How to choose n95 mask

N95 respirator is one of nine kinds of particle respirators certified by NIOSH (National Institute of occupational safety and health). "N" means not resistant to oil. "95" means the particle concentration in the mask is more than 95% lower than that outside the mask when exposed to a specified number of special test particles. 95% is not the average, but the minimum. The degree of protection is N95, which means that under the test conditions specified in NIOSH standard, the filtering efficiency of the filter material of the mask for non oily particles (such as dust, acid mist, paint mist, microorganism, etc.) reaches 95%. N95 is not a specific product name. As long as the product meets N95 standard and passes NIOSH review, it can be called "N95 mask". N90 type respirator has a filtering efficiency of 90%.
Use range of N95 mask:
Protection of medical staff and relevant staff against airborne respiratory infectious diseases.
Basic protection for medical personnel or related personnel, as well as protection against the spread of blood, body fluids and splashes during invasive operations.
One time health care in general environment, or barrier or protection of particles other than pathogenic microorganisms, such as flower powder, etc.
Other

NIOSH certified particle mask grades include: N95, n99, N100, R95, R99, R100, p95, p99, P100, a total of 9. These protection levels can cover the protection range of N95.
"N" means not resistant to oil, which is suitable for non oil particles and has no limit on service time.
Medical surgical mask is the mask worn by medical staff when they work. It is mainly used in medical outpatient, laboratory, operating room and other high demand medical environment, with relatively high safety coefficient and strong resistance to bacteria and viruses. Medical surgical masks can also be used to prevent the spread of influenza and respiratory diseases. There are three layers of medical surgical mask, from the outside to the inside are waterproof layer, filter layer, comfortable layer, comfortable layer is a layer of gauze.

Summary and comparison:
In terms of protection ability: N95 mask > medical surgical mask > General mask
In terms of wearing comfort: General mask ≈ medical surgical mask > N95 mask