infectious diseases such as influenza and respiratory system. (1) General population: It is recommended that the general public, passengers of the Public Transport Department, taxi drivers, sanitation workers, public service personnel, etc. wear masks while on duty. Medical surgical masks are recommended, and medical protective masks can be worn when conditions permit and health conditions permit. (2) Special groups: high-risk groups who may be in contact with suspected or confirmed cases are recommended to wear medical protective masks (grade N95 or above) and goggles in principle. Patients with some cardiopulmonary diseases should consult with a professional physician before wearing, and choose an appropriate mask under the guidance of a professional physician.