Section 06 Products of the chemical or allied industries 29 Organic chemicals 29 18 Carboxylic acids with additional oxygen function and their anhydrides, halides, peroxides and peroxyacids; their halogenated, sulphonated, nitrated or nitrosated derivatives. 29 18 22 O-acetylsalicylic acid, its salts and esters Commodity Code Description 29 18 22 00 O-acetylsalicylic acid, its salts and esters