GOST 12.4.294-2015, TR CU 019/2011(EN 149:2001+A1:2009) Respiratory protection - filtering half masks for protection against aerosols and particulates. All WALL respirators are tested and approved in accordance with GOST 12.4.294-2015 (EN 149:2001+A1:2009). This standard specifies a wide range of requirements for respirators in order to provide the maximum level of protection and comfort to the user. Key tests in GOST 12.4.294-2015 (EN 149:2001+A1:2009) â?¢ measurement of inhalation and exhalation resistance â?¢ checking the exhalation valve â?¢ visual inspection (labeling, instructions for use) â?¢ determination of filtration efficiency (protection class) â?¢ testing on dolomite dust FFP 1 FFP1 respirators have a filtering capacity of at least 80% and are designed for individual protection of the human respiratory system from all types of aerosols (dust, smoke, fog) at a concentration of up to 4 maximum permissible concentrations. Such respirators are suitable for particles that are not toxic. FFP 2 FFP2 respirators have a filtering capacity of at least 94% and are designed for individual protection of the human respiratory system from all types of aerosols (dust, smoke, fog) at a concentration of up to 12 maximum permissible concentrations. Effective when working in difficult conditions, when working in areas of high and low temperatures, high humidity. FFP 3 FFP3 respirators have a filtering capacity of at least 99% and are designed for individual protection of the human respiratory system from all types of aerosols, including radioactive and carcinogenic, at a permissible concentrations of up to 50. Effective when working in difficult conditions, when working in areas of high and low temperatures, high humidity. All respirators meet the additional requirements of the dolomite dust test and are therefore marked with the letter D. Consequently, respiratory protection products provide excellent breathability even in very dusty environments and during prolonged use