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 45 Isotopes other than those of heading 28.44; compounds, inorganic or organic, of such isotopes, whether or not chemically defined. Commodity Code Description 28 45 10 Heavy water (deuterium oxide) 28 45 20 Boron enriched in boron-10 and its compounds 28 45 30 Lithium enriched in lithium-6 and its compounds 28 45 40 Helium-3 28 45 90 Other