WCO Explanatory Notes reproduced for reference. © World Customs Organization. Verify against official WCO publication.
28.27 - Chlorides, chloride oxides and chloride hydroxides; bromides and bromide oxides; iodides and iodide oxides. 2827.10 2827.20 - Ammonium chloride - Calcium chloride - Other chlorides : - - Of magnesium 2827.32 - - Of aluminium 2827.35 - - Of nickel 2827.39 - - Other - Chloride oxides and chloride hydroxides : 2827.41 - - Of copper 2827.49 - - Other - Bromides and bromide oxides : 2827.5 1 - - Bromides of sodium or of potassium 2827.59 - - Other 2827.60 - Iodides and iodide oxides 2827.3 1 Subject to the exclusions specified in the introduction to this sub-chapter, this heading covers chlorides, chloride oxides ox chlorides), chloride hydroxides eydrox chlorides , bromides, bromide oxides (oxybromi$es{ iodides and ~odideoxides oxyrodidesy of meta s or of the ammonium ion (Nb'). Halides and halide oxides of non-meta s are excluded (heading 28.12). I I (A) CHLORIDES This group covers the salts of hydrogen chloride (heading 28.06). The main chlorides included here are : (1) Ammonium chloride (sal arnmoniac, ammonium muriate (NH4CI). Results from the neutralisation of hydrogen chloride with ammonia. It may e in crystalline masses or in powder, flowers or cakes obtained b sublimation. Colourless when pure, otherwise yellowish; soluble in water. Its uses inc ude the pickling of metals, in the textile dyeing or rint* industry, in tanning,, as a fertiliser, in the manufacture of LeclanchC cells, for Rardenlng varnishes or glues, m electroplating, in photography (fixing solutions), etc. r See Explanatory Note to heading 31.02 regarding fextilisers containing ammonium chloride. (2) Calcium chloride (CaC12). This compound is either extracted fiom natural Stassfurt salts, or obtained as a by-product of the manufacture of sodium carbonate. It is white, yellowish or brown in colour, according to the degree of purity. A hygroscopic product, it may be in cast or melted form, in porous masses or in flakes, or may be hydrated with 6 H20 (crystalline or granulated). It is used in refligerating mixtures, for cold weather concrete work, as an anti-dust dressing for roads or for hard-earth floorings, as a catalyst, as a dehydratin or condensation agent in organic synthesis (e.g., preparation of amines fiom phenol) an for drying gases. It is also used in medicine. % (3) Magnesium chloride (MgC12). A by-product of the extraction of potassium salts. Occurs either in anhydrous translucent masses, cylinders, tablets or prisms, or hydrated in colourless needles. Soluble in water. Used in the manufacture of very hard cement (e.g., for floor coverings cast in one piece), of cotton or other textile dressings, as a disinfectant or antiseptic in medicine and for fire-proofing wood. The heading excludes natural magnesium chloride (bischofite) (heading 25.30). (4) Aluminium chloride AlC13). Obtained by the action of chlorine on aluminium, or of hydrogen chloride on umin~umoxide. Anhydrous or crystalline; or in aqueous solutions of s p p y consistent . The anhydrous salt fumes on ex osure to air. The solid chloride is use m organic synt iesis, as a mordant in dyeing, etc. aqueous solutions it is used for preserving wood, pickling wool, as a disinfectant, etc. % (5) Iron chlorides. (a) Ferrous chloride (FeC12). Anhydrous (scales, flakes or greenish-yellow powder) or hydrated with, for example, 4 H20 (green or bluish crystals); or may be in green aqueous solutions. Oxid~sesin the air and becomes yellow. Usually presented in carefully stoppered bottles with a few drops of alcohol added to prevent oxidation. A reducing agent and a mordant. (b) Ferric chloride (FeC13). Prepared by dissolving iron oxide or carbonate or iron metal in hydrochloric acid or in aqua regia, or by passing gaseous chlorine over red-hot iron. Anhydrous, in yellow, brown or garnet-coloured masses, deli uescent and soluble in water, or hydrated (with 5 or 12 HzO) in orange-coloured, re or purple crystals; the liquid iron chloride on the market is a dark red ueous solution. More widely employed than ferrous chloride, e.g., for purifying in ustrial water, as a mordant, in photography and photo-engraving, to give a atlna to iron, in medicine (haernostatic or y, as an oxidising agent. vasoconstrictive preparations), and, pnncipal? "r4 (6) Cobalt dichloride (cobaltous chloride) (CoC12.6H20). In pink, red or purple crystals turning blue when heated; soluble in water. Used in the manufacture of hygrometers, as a sympathetic ink or as an absorbent in gas masks. (7) Nickel dichloride (NiCh). Anhydrous, in ellow scales or flakes, or hydrated (with 6 H20) in deliquescent green crystals; very solu le in water. Used as a mordant in dyeing, in electrolysis (nickel-plating baths) or as an absorbent