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; polyphosphoric acids, whether or not chemically defined Commodity Code Description 28 09 10 - Diphosphorus pentaoxide 28 09 20 - Phosphoric acid and polyphosphoric acid