N95 is the certification level of American respirators, certified by the National Institute of Occupational Safety and Health. This type of mask can filter out more than 95% of non-oily particles (aerosol) under the specified air flow (85L/min), so it is named N95. And if it can filter more than 99% of particulate matter (aerosol), it is called N99 mask. In addition, corresponding to N95, KN95 is a respirator certified by my country's GB2626-2006 self-priming filter particulate respirator standard for respiratory protection products.
The protection levels of KN95 and N95 masks are equivalent, but they follow the testing standards of different countries. The KN95 mask follows the Chinese standard, and the N95 mask follows the American standard. Both of them have a protection efficiency of not less than 95% for non-oily particles (sodium chloride particles for experimental use).
Can KN95 masks be used for first-line protection?
Both KN95 masks and N95 masks include medical and non-medical types. Among them, the KN95/N95 masks with the "medical" mark can be used for the first-line protection of medical staff during the anti-epidemic period. Masks without the "medical" mark are not recommended for medical staff and ordinary people can use it. Respirators that conform to GB19083 and above level 1 can not only achieve 95% filterability, but also prevent liquid penetration, and can be used for various operations in medical institutions.
Why can KN95/N95 masks prevent viruses?
Viruses usually do not exist alone in the air, but are attached to particles such as droplets, dust, dander, etc. The filtration mechanism of KN95 and N95 masks is to block these fine particles through the high-performance filter layer in the mask, and build a Protective barrier.
Therefore, when wearing KN95/N95, that is, self-priming filter type anti-particulate respirator masks for respiratory protective equipment, pay attention to the tightness, and should be close to the face, and never leave a "convenience door" for viruses and bacteria. There are "exhalation valve" masks.