Section 06 Products of the chemical or allied 28 Inorganic chemicals; organic or inorganic compounds of precious metals, of rare earth metals, of radioactive elements or isotopes 28 09 Diphosphorus pentaoxide; phosphoric acid and polyphosphoric acids 28 09 20 Phosphoric acid and polyphosphoric acids Commodity Code Description 28 09 20 00 Phosphoric acid and polyphosphoric acids 28 09 20 31 Hypophosphoric acid 28 09 20 32 Phosphoric acid 28 09 20 39 Other 28 09 20 91 Hypophosphoric acid 28 09 20 92 Phosphoric acid 28 09 20 99 Other