Why is the mask called N95?

The N95 mask is one of nine types of particulate protective masks certified by NIOSH (National Institute for Occupational Safety and Health). "N" means not resistant to oil. "95" means that when exposed to a specified number of special test particles, the particle concentration in the mask is more than 95% lower than the particle concentration outside the mask. The 95% value is not the average value, but the minimum value. N95 is not a specific product name, as long as it meets the N95 standard, and products that pass NIOSH's review can be called "N95 masks." The protection grade of N95 means that under the test conditions specified by the NIOSH standard, the filtering efficiency of the mask filter material to non-oily particulate matter (such as dust, acid mist, paint mist, microorganisms, etc.) reaches 95%.

Function and purpose

The filtering efficiency of the N95 mask for particles with an aerodynamic diameter ≥0.3µm is above 95%. The aerodynamic diameter of air bacteria and fungal spores mainly varies between 0.7-10µm, which is also within the protection range of N95 masks. Therefore, the N95 mask can be used for respiratory protection of certain particles, such as dust generated by grinding, cleaning and handling minerals, flour and some other materials. It is also suitable for liquid or non-oily generated by spraying. It can effectively filter and purify the inhaled abnormal odors (except toxic gases), help reduce the exposure level of some inhalable microbial particulates (such as mold, anthrax, tuberculosis, etc.), but it does not eliminate the risk of contact infection, disease or death. It can also be used to wear on the mouth and nose of the medical staff in the operating room to prevent the spread of scurf and respiratory tract microorganisms to the open surgical wounds, and prevent the spread of the body fluids of the surgical patients to the medical staff, playing a two-way biological protection role.