CN code 320412 covers acid dyes and preparations based thereon, used mainly for dyeing protein fibres (wool, silk) and polyamide fibres (nylon). Acid dyes are sodium salts of sulfonic or carboxylic acids with complex aromatic structures and show good water solubility in acidic media. They are also used in the food industry as food colourants, in cosmetics, and in medical diagnostics. Classification requires confirmation of the chemical character of the dye and its belonging to the acid dye group as defined in Note 3 to Chapter 32. Preparations include ready-to-use acid dye mixtures.

Import of acid dyes is subject to full REACH requirements. Substances must be registered with ECHA, and the importer is required to hold a current Safety Data Sheet. Acid dyes used as food additives are additionally subject to Regulation (EC) No 1333/2008 and must have EFSA authorisation. Acid azo dyes releasing prohibited arylamines are subject to Annex XVII REACH restrictions. CLP labelling must account for all hazards including sensitising and irritant effects. Transport of acid dye solutions is subject to ADR regulations depending on solvent composition and concentration.

Customs declarations for acid dyes under CN code 320412 should include the Colour Index number, CAS number, active substance concentration, and intended product use. For food-grade dyes, additional certification of compliance with the food additives regulation is required. Importers may benefit from EU tariff preferences, including agreements with Turkey, South Korea, and Japan. Export of acid dyes may require dual-use verification, although most products are not on control lists. Import quality control includes testing for heavy metals, arylamines, and dye purity.

When importing Acid dyes and preparations (CN 3204 12) into the EU, VOC content regulations under Directive 2004/42/EC must be considered. Decorative paints and automotive refinish products have established VOC limits. CLP classification requires appropriate GHS pictogram labelling on packaging. Pigments containing heavy metals (lead, cadmium, chromium VI) are subject to strict REACH restrictions (Annex XVII). Importers must have SDS sheets and ensure labelling complies with destination country regulations. Conformity testing may include spectrometric analysis for composition verification.