Science popularization of n95 mask
N95 respirator is one of the nine particulate protective masks certified by NIOSH (National Institute for Occupational Safety and Health). N95 is not a specific product name. As long as it meets the N95 standard and passes the NIOSH review, it can be called N95 respirator. It can filter particles with an aerodynamic diameter of 0.075 µ m ± 0.020 µ m with a filtration efficiency of more than 95%.
N95 respirator is one of the nine kinds of particle respirators certified by NIOSH. "N" means not resistant to oil. "95" means that when exposed to a specified number of special test particles, the particle concentration inside the mask is more than 95% lower than that outside the mask. The value of 95% 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 passes the NIOSH review, it can be called "N95 respirator". The protection grade of N95 means that under the detection conditions specified in the NIOSH standard, the filter efficiency of the mask filter material for non-oily particles (such as dust, acid mist, paint mist, microorganism, etc.) reaches 95%.
The N95 respirator has a filtration efficiency of more than 95% for particles with aerodynamic diameter of 0.3 µ m. The aerodynamic diameter of airborne bacteria and fungal spores mainly varies between 0.7-10 µ m, which is also within the protection range of N95 respirator. Therefore, N95 respirator can be used for respiratory protection of some particles, such as dust generated during grinding, cleaning and processing of minerals, flour and some other materials, and also for liquid or non-oily particles that do not produce harmful volatile gases due to spraying. It can effectively filter and purify the inhaled abnormal odor (except toxic gas), help reduce the exposure level of some inhalable microbial particles (such as mold, anthrax, tuberculosis, etc.), but it cannot eliminate the risk of contact infection, illness or death.
The United States Department of Labor has recommended that medical staff use N95 masks to prevent airborne diseases such as influenza and tuberculosis.
