Section 06 Products of the chemical or allied industries 28 Inorganic chemicals; organic or inorganic compounds of precious metals, of rare - earth metals, of radioactive elements or isotopes 28 33 Sulphates; alums; peroxosulphates (persulphates) 28 33 27 Of barium 28 33 27 00 Of barium Commodity Code Description 28 33 27 00 000 Of barium