Vitrex 331305 a1 replacement filters are used to protect lungs against organic vapours and gases with a boiling point above 65c a1 filters offer protection when spraying timber treatments in areas of toxic dust toxic fumes and toxic mists and are suitable for most do it yourself spraying applications organic vapour examples alcohols benzene carbon tetrachloride glutaraldehyde methyl ethyl ketone mek octane phenol propanol styrene trichloroethane trichloromethane tetrachloroethylene and toluene