in gas masks. r, (8) Zinc chloride (ZnC12). Zinc chloride is obtained by passin hydrogen chloride over roasted lende or calamine) (heading 26.08); or ~t can e extracted fiom the ashes and zinc Ores c assified in heading 26.20. White crystalline masses (butter of zinc fused or residues granulated. It is highly deliquescent, soluble in water, caustic and very toxic. sed as an antiseptic, fun icide, dehydratin agent, for fire-proofing wood, preserving hides, hardening cell ose weparation o vulcanised fibre), and in organic s thesis. Also used as a flux in soldering, as a mordant in dyeing or rinting, for puriFn oils, and in the manufacture of dental cements or of medicaments gauterising antiseptic$ % ib b P (9) Tin chlorides. (a) Stannous chloride (tin dichloride) (SnC12). Masses with a resinous fracture, or in white or yellowish crystals (with 2 HzO). Also in solutions of the same colours. Corrosive; deteriorates in the air. Used as a reducing agent or mordant in textile dyeing, in vat dyes (dyers' tin salt), as tin size for silk or in electro1ytic tin-plating. (b) Stannic chloride tin tetrachloride) (SnC14). In the anh drous state this is a colourless or yellowish liqui , giving off white fumes in a humi atmosphere. Hydrated it gives colourless crystals; it also occurs in gelatinous masses (butter of tin). Used as a textile mordant or slze (tin size for silk), or, mixed with stannous chloride and gold salts, in the preparation of purple of Casslus for decorating porcelain. dY (10) Barium chloride (BaC12). Prepared from natural barium carbonate (witherite) or sul hate arytes . Soluble in water; may be anhydrous or fused (yellow powder), or hydratodlwith !?H20 )in lamellar crystals or tablets). Used in dyeing, in ceramics, as a parasiticide or rat-poison, for purifying industrial water, etc. (1 1) Titanium chlorides. The most important is titanium tetrachloride (TiCb) obtained in the metallurgy of titanium by the action of chlorine on a mixture of carbon and native titanium dioxide (rutile, brookite, anatase). Colourless or ellowish Zi uid with a pungent odour; fumes in moist air; absorbs and is hydrolysed y water. sed in the manufacture of mordants for dyeing (titanium mordants), for giving ceramics an iridescent appearance, for making smoke-screens or in organic synthesis. g (12) Chromium chlorides. (a) Chromous chloride (CrC12).Needle-shaped crystals or azure-blue solutions. Reducing agent. (b) Chromic chloride (CrC13). Pink or orange crystalline scales, or hydrated (with 6 or 12 HzO) in green or purple crystals. Used as a mordant in textile dyeing, in taming, in electrolytic chromium plating, in organic synthesis and for preparing sintered chromium. (13) Manganese dichloride MnC12). Obtained by treating the natural carbonate, rhodocrosite or dialo ite (headin 2 .02) with hydrogen chloride. Rose-coloured, crystalline masses when Aydrous; or ydrated (e.g., with 4 H20) in rose-coloured crystals, deliquescent and soluble in water. Used in the manufacture of brown colouring agents or of certain medicaments, as a catalyst and in textile printing. f (14) Copper chlorides. (a) Cuprous chloride (cop er monochloride) (CuCl). Crystalline owder or colourless crystals, practicalfy lnso uble in water, oxidising in the air. Use in the metallurgy of nickel and silver, or as a catalyst. I? B (b) Cupric chloride (CuC12.2H20). Deliquescent green crystals, soluble in water. Used in textile printing, photogra hy or electrolysis; as a catalyst, an antiseptic, disinfectant or insecticide; in the dyestu! if industry and xn pyrotechnics (Bengal fires). Nantokite, natural copper chloride, falls in heading 25.30. (15) Antimony chlorides. (a) Antimony trichloride butter of antimony) (SbC13). Prepared by treating natural sulphide (stibnite) (hea 'ng 26.17) with hydrogen chloride. Occurs in colourless, translucent lum s; absorbs atmospheric moisture to take on an unctuous appearance; it is caustic. Use for " bronzing " or pickling metals, as a mordant, for malang lakes, for leather dressing, and in the preparation of antimony oxide or veterinary remedies. 