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. 28 45 10 Heavy water (deuterium oxide) 28 45 10 00 Heavy water (deuterium oxide) Commodity Code Description 28 45 10 00 000 Heavy water (deuterium oxide)