FFP standards refer to the filtering half mask classification by EN 149, a European standard of testing and marking requirements for filtering half masks. FFP standard masks (where FFP stands for filtering facepiece) cover the nose, mouth and chin and may have an exhalation valve.

EN 149 defines three classes of such particle half masks, called FFP1, FFP2, and FFP3, according to their filtering efficiency. It also classifies masks into "single shift use only" (not re-usable, marked NR) or "re-usable (more than one shift)" (marked R), while an additional marking letter D indicates that a mask has passed an optional clogging test using dolomite dust. Such mechanical filter respirators protect against the inhalation of particulates such as dust particles, droplets, and aerosols.