Nail polishes – INCI ingredients and colourants analysed

Nail polish is brushed onto the nail plate in thin layers; the solvents evaporate and leave a coloured or clear film. Base coats are applied first, colour in one or two coats, and top coats on top to add shine. Removal is done with a solvent-based remover, typically based on ACETONE or ETHYL ACETATE. Gel polishes cured under a lamp and peel-off formulas use different chemistry and are labelled accordingly.

Most classic lacquers are built from solvents such as BUTYL ACETATE, ETHYL ACETATE and ISOPROPYL ALCOHOL, the film former NITROCELLULOSE, resins like TOSYLAMIDE/EPOXY RESIN or ADIPIC ACID/NEOPENTYL GLYCOL/TRIMELLITIC ANHYDRIDE COPOLYMER, and plasticisers such as ACETYL TRIBUTYL CITRATE. STEARALKONIUM HECTORITE keeps pigments suspended, and BENZOPHENONE-1 may be included to protect the colour.

Colourants are identified by CI numbers, for example CI 77891 (titanium dioxide) or CI 15850, and must be listed in Annex IV of the EU Cosmetics Regulation. Because brands often use one ingredient list for a whole range of shades, labels may include a “may contain” or “+/-” section listing every colourant used across the range, not only those in your shade.