Sulphates; alums; peroxosulphates (persulphates)

283311 Sodium sulphates; disodium sulphate 283319 Sodium sulphates; other than disodium sulphate 283321 Sulphates; of magnesium 283322 Sulphates; of aluminium 283324 Sulphates; of nickel 283325 Sulphates; of copper 283327 Sulphates; of barium 283329 Sulphates; n.e.c. in item no. 2833.2 283330 Alums 283340 Peroxosulphates (persulphates)