The protection must bear the “CE” logo and refer to the EN standard. Respiratory protection can be provided in the form of a half-mask or a full mask. In the case of a half-mask, protective goggles must also be worn to prevent splashing of the eyes. The half-mask is designed to protect the respiratory tract against harmful gases and particles. Combination filters protect against particles, gases and vapors. They consist of two superimposed filters: a particulate filter (P) and an anti-gas filter (A).