FFP3 masks can protect against various toxins (such as asbestos, bacteria, viruses) and are usually used by healthcare professionals when handling dangerous pharmaceutical chemicals.
The effectiveness of KN95 masks is the same as that of N95, and it is one of the "appropriate substitutes".
The filtration efficiency is 95% or above, which can prevent or reduce the dust, pollen and germs in the air from entering the human respiratory organs, such as anti-smog and anti-PM2.5.