Section 06 PRODUCTS OF THE CHEMICAL OR ALLIED INDUSTRIES 28 Inorganic chemicals; organic or inorganic compounds of precious metals , of rare 28 04 Hydrogen, rare gases and other non-metals. 28 04 10 28 04 10 00 Commodity Code Description 28 04 10 00 00 - Hydrogen 28 04 21 00 00 -- Argon 28 04 29 00 00 -- Other 28 04 30 00 00 - Nitrogen 28 04 40 00 00 - Oxygen 28 04 50 00 00 - Boron; tellurium 28 04 61 00 00 -- Containing by weight not less than 99.99 % of silicon 28 04 69 00 00 -- Other 28 04 70 00 00 - Phosphorus 28 04 80 00 00 - Arsenic 28 04 90 00 00 - Selenium