The mask should have a high dust stopping efficiency. The efficiency of a mask is measured by its dust stopping efficiency against fine dust, especially respirable dust below 5 μm.
Place the fingertips of both hands on the nose clip, starting from the middle, press inwards with your fingers and gradually move to the sides to shape the clip to the bridge of the nose
FFP2 category masks are similar to N95 and KN95 masks in that they are not washable. Wetting will cause the mask to discharge static electricity and will not attract dusts smaller than 5um in diameter.