The N95 respirator has a filtration efficiency of more than 95% for particles with an aerodynamic diameter of 0.075µm ± 0.02µm. The aerodynamic diameter of airborne bacteria and fungal spores mainly varies between 0.7-10µm, which is also within the protection range of N95 respirator.(China N95 respi......

Because medical masks generally need to be sterile, ethylene oxide sterilization is required in order to achieve sterility standards.

China was the first in the world to use masks. In ancient times, people in the court began to cover their mouths and noses with silk scarves in order to prevent dust and breath pollution.