Filtering facepiece respirators (FFR), sometimes known as disposable respirators or face masks, are subject to many varied regulatory standards from around the world. These standards specify certain required physical properties and performance characteristics for respirators to claim compliance with that standard.
During emergencies, health authorities have referenced these standards when making face mask recommendations, stating for example, that you should use N95 or KN95 masks.
What makes these masks different from one another? They have similar names and it can be easy to confuse the two.
There is a chart that compares these two face masks as well as others, and there are some features these masks to share.
The reason why one is named N95 and the other KN95 has to do with which countries standards they follow. N95s follow the US standards while KN95s are the Chinese standards for masks.
Similarities of N95 and KN95
- Both masks capture the same percentage of particles at 3-micron particles each.
- Both masks require to be tested for the filtration efficiently at capturing salt particles at a flow rate of 86/L.
The Difference between N95 and KN95
- To be certified as a KN95 mask, the Chinese government requires the manufacturer of the mask to run fit tests on real humans with ≤ 8% leakage.
- The N95 mask U.S.A. standard does not require a fit test by manufacturers. This does not necessarily mean that hospitals and companies do not, and many require workers to be fit tested. But those are requirements of the company, not for the certification on the mask.
- N95 masks have slightly stricter requirements for pressure drop while users are inhaling. That means they're slightly easier to breathe through than the KN
- N95s also have slightly stricter requirements for pressure drops while a wearer is exhaling as well.
Both the N95s and the KN95s are both rated to capture 95% of particles, so the differences are slight enough that they are both exceptionally effective in what they do. Both should protect equally well, with the N95's being a touch more breathable.