Section 06 PRODUCTS OF THE CHEMICAL OR ALLIED INDUSTRIES 28 Inorganic chemicals; organic or inorganic compounds of precious metals , of rare 28 11 Other inorganic acids and other inorganic oxygen compounds of non-metals. 28 11 11 Hydrogen fluoride (hydrofluoric acid) 28 11 11 00 Hydrogen fluoride (hydrofluoric acid) Commodity Code Description 28 11 11 00 00 Hydrogen fluoride (hydrofluoric acid) 28 11 12 00 00 Hydrogen cyanide (hydrocyanic acid) 28 11 19 00 00 -- Other 28 11 21 00 00 -- Carbon dioxide 28 11 22 00 00 -- Silicon dioxide 28 11 29 00 00 -- Other