Respiratory protective devices are protective devices intended to protect against hazardous substances in the aeriform state such as particles, vapours and gases by means of the filtering mechanism. These devices, which partially or completely cover the face, are made of filtering material or consist of a reusable structure fitted with replaceable filters.
The EN 405 standard specifies the performance requirements, test methods and marking requirements for valved filtering half masks that incorporate gas or combined filters used as respiratory protective devices except for those intended for escape.