This European Standard specifies performance requirements, test methods and marking requirements for half masks (re-usable) without inhalation valves and with separable filters (designed for a maximum of single shift use) to protect against gases or gases and particles or particles only. It does not cover devices designed for use in circumstances where there is or might be an oxygen deficiency (oxygen less than 17 % by volume) or for escape purposes. Laboratory and practical performance tests are included for the assessment of compliance with the requirements.