N95 mask refers to a mask that has been certified by the National Institute of Occupational Safety and Health (NIOSH) with a protective effect of not less than 95% of non-oily particles. It is also not a specific product name. The mask material is suitable for non-oily particles (such as dust, acid mist, microorganisms, etc.), with a filtering effect of 95%.
The key is:
Generally speaking, N95 masks and KN95 masks have the same protective effect. The difference is that KN meets Chinese standards and N meets American standards.
In China, KN95 means that the filtration efficiency of non-oily particles above 0.075 microns is greater than 95%. In the NIOSH standard, N95 has a 95% blocking success rate for particles with a diameter of 0.075 microns.
Since the diameter of the Coronavirus Pneumonia (SARS) virus is about 0.1 to 0.12 microns, wearing N95 or KN95 masks is a viable preventive method.
In addition, medical surgical masks can also be used to prevent infectious diseases. Medical surgical masks can block 70% of bacteria, while N95 masks can block 95% of bacteria. The latter has a strong barrier effect.
However, paper masks, activated carbon masks, cotton masks and sponge masks are not compact enough to prevent infection.