Their protective function is verified by the Europe-wide EN 149
standard and divided into FFP2 and FFP3, these standards verify
protection from avian flu, SRAS, tuberculosis, as well as infection
respiratory pathogens, and bacteria. The two classifications also
signify the number of particulates filtered out by the mask, the FFP2
filters 94% and FFP3 filters 99%. The more particles that need to be
filtered, the greater the number of filter material layers.
Consequently, masks in the higher protection classes are thicker,
meaning breathing resistance is higher.