6, (b) Antimony pentachloride (SbC15). Colourless liquid, fuming in moist air; decomposed by water. Used as a chlorine carrier in organic synthesis and as a fumigant. This group excludes sodium chloride and potassium chloride which, even in the pure state, fall in headings 25.01 and 31.04 or 31.05, respechvely. The heading also excludes the corn ound wrongly known as "chloride of lime" which is commercial calcium hypochlorite (heading 2 .28). Mercury chlorides (mercurous chloride and mercuric chloride) fall in heading 28.52. D (B) CHLORIDE OXIDES AND CHLORIDE HYDROXIDES This up covers chloride oxides (oxychlorides) and chloride hydroxides (hydroxychlorides) of metar It includes : (1) Copper chloride oxides and chloride hydroxides. Crystalline, blue powders, used as insecticides, fungicides or pigments. The heading excludes natural copper chloride hydroxide (atacamite) (heading 26.03). (2) Aluminium chloride hydroxide (A12C1(OH)5.xH20).Yellowish-white powder. Used as anti-perspirant in cosmetics. (3) Chxomium chloride oxide (chromyl chloride) (CrC1202). Red liquid with an irritating odour; fumes in moist air and decomposed by water. Used in tanning, as a mordant and as an oxidising agent. (4) Tin chloride oxide. Grey or white amorphous lumps, soluble in water. Used as a mordant. (5) Antimony chloride oxide (SbCIO). A white powder used in the manufacture of smokes, pigments, medicaments. (6) Lead chloride oxides and chloride hydroxides. White powders obtained by treating lead oxide litharge) with an alkaline chloride. Used for preparing lead chromates, as pi (Casse yellow) for water paints, oil paints or distempers, and in the preparation o other more complex pigments. I $ments (7) Bismuth chloride oxide (bismuthyl chloride) (BiC10). White powder used as a pigment (" pearl white ") in the manufacture of artificial pearls. (C) BROMIDES AND BROMIDE OXIDES This group covers the salts of hydrogen bromide (heading 28.11) and bromide oxides (oxybromides). (1) Sodium bromide (NaBr). Prepared in a similar way to ammonium bromide, or by treating with a sodium salt the iron bromide obtained by direct action of bromine on iron turnings. It can be obtained in the rather unstable anhydrous state by c stallisation above 51 C. When crystallised below that temperature it is h drated (wit 2 H20), in large cubic crystals. Colourless, hygroscopic, soluble in water. 6sed in medicine and m photography. (2) Potassium bromide (KBr). Similar manufacturing processes and same uses as sodium bromide. Anhydrous, in large crystals. (3) Ammonium bromide W r ) . Produced by the action of hydrogen bromide on ammonia. Colourless crystals, soluble m water, turning yellow and slowly disintegratin exposed to air, and volatilised by heat. Used in medicine as a sedative, in photograp$ywhen (as a restrainer in developing solutions), and as a fireproofing material. (4) Calcium bromide (CaBr2.6H20 . Prepared from calcium carbonate and hydrogen bromide; deliquescent colourless crysta s, very soluble in water. Used in medicine and in photography. I (5) Copper bromides. (a) Cuprous bromide (CuBr). Obtained by reduction of cupric bromide; colourless crystals, insoluble in water. Used in organic synthesis. (b) Cu ric bromide (CuBr2). Prepared by direct action of bromine on co per. De iquescent crystals, soluble in water. Used in organic synthesis and in photograp y. P !I (6) Other bromides and bromide oxides. These include strontium bromide (used in medicine), and barium bromide. (D) IODIDES AND IODIDE OXIDES This group covers the salts of hydrogen iodide (heading 28.11) and iodide oxides (oxyiodides). (1) Ammonium iodide W I ) . Obtained by the action of hydrogen iodide on ammonia or ammonium carbonate. White, crystalline, hygrosco ic powder, very soluble in water. Used in medicine (for circulatory ailments or emphysema? and in photography. (2) Sodium iodide (NaI). Obtained by the action of hydro en iodide on sodium hydroxide or carbonate, or by treating with a sodium salt the iron i d d e obtained by the direct action of iodine on iron filings; also prepared by calcining iodates. Crystalline, anhydrous. Deliquescent and ve soluble in water, decom osing on exposure to air and light. Used in medicine, to iodise ta le or kitchen salt and in p otography. X \ (3) Potassium iodide (KT). Similar manufacturing processes and similar uses, but keeps better than sodium iodide. Anhydrous, colourless or opaque crystals. (4) Calcium iodide (Ca12). Prepared .from calcium carbonate and hydrogen iodide. Colourless shiny crystals or pearly white scales. Soluble in water and turns yellow in the air. Used in photography. (5) Other iodides and iodide oxides. These include : (a) Iodides of lithium (used in medicine), of strontium, of antimon of zinc or of iron (both used in medicine and as antiseptics), of lead (with a met&c glint, used in the preparation of rubber colours), of bismuth (reagent). (b) Antimony iodide oxide, copper iodide oxide and lead iodide oxide. Mercury iodides (mercurous iodide and mercuric iodide) are excluded (heading 28.52).
