Gas mask filter respirator cartridge color codes: A. Organic gas and vapor with boiling point above 65°C (solvents, hydrocarbons, alcohols, benzene, ethanol, refrigerants/freons, white spirit) AX. Organic compound gas and vapor with boiling point below 65°C (many VOCs, methyl acetate, acetone, chloroform, methanol, phenol, styrene) B.