If pathogens are mainly spread through droplets of large particles (such as droplets produced when a patient sneezes or coughs and sticks to other people), it is more appropriate to wear a general medical surgical mask with a waterproof outer layer;
If the particles of germs or harmful substances are very small and can be suspended in the air for a long time and spread through the air, it is best to wear an industrial medical surgical mask effect. This is the lowest level protective mask for tuberculosis, SARS and other airborne diseases recognized by the CDC ；
Medical surgical masks prevent the new coronavirus
Medical/surgical medical surgical masks also meet the medical surgical standards in terms of particle filtering effect, but they can also be waterproof to prevent blood, body fluids and other liquids from splashing and permeating into the mouthpiece. The FDA approved it as a surgical mask.
For influenza virus prevention and other diseases that are mainly spread by droplets, it is more cost-effective for ordinary people to choose medical masks. The new coronavirus (2020) can also be spread through droplets and contact, similar to how influenza viruses spread.
First of all, medical surgical masks can only block 95% of particles (not 100% defense), and strict procedures must be followed to wear medical surgical masks. If used improperly, the protective effect will be greatly reduced. Research published in 2008 showed that the correct use of masks can effectively reduce the spread of influenza virus infection. However, there is no significant difference between using P2 masks without air density test (equivalent to medical surgery) and using medical surgical masks.
Data from another study showed that wearing a mask alone cannot prevent influenza (651, 240), but wearing a mask combined with frequent hand washing can reduce the incidence of influenza by 75%. Therefore, to prevent infection, the most important thing is to wash your hands frequently!