WCO Explanatory Notes reproduced for reference. © World Customs Organization. Verify against official WCO publication.
29.10 - Epoxides, epoxyalcohols, epo henols and epoxyethers, with a three-membered ring, and their halogenated, sulp onated, nitrated or nitrosated derivatives. "R 29 10.10 - Oxirane (ethylene oxide) 2910.20 2910.30 - Methyloxirane bropylene oxide) - 1-Chloro-2,3-epoxypropane(epichlorohydrin) 2910.40 - Dieldrin (ISO,INN) 2910.90 - Other If one molecule of water is removed from organic corn ounds (diols, glycols) having two hydroxyl groups in the molecule, stable internal ethers are ormed. ? Thus ethylene glycol minus one molecule of water gives oxirane (ethylene oxide or epoxyethane) : The epoxide derived fiom propylene glycol (i.e., ethylene glycol in which one atom of hydrogen has been replaced by a methyl radical (-CH3) is known as methyloxirane (1,2-epoxypropane or propylene oxide) : The epoxide derived from ethylene glycol in which one atom of hydrogen has been replaced by a phenyl radical (-Ca5)is known as styrene oxide (a-P-epoxyethylbenzene) : This heading covers only compounds with three-membered epoxy rings, e.g. : (1) Oxirane (ethylene oxide). Colourless gas at room temperature; liquid below 12 "C. Obtained by catalytic oxidation of ethylene derived from cracking ases. An insecticide and hngicide; extensive1 used for preserving fruit and other foo stuffs. Also used in d organic synthesis, and in &e manufacture of plasticisers and surface-active products. (2) Methyloxirane (propylene oxide). Colowless liquid with an ether-like odour; used as a solvent for cellulose nitrate, cellulose acetate, gums and resins, and as an insecticide; also employed in organic synthesis (plasticisers and surface-active products, etc.). (3) Styrene oxide. This heading also includes : (A) Epo~alcohols,epoxyphenols and epoxyethers. These contain alcohol, phenol and ether functions, respecbvely, in addition to the epoxide grouping. (BI , , Haloeenated. sulnhonated. nitrated or nitrosated derivatives of euoxides. and anv comb?nations of ihese derivatives (for example, nitrosulphonated, s;lphohdogenated, nitrohalogenated and nitrosulphohalogenated derivatives). These halogenated derivatives include : 1-chloro-23-epoxypropane (epichlorohydrin), a highly volatile, unstable liquid. This heading excludes epoxides with four-membered rings (heading 29.32).
1.- Except where the context otherwise requires, the headings of this Chapter apply only to : (a) Separate chemically defined organic compounds, whether or not containing impurities; (b) Mixtures of two or more isomers of the same organic compound (whether or not containing impurities), except mixtures of acyclic hydrocarbon isomers (other than stereoisomers), whether or not saturated (Chapter 27); (c) The products of headings 29.36 to 29.39 or the sugar ethers, sugar acetals and sugar esters, and their salts, of heading 29.40, or the products of heading 29.41, whether or not chemically defined; (d) The products mentioned in (a), (b) or (c) above dissolved in water; (e) The products mentioned in (a), (b) or (c) above dissolved in other solvents provided that the solution constitutes a normal and necessary method of putting up these products adopted solely for reasons of safety or for transport and that the solvent does not render the product particularly suitable for specific use rather than for general use; (f) The products mentioned in (a), (b), (c), (d) or (e) above with an added stabiliser (including an anti- caking agent) necessary for their preservation or transport; (g) The products mentioned in (a), (b), (c), (d), (e) or (f) above with an added anti-dusting agent or a colouring or odoriferous substance or an emetic added to facilitate their identification or for safety reasons, provided that the additions do not render the product particularly suitable for specific use rather than for general use; (h) The following products, diluted to standard strengths, for the production of azo dyes : diazonium salts, couplers used for these salts and diazotisable amines and their salts. 2.- This Chapter does not cover : (a) Goods of heading 15.04 or crude glycerol of heading 15.20; (b) Ethyl alcohol (heading 22.07 or 22.08); (c) Methane or propane (heading 27.11); (d) The compounds of carbon mentioned in Note 2 to Chapter 28; (e) Immunological products of heading 30.02; (f) Urea (heading 31.02 or 31.05); (g) Colouring matter of vegetable or animal origin (heading 32.03), synthetic organic colouring matter, synthetic organic products of a kind used as fluorescent brightening agents or as luminophores (heading 32.04) or dyes or other colouring matter put up in forms or packings for retail sale (heading 32.12); (h) Enzymes (heading 35.07); (ij) Metaldehyde, hexamethylenetetramine or similar substances, put up in forms (for example, tablets, sticks or similar forms) for use as fuels, or liquid or liquefied-gas fuels in containers of a kind used for filling or refilling cigarette or similar lighters and of a capacity not exceeding 300 cm3 (heading 36.06); (k) Products put up as charges for fire-extinguishers or put up in fire-extinguishing grenades, of heading 38.13; ink removers put up in packings for retail sale, of heading 38.24; or (l) Optical elements, for example, of ethylenediamine tartrate (heading 90.01). 3.- Goods which could be included in two or more of the headings of this Chapter are to be classified in that one of those headings which occurs last in numerical order. 4.- In headings 29.04 to 29.06, 29.08 to 29.11 and 29.13 to 29.20, any reference to halogenated, sulphonated, nitrated or nitrosated derivatives includes a reference to compound derivatives, such as sulphohalogenated, nitrohalogenated, nitrosulphonated or nitrosulphohalogenated derivatives. Nitro or nitroso groups are not to be taken as “nitrogen-functions” for the purposes of heading 29.29. For the purposes of headings 29.11, 29.12, 29.14, 29.18 and 29.22, “oxygen function”, the characteristic organic oxygen-containing group of those respective headings, is restricted to the oxygen-functions referred to in headings 29.05 to 29.20.