Section 06 PRODUCTS OF THE CHEMICAL OR ALLIED INDUSTRIES 28 INORGANIC CHEMICALS; ORGANIC OR INORGANIC COMPOUNDS OF PRECIOUS METAL, OFRARE-EARTH METALS, OF RADIOACTIVE ELEMENTS OR OF ISOTOPES 28 04 HYDROGEN, RARE GASES AND OTHER NON-METALS. Commodity Code Description 28 04 10 HYDROGEN 28 04 21 ARGON 28 04 29 OTHER RARE GASES 28 04 30 NITROGEN 28 04 40 OXYGEN 28 04 50 BORON; TELLURIUM 28 04 61 SILICON, CONTAINING BY WEIGHT NOT LESS THAN 99.99% OF SILICON 28 04 69 OTHER SILICON 28 04 70 PHOSPHORUS 28 04 80 ARSENIC 28 04 90 SELENIUM