| 34160 | Isoniazid (INN) | |
| 34160 | Isonicotinic acid | |
| 34160 | Isonicotinic-N-oxide acid | |
| 34140 | Di-''isononyl'' phthalate | |
| 34130 | Iso-octyl alcohol | |
| 34140 | Isopentyl acetate | |
| 34140 | Isophthalic acid | |
| 34110 | Isoprene, not less than 90% pure | |
| 34140 | Isopropyl acetate | |
| 34130 | Isopropyl alcohol | |
| 34170 | 4-Isopropyl-α-methylcinnamaldehyde | |
| 35230 | 4-Isopropyl-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one | |
| 34150 | Isopropylamine | |
| 34110 | Isopropylbenzene | |
| 34130 | 4,4'-Isopropylidenedi-2,6-xylol | |
| 34130 | 4,4'-Isopropylidenediphenol | |
| 34160 | 7-Isopropylquinoline | |
| 34160 | Isoquinoline | |
| 34160 | Isosafrole | |
| 34160 | Isothiocyanates | |
| 33690 | Isotopes, enriched (radioactive) | |
| 33690 | Isotopes, radioactive, natural or artificial (excl. chemical elements occurring naturally in the monoisotopic state, e.g., beryllium 9), and their compounds | |
| 33690 | Isotopes, radioactive, of precious metals | |
| 34260 | Isotopes, stable, pure (excl. chemical isotopes occurring in nature as pure isotopes), and any of their compounds | |
| 34140 | Isovaleric acid and its salts and esters | |
| 91133 | Issuing of building occupation certificates | |
| 71559 | Issuing of currency by non-central banks | |
| 91131 | Issuing of fishing licences | |
| 91131 | Issuing of hunting licences | |
| 91131 | Issuing of tree-felling licences | |
| 01923 | Istle (or ixtle) textile fibres, raw | |
| 26190 | Istle (or ixtle) textile fibres, tow or waste of, whether or not processed but not spun | |
| 03930 | Istle, not prepared for textile use | |
| 34400 | Ivory black | |
| 38999 | Ivory, animal, worked beyond cleaning, simple sawing, cutting (crosswise or lengthwise) and rough planing | |
| 39110 | Ivory, cut crosswise or lengthwise (excl. cut to shape) | |
| 39110 | Ivory, simply sawn to remove useless parts | |
| 39110 | Ivory, unworked or not further worked than simply prepared (excl. cut to shape) | |
| 03930 | Ivory, vegetable, whole or sliced but not otherwise worked | |
| 38999 | Ivory, vegetable, worked or moulded (excl. buttons and blanks therefor) | |