Filter for protection against gases and fumes with optimized adsorption. Gas filter SR 297, Class 1, is designed for use together with Sundström half masks and full face masks. The filter is of type ABEK and provides protection against the following types of gases and vapours: Type A protects against organic gases and vapours, such as solvents, with boiling points > +65 °C. Type B protects against inorganic gases and vapours, such as chlorine, hydrogen sulphide and hydrogen cyanide. Type E protects against acidic gases and vapours, such as sulphur dioxide and hydrogen fluoride. Type K protects against ammonia and certain amines, such as ethylene diamine. The gas filter can easily be combined with particle filter SR 510 P3 R in order to obtain protection also against aerosols (particles), e.g. during spray painting.