Masks of protection standard N95 (US standard) and KN95 (Chinese standard) are equal with the european standard FFP2. They even have a slightly higher filter effect of at least 95 percent of the non-oily particles in the air. A further distinction is made between masks with an exhalation valve and masks without an exhalation valve. Masks without a valve filter both the inhaled air and the exhaled air so that they offer protection for yourself and others. Masks with valves only filter the inhaled air and are therefore not designed for external protection. Therefor it only protects the user and not others.
Author: Nusha Chenari.