WCO Explanatory Notes reproduced for reference. © World Customs Organization. Verify against official WCO publication.
29.17 - Polycarbo lic acids, the5 anhydrides, halides, peroxides and peroxyacids; their halogenat$ sulphonated, nitrated or nitrosated derivatives. - Acyclic olycarboxylic acids, their anhydrides, halides, peroxides, peroxyacijs and their derivatives : 2917.1 1 - - Oxalic acid, its salts and esters - - Adipic acid, its salts and esters 29 17.13 - - Azelaic acid, sebacic acid, their salts and esters 2917.14 - - Maleic anhydride 2917.19 - - Other 2917.20 - Cyclanic, cyclenic or cycloterpenic olycarboxylic acids, their anhydrides, 2917.12 K halides, peroxides, peroxyacids and t eir derivatives - Aromatic polycarbox lic acids, their anhydrides, halides, peroxides, peroxyacids and their ci! erivatives : 2917.32 - - Dioctyl orthophthaIates 2917.35 - - Dinonyl or didecyl orthophthalates - - Other esters of orthophthalic acid - - Phthalic anhydride 2917.36 -- 29 17.37 - - Dimethyl terephthalate - - Other 2917.33 2917.34 2917.39 Terephthalic acid and its salts This heading covers pol carboxylic acids and their anhydrides, halides, peroxides, J'er0xyacids7 i esters and salts, as we 1 as the halogenated, sulphonated, nitrated or nitrosate derivatives (including compound derivatives) of any of these products. (A) ACYCLIC POLYCARBOXYLIC ACIDS AND THEIR ESTERS, SALTS AND DERIVATIVES (1) Oxalic acid (HOOCCOO . Fine crystals, colourless, transparent and odourless; toxic. Used as a bleaching agent or textiles and for hides, as a mordant in the textile industry, and in organic synthesis. '3 Its main salts are ammonium, potassium, sodium, calcium, iron and ammonium-iron oxalates. Its main esters are dimethyl and diethyl oxalates. (2) Adipic acid (HOOC(CH2)4COOH).Crystallises in colourless needles; used, inter alia,for the manufacture of some plastics such as polyamides. (3) Azelaic acid. Yellowish to white crystalline owder; used, infer alia,for preparing plastics (alkyd resins, polyamides, polyurethanes) an in other organic syntheses. S (4) Sebacic acid. White leaflets; used, inter alia, as stabiliser in lastics (in alkyd resins, maleic and other polyesters, polyurethanes); in the manufacture o plastics. P (5) Maleic anhydride. Colowless crystalline mass; used for preparing plastics (polyesters) and in other organic syntheses. (6) Maleic acid (HOOCCH=I:HCOOH). Large colourless crystals or in cast blocks; used, inter aEia, for the preparatichn of certain plastics (e.g., polyesters). (7) Malonic acid (HOOCCH2C100H).Crystallises in large colourless flakes. The most important esters include diethyl malonate, which is used in organic syntheses (e-g.,of medicaments such as the barbiturates). (8) Succinic acid (HOOCC(C:H2)2COOH). Colourless, odourless and transparent crystals. Used in organic synthesis. CYCLANIC, CYCLENIC OR CYCLOTERPENIC bB)OLYCARBIDXYLIC ACIDS AND THEIR ESTERS, SALT'S AND OTHER DERIVATIVES (C) AROMATIC POLYCARBOXYLIC ACIDS AND THEIR ESTERS, SALTS AND OTHER DERIVATIVES (1) Phthalic anhydride (C&lI(C0)20). Crystallises in translucent white needles, crystalline masses or white flakes; very li organic synthesis (of plastics (a1 and voluminous, with a characteristic odour. Used in resins) and of plasticisers, etc.). I T (2) Benzenedicarboxylic acids (0-, m-, p-) (C6& COO 2). Ortho-benzenedicarboxylic acid is commonlv called nhthalic acid (ortho-nhtha ic acid . Meta-benzenedicarboxvlic acid is r commonl &lled isobhthalic acid, and pdra-bcnzened~carboxylicacid is cornmbnly called . . They are used for preparing synthetic colouring matter, plastics tcrcphtha ic acid..Crystals. . (alkyd resins) and plasticisers. (3) Dichlorophthalic and tetrachlorophthalic acids and their anhydrides.
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.