N95 mask profile editor
The N95 mask is one of nine NIOSH certified particle respirators.”N” stands for not resistant to oil.”95″ means that the concentration of particles in the mask is more than 95% lower than the concentration of particles outside the mask when exposed to a specified number of specialized test particles.95% of these values are not averages, but minimums.The N95 is not a specific product name, as long as it meets the N95 standard and is approved by NIOSH.The protection grade of N95 means that the filtration efficiency of mask filter material on non-oily particulate matter (such as dust, acid mist, paint mist, microorganism, etc.) is 95% under the testing conditions stipulated by NIOSH standard.
Function and purpose editing
The filtration efficiency of N95 mask on particles with aerodynamic diameter of 0.075 m±0.02 m is more than 95%.The aerodynamic diameters of airborne bacterial and fungal spores vary mainly between 0.7 and 10 m and are also within the range of the N95 mask.Therefore, N95 mask can be used for the respiratory protection of certain particles, such as polishing, cleaning and processing of dust from mineral, flour and some other materials, etc., it is also suitable for the liquid or non-oily particles produced by spraying, which do not produce harmful volatile 
gases.It can effectively filter and purify the abnormal odors inhaled (except toxic gases), help to reduce the exposure level of some inhalable microbial particles (such as mold, anthrax bacillus, tuberculosis bacillus, etc.), but it does not eliminate the risk of contact infection, illness or death [1].
The U.S. department of labor has recommended N95 masks for health care workers to protect against airborne infections such as influenza and tuberculosis.
Safety standards editor
Other NIOSH certified respirators include N95, N99, N100, R95, R99, R100, P95, P99, and P100.These levels of protection can cover the protection range of N95.
“N” stands for not resistant to oil, suitable for non-oily particles.
“R” stands for oil resistant to oil, suitable for oily or non-oily particles. If used for protection of oily particles, the use time should not exceed 8 hours.
“P” stands for oil proof, suitable for oily or non-oily particles, if used for oily particles, the use time should follow the manufacturer’s recommendations.
“95″, ”99″ and ”100″ refer to the filtration efficiency level when tested with 0.3 micron
Suitability checking editor
In addition to the filtration efficiency of the mask, the tightness between the mask and the face is one of the important factors determining the effectiveness of the mask.Therefore, the suitability of the mask should be tested before use.When testing the tightness of the wearer’s face, ensure that air can pass in and out of the mask under the condition of close fitting to the edge of the face.
Dust and medical editor
Cao xuejun, deputy director general of the consumer goods industry department of the ministry of industry and information technology, said at a press conference on Tuesday,
N95 masks are masks with filtration efficiency up to 95% standard. They are divided into two categories: industrial dust protection and medical protection.[2]
“Workers pack medical-protective N95 masks (photo taken on Feb. 8).In recent days, shenyang shengshi medical technology co., LTD., the only manufacturer of medical-protective N95 masks in liaoning province, has been continuously producing more than 20 hours a day to ensure the daily production capacity of more than 20,000 masks for hubei province and liaoning province.[3]
Industrial dustproof N95 and KN95 are anti - non - oily particles, and medical N95 is a medical respirator (not only anti - particles, also need to prevent fluid, etc.).(the picture in the appendix of 
xinhuanet.com is ”N95″ and the following is ”medical protective mask”)