The N95 mask is one of nine standards developed by NIOSH in 1995. "N" means "not resistant to oil". "95" indicates exposure to a specified number of dedicated test particles, and the concentration of particles in the mask is 95% lower than the concentration of particles outside the mask. 95% of this value is not the average but the minimum.
Other NIOSH-certified particle barrier grades include: N99, N100, R95, R99, R100, P95, P99, P100. These protection levels cover the range of N95 protection, where “R” means oily or non-oily. Particulate matter, if used for the protection of oily particulate matter, the use time is not more than 8 hours; "P" means that it is suitable for oily or non-oily particulate matter. If used for oily particulate matter, the use time should follow the manufacturer's recommendations. And "99" and "100" refer to the level of filtration efficiency, respectively.
According to the oil resistance, it is divided into "N", "R", and "P", and is classified into "95", "99", and "100" according to the capture rate. "R" means "resistant to oil" and "P" means "oil proof", and "99" in the capture ratio means 99% or more, and "100" means 99.7% or more.
In addition, when the N100, P100, and R100 three-type masks are tested with 0.3 micron particles, the barrier efficiency must be above 99.7%, and the N99, P99, and R99 filters are all above 99%, while the N95, P95, and R95 are all filtered. More than 95%.
Therefore, the N95 mask is tested with 0.3 micron sodium chloride particles, and the barrier rate must be above 95%. When the wearer's face is tightly tested, it is ensured that air can enter and exit through the mask under the condition of the close-faced face. The N95 certification number is issued only if this test is met. In general, the protective masks that have passed the domestic standard certification are not up to the N95 standard.
