CN code 292211 covers aminohydroxynaphthalene sulphonic acids and their salts — aromatic organic compounds bearing simultaneously amino, hydroxyl and sulphonic acid groups attached to the naphthalene ring system. The most commercially significant substances in this group are H acid (1-amino-8-naphthol-3,6-disulphonic acid, CAS 90-20-0), gamma acid (7-amino-1-naphthol-3-sulphonic acid, CAS 87-02-5) and Tobias acid (2-aminonaphthalene-1-sulphonic acid, CAS 81-16-3). These substances are essential intermediates in the synthesis of reactive and acid azo dyes used by the textile dyeing industry, as well as in the manufacture of pigments and photographic chemicals. Classification under CN 292211 requires compliance with Note 1 to Chapter 29 — the substance must be chemically defined and of uniform composition. Commercial blends of these acids with other synthesis intermediates or stabilisers are classified outside Chapter 29, typically in Chapter 38. A certificate of analysis (CoA) confirming chemical identity, purity and CAS number is required at every customs clearance.

Aminohydroxynaphthalene sulphonates imported into the European Union are subject to Regulation (EC) No 1907/2006 (REACH). Non-EU manufacturers must either hold an ECHA registration for the substance at the appropriate tonnage band or appoint an Only Representative (OR) established in the EU to fulfil registration obligations. H acid holds an existing REACH registration — the importer must verify that the registered tonnage band and identified uses cover the intended import volume and application. Under the CLP Regulation (EC) No 1272/2008, substances in this group are typically classified for skin sensitisation and respiratory sensitisation (H317, H334); some naphthalene derivatives may also exhibit mutagenic or carcinogenic properties — the applicable harmonised classification must be verified in Annex VI to CLP. Substances used solely as intermediates in synthesis may benefit from exemptions for on-site isolated intermediates under Article 17 or transported isolated intermediates under Article 18 of REACH, subject to strict conditions of controlled use. A Safety Data Sheet (SDS) prepared in accordance with Regulation (EU) 2020/878 must be provided in the official language of the destination country and must include exposure scenarios as an extended SDS (eSDS). Road transport requirements under ADR must be assessed — most aminonaphthalenesulphonate salts are solid substances classified in Class 9 or may be unregulated at appropriate concentrations.

The customs declaration for goods classified under CN 292211 must state the precise IUPAC name or common trade name (e.g. H acid, Tobias acid), the CAS number, degree of purity, and commercial form (powder, paste, aqueous solution). Required documentation includes a manufacturer-issued certificate of analysis (CoA), a current Safety Data Sheet (SDS) and confirmation of REACH registration or the OR appointment reference. Substances intended for the production of dyes for food contact or children's textiles may be subject to additional product safety requirements under REACH Annex XVII or sector-specific legislation. Export outside the EU should be assessed against Regulation (EU) 2021/821 on dual-use goods controls, although dye intermediates in this group do not generally appear in the control lists. Preferential tariff rates may be available under applicable EU free trade agreements or the GSP scheme — verification in the TARIC database and use of supporting origin documents (EUR.1, invoice declaration) is recommended before each transaction. Where classification is uncertain, a Binding Tariff Information (BTI) ruling should be sought from the competent customs authority.

Organic substances under CN code 2922 11 (Aminohydroxynaphthalene sulphonic acids) require detailed chemical documentation for customs clearance. The Safety Data Sheet must comply with REACH Annex II. Substances classified as hazardous under CLP require GHS pictogram labelling. Transport follows ADR (road) or IMDG (maritime) regulations. Some organic substances may be subject to export controls as dual-use goods. Importers should verify whether the substance requires REACH authorisation (Annex XIV) or is subject to restrictions (Annex XVII).