Section 06 PRODUCTS OF THE CHEMICAL OR ALLIED INDUSTRIES 28 Inorganic chemicals; organic or inorganic compounds of precious metals , of rare 28 33 Sulphates; alums; peroxosulphates (persulphates). 28 33 11 28 33 11 00 Commodity Code Description 28 33 11 00 00 -- Disodium sulphate 28 33 19 00 00 -- Other 28 33 21 00 00 -- Of magnesium 28 33 22 00 00 -- Of aluminium 28 33 24 00 00 -- Of nickel 28 33 25 00 00 -- Of copper 28 33 27 00 00 -- Of barium 28 33 29 00 00 -- Other 28 33 30 00 00 - Alums 28 33 40 00 00 - Peroxosulphates (persulphates)