A P1 filter is a type of particle filter designed for respirators and half masks. The designation „P“ means that the filter is intended for protection against solid particles and liquid aerosols, which are tiny droplets of liquids dispersed in the air. The digit „1“ indicates the lowest protection class according to the European standard EN 143. This filter must capture at least 80 % of particles present in the air. It is used in environments with low concentrations of non-toxic dust, for example during general cleaning, manual sanding, or when working with harmless materials.