Notes. 1.- Except where the context otherwise requires, the headings of this Chapter apply only to : (a) Separate chemical elements and separate chemically defined compounds, whether or not containing impurities; (b) The products mentioned in (a) above dissolved in water; (c) The products mentioned in (a) 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; (d) The products mentioned in (a), (b) or (c) above with an added stabiliser (including an anti-caking agent) necessary for their preservation or transport; (e) The products mentioned in (a), (b), (c) or (d) above with an added anti-dusting agent or a colouring substance 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. 2.- In addition to dithionites and sulphoxylates, stabilised with organic substances (heading 28.31), carbonates and peroxocarbonates of inorganic bases (heading 28.36), cyanides, cyanide oxides and complex cyanides of inorganic bases (heading 28.37), fulminates, cyanates and thiocyanates, of inorganic bases (heading 28.42), organic products included in heading 28.43 to 28.46 and 28.52 and carbides (heading 28.49), only the following compounds of carbon are to be classified in this Chapter : (a) Oxides of carbon, hydrogen cyanide and fulminic, isocyanic, thiocyanic and other simple or complex cyanogen acids (heading 28.11); (b) Halide oxides of carbon (heading 28.12); (c) Carbon disulphide (heading 28.13); (d) Thiocarbonates, selenocarbonates, tellurocarbonates, selenocyanates, tellurocyanates, tetrathiocyanatodiamminochromates (reineckates) and other complex cyanates, of inorganic bases (heading 28.42); (e) Hydrogen peroxide, solidified with urea (heading 28.47), carbon oxysulphide, thiocarbonyl halides, cyanogen, cyanogen halides and cyanamide and its metal derivatives (heading 28.53) other than calcium cyanamide, whether or not pure (Chapter 31). 3.- Subject to the provisions of Note 1 to Section VI, this Chapter does not cover : (a) Sodium chloride or magnesium oxide, whether or not pure, or other products of Section V; (b) Organo-inorganic compounds other than those mentioned in Note 2 above; (c) Products mentioned in Note 2, 3, 4 or 5 to Chapter 31; (d) Inorganic products of a kind used as luminophores, of heading 32.06; glass frit and other glass in the form of powder, granules or flakes, of heading 32.07; (e) Artificial graphite (heading 38.01); 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; cultured crystals (other than optical elements) weighing not less than 2.5 g each, of the halides of the alkali or alkaline-earth metals, of heading 38.24; (f) Precious or semi-precious stones (natural, synthetic or reconstructed) or dust or powder of such stones (headings 71.02 to 71.05), or precious metals or precious metal alloys of Chapter 71; (g) The metals, whether or not pure, metal alloys or cermets, including sintered metal carbides (metal carbides sintered with a metal), of Section XV; or (h) Optical elements, for example, of the halides of the alkali or alkaline-earth metals (heading 90.01). 4.- Chemically defined complex acids consisting of a non-metal acid of sub-Chapter II and a metal acid of sub-Chapter IV are to be classified in heading 28.11. 5.- Headings 28.26 to 28.42 apply only to metal or ammonium salts or peroxysalts. Except where the context otherwise requires, double or complex salts are to be classified in heading 28.42. 6.- Heading 28.44 applies only to : (a) Technetium (atomic No. 43), promethium (atomic No. 61), polonium (atomic No. 84) and all elements with an atomic number greater than 84; (b) Natural or artificial radioactive isotopes (including those of the precious metals or of the base metals of Sections XIV and XV), whether or not mixed together; (c) Compounds, inorganic or organic, of these elements or isotopes, whether or not chemically defined, whether or not mixed together; (d) Alloys, dispersions (including cermets), ceramic products and mixtures containing these elements or isotopes or inorganic or organic compounds thereof and having a specific radioactivity exceeding 74 Bq/g (0.002 μCi/g); (e) Spent (irradiated) fuel elements (cartridges) of nuclear reactors; (f) Radioactive residues whether or not usable. The term “isotopes”, for the purposes of this Note and of the wording of headings 28.44 and 28.45, refers to : - individual nuclides, excluding, however, those existing in nature in the monoisotopic state; - mixtures of isotopes of one and the same element, enriched in one or several of the said isotopes, that is, elements of which the natural isotopic composition has been artificially modified. 7.- Heading 28.53 includes copper phosphide (phosphor copper) containing more than 15 % by weight of phosphorus. 8.- Chemical elements (for example, silicon and selenium) doped for use in electronics are to be classified in this Chapter, provided that they are in forms unworked as drawn, or in the form of cylinders or rods. When cut in the form of discs, wafers or similar forms, they fall in heading 38.18. Subheading Note. 1.- For the purposes of subheading 2852.10, the expression “chemically defined” means all organic or inorganic compounds of mercury meeting the requirements of paragraphs (a) to (e) of Note 1 to Chapter 28 or paragraphs (a) to (h) of Note 1 to Chapter 29.