When you search for the N95 respirators, there are many respirators such as KN95, FFP2, and KF94 that appeared in the same breath. What's different between these respirators of different letters?
Actually, both the N95, KN95, FFP2 and KF94 respirators have almost the same filtration efficiency, it means that KN95, FFP2, and KF94 are as effective as the N95 respirator mask. The main difference between these respirators is that they are tested by different nations.
The N95 mask has a full name of NIOSH-certified N95 respirator, which means these respirators are tested of 95% filtration and certified by the U.S. National Institute of Occupational Safety and Health (NIOSH). The KN95 respirator is a particulate-filtering mask tested using the China criteria. The FFP2 is a filtering facepiece score of 94% filter capacity approved by Europe, and the KF94 is tested by Korea criteria.
To simply put, we could put these respirators into an equation as below:
N100 (99.97%) = FFP3 (99.95%) > N95 (95%) = KN95 (95%) = FFP2 (94%) = KF94 (94%) > KN90 (90%).