WCO Explanatory Notes reproduced for reference. © World Customs Organization. Verify against official WCO publication.
29.20 - Esters of other inorganic acids of non-metals (excluding esters of hydrogen halides) and their salts; their halogenated, sulphonated, nitrated or nitrosated derivatives. - Thiophosphoric esters (phosphorothioates) and their salts; their halogenated, sulphonated, nitrated or nitrosated derivatives : 2920.1 1 - - Parathion (ISO) and parathion-methyl (ISO) (methyl-parathion) 2920.19 -- 2920.90 - Other Other This heading covers esters of other inorganic acids of nonmetals, that is, acids in which the anion contains onIy non-metal elements. This heading does not cover : (a) "Esters" of the hydrogen halides (generally heading 29.03), and (b) Esters included in later headings of this Chapter (e.g., "esters" of isocyanic acid (isocyanates) (heading 29.29) and "esters" of hydrogen sulphide (generally heading 29.30). The esters of this heading include : (A) Thiophosphoric esters hosphorothioates) and their 0,O-dibutyl- and 0,O-ditoly dithiophosphates. 'p salts, including sodium (B) Sulphuric esters and their salts. Sulphuric esters may be either neutral or acid. (1) Methyl hydrogen sulphate (CH30S020H).An oily liquid. (2) Dimethyl sulphate ((CH30)2S02. Colourless or slightly yellow liquid with a slight odour of mint; toxic, corrosive, achrymatory and irritating to the respiratory tracts. Used in organic synthesis. (3) Ethyl hydrogen sulphate (C2H50S020H).Syrupy liquid. (4) Diethyl sulphate ((C2H50)2S02). Liquid with an odour of mint, (C) Nitrous and nitric esters. Nitrous esters are liquids with an aromatic odour, e.g., methyl, ethyl, propyl, butyl and pentyl nitrites. Nitric esters are mobile li uids with an agreeable odour; they decompose when suddenly heated. They include methy ,ethyl, propyl, butyl and pentyl nitrates. 'I Nitroglycerol, tekanitropentae thritol {penthrite) and nitroglycol are classified here if unmixed; when presented in %e form of prepared explosives they are excluded (heading 36.02). (D) Carbonic or peroxocal-bonic esters and their salts. Esters of carbonic acid may be acid or neutral. (I) Diguaiacyl carbonate. Crystalline light white powder, with a slight odour of guaiacol. Used in medicine and as an intermediate in synthesis of perfumes. (2) Tetraethyl orthocarbonate (C(OC2H,)4). (3) Diethyl carbonate (C(OC2H5)2). (4) Bis(4-tert-butylcyclohexyl) peroxodicarbonate. Ethyl chlorocarbonate(or ethyl chloroformate) is excluded (heading 29.15). (E) Silicic acid esters and their salts (tetraethyl silicate, etc.). This heading does not cover alcoholates or esters of acid-function metal hydroxides, erg., titanium tetra-nbutoxide (also known as tetrabutyl titanate) (heading 29.05). Sub-chapter IX NITROGEN-FUNCTION COMPOUNDS GENERAL This sub-chapter covers nitrogen-function compounds, for example, amines, amides, irnides, but does not cover compounds containing nitro or nitroso groups as the only nitrogen h c t i o n . -
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.