The N95 mask is actually a respirator, a respirator is a respirator that is designed to fit more tightly around the face than a regular mask and is very effective at filtering particles from the air. Among them, N stands for Not resistant to oil, which can be used to protect non-oil suspended particles; 95 means that the filtration efficiency is greater than or equal to 95%, indicating that when carefully tested, the respirator can block at least 95% of very small (0.3 micron scale) test particles.
In terms of design, if the wearer's own protection ability is ranked in order of priority (from high to low) : N95 mask > surgical mask > normal medical mask > normal cotton mask.
When worn correctly, the N95's filtration capacity is superior to that of regular masks and surgical masks. However, even if the wearer is fully compliant with the requirements, the risk of contracting disease or dying is not 100% eliminated.
KN95 is one of the grades specified in the Chinese standard GB2626-2006
N95 is one of the grades specified in American Standard 42 CFR 84.
The technical requirements and testing methods of these two levels are basically the same.
The filtration efficiency is 95% under the corresponding standard.