N95, KN95, FFP2, KF94, what is the difference between these masks?

The N series of masks is the American standard, the KN series is the Chinese standard, the FFP series is the European standard, and the KF series is the Korean standard.

The number behind refers to the protection ability, the larger the protection level, the higher the protection level.

When the water molecule exists as a gas, the diameter is about 0.4nm, and the overall particle diameter of the coronavirus is about 60-400nm.

The shield cannot pass larger diameter particles, so it can block the virus.95 refers to 95% effective filtration of this type of particulate matter.

The 90 series is not as high in protection as the 95, but is also resistant to over 90% of particulate matter.

In the FFP series, 2 basically corresponds to 95, and 3 has a higher filtering efficiency, reaching 99%.