Hydrochloric acid, identified by CAS 7647-01-0 and EC 231-595-7, enters the European Economic Area under the harmonised CLP entry for hydrogen chloride, Index 017-002-00-2. The REACH and CLP Obligations for HCl: What Exporters to Europe Must Do are concentrated in registration, only representative appointment, hazard communication, classification notification, and poison centre submission. Shipments that are not covered by a valid EU importer registration or an only representative appointment breach REACH Article 5 and may be detained at customs. Because hydrogen chloride is registered at high tonnage, the main commercial burden is data-sharing and documentation rather than generation of new vertebrate data.

Regulatory Status of EC No. 231-595-7 Under REACH

Under Regulation (EC) No 1907/2006, Article 5 prohibits placing on the market any substance above 1 t/a unless registered. Article 6 imposes registration on EU manufacturers and importers; Article 8 permits a non-EU manufacturer to appoint an only representative. Hydrochloric acid is not exempt under Annex IV or Annex V, and it is not subject to authorisation under Annex XIV or restriction under Annex XVII. The ECHA disseminated dossier for hydrogen chloride reflects a high-tonnage registration under REACH Annex X. New registrants therefore join the existing joint submission under Article 11 and negotiate a letter of access with the lead registrant. An opt-out under Article 11(3) is possible but requires justification that joint submission would be disproportionately costly or would risk confidential business information. The registration dossier must include the Annex VII to X information package corresponding to the tonnage band; for high tonnage, this includes physicochemical, toxicological, and ecotoxicological endpoints. The exact registration fee and letter of access cost are not published by ECHA and depend on the lead registrant’s data-sharing arrangement.

Tonnage is calculated on the anhydrous hydrogen chloride equivalent if the exported solution is aqueous. A 30% hydrochloric acid solution contains 30 kg hydrogen chloride per 100 kg solution. Exporters must not report solution weight as substance weight. Imports below 1 t/a of the substance still trigger CLP duties if the solution is hazardous, even though REACH registration does not apply. Data-sharing under REACH Articles 27 and 30 includes a dispute resolution process if the lead registrant refuses access. The non-EU exporter should secure the letter of access before commercial shipments, because registration is a legal precondition, not a post-shipment formality.

For aqueous hydrochloric acid, the binding classification under CLP Annex VI is driven by the hydrogen chloride concentration. The harmonised entry assigns Skin Corr. 1B, H314 at ≥25%; Skin Irrit. 2, H315 and Eye Irrit. 2, H319 between 10% and 25%; and STOT SE 3, H335 at ≥10%. These specific concentration limits are legally binding and override generic concentration limits. Self-classification against the same entry is not permitted where the harmonised limits apply.

At 37% commercial strength, the label carries the GHS05 pictogram, signal word Danger, H314, and the precautionary statements P260, P264, P280, P301+P330+P331, P303+P361+P353, P305+P351+P338, and P310. At 10% to 25%, H315 and H319 replace H314, and the signal word is Warning with the GHS07 pictogram. Below 1%, no harmonised classification normally applies, but the aqueous solution may still require local environmental or transport classification depending on pH and member state requirements.

If the EU importer is not required to register because the annual volume is below 1 t/a, CLP Article 40 requires notification to the C&L inventory within one month of placing the substance on the market. The notification includes the classification, labelling, and any specific concentration limits. If the importer has registered the substance under REACH, the classification information is already in the registration dossier and no separate C&L notification is required. A non-EU exporter has no direct duty to submit a C&L notification; the duty falls on the EU importer or only representative.

How Does the Only Representative Mechanism Alter Exporter Liability?

Under REACH Article 8, a non-EU producer of hydrochloric acid may appoint an only representative established in the EU/EEA. The appointment must be written, must identify the non-EU manufacturer and the only representative, and must define the tonnage and uses covered. Once the only representative submits the registration, EU importers receiving the product become downstream users. The exporter is not released from data supply obligations: all use descriptors under the ECHA guidance R.12 system—sector of use, product category, process category, environmental release category—must be communicated to the only representative before the chemical safety report is finalised. If an intended European use is not covered by the exposure scenario, the importer may be forced to prepare a downstream user chemical safety report under REACH Article 37, or the only representative must update the dossier under Article 22. A registration number issued to an EU importer does not cover shipments to a different legal entity. A non-EU exporter using an only representative should therefore instruct its EU customers that their downstream user status applies only for product sourced from that specific non-EU manufacturer.

An only representative cannot delegate the registration duty to a non-EU entity; the only representative must have sufficient technical competence and access to a REACH-IT account. If the only representative ceases operations, the registration is no longer valid, and shipments to EU importers lose downstream user status. Exporters should include termination and data-transfer clauses in the only representative appointment.

Safety data sheet duties run in parallel with registration. REACH Article 31 requires an SDS for hydrochloric acid because it meets the CLP classification criteria; the SDS must conform to Annex II as amended by Regulation (EU) 2020/878 and be supplied in the official language of the member state where the product is placed on the market. Section 2.2 must reproduce the harmonised label elements, including H314 or H315/H319/H335 as applicable. For aqueous hydrochloric acid supplied as a mixture, Section 3.2 must list hydrogen chloride at the exact weight percentage; for anhydrous hydrogen chloride, Section 3.1 applies. When the substance is registered at or above 10 t/a, the SDS must be accompanied by an exposure scenario in an annex, in accordance with REACH Article 31(7) and Annex II, Section 16. The exposure scenario must include operational conditions and risk management measures for each contributing scenario. A documented use that is absent from the exposure scenario is a compliance gap; it cannot be resolved by deleting the use from purchase records.

Under Article 31(9), suppliers must update the SDS without delay after new hazard or risk management information becomes available. Language obligations under Article 31(5) are not satisfied by an English-only SDS in member states where another official language is required. The SDS Section 2.3 should note that hydrogen chloride is corrosive to the respiratory tract if mists are generated; ventilation requirements in Section 8.2 should align with national occupational exposure limits, which vary by member state.

When Aqueous Hydrogen Chloride Falls Below 25%, Labelling and Packaging Shift

The 25% threshold is the main boundary between corrosivity and irritation, but it is not the only compliance trigger. At 10% to 25%, H315, H319, and H335 are assigned; at ≥25%, H314 applies and the product must be packaged and labelled as corrosive. For concentrated hydrochloric acid supplied to the general public, CLP Annex II imposes child-resistant fastening and a tactile warning of danger; the tactile warning device should meet EN ISO 11683. Industrial packaging does not automatically require child-resistant closures unless national law applies. The concentration also changes the UN transport description in SDS Section 14: hydrochloric acid is class 8, UN 1789, and packing group assignment depends on the actual strength under the applicable modal regulation. Exporters should ensure that the CLP label and the UN transport documentation do not contradict each other, particularly for 25% to 36% commercial solutions where both corrosive and irritant classifications can appear on different documents if the exact specification is not stated.

The harmonised entry for hydrogen chloride includes Press. Gas, H280 and Acute Tox. 3, H331 for the anhydrous gas. Aqueous solutions below fuming concentration are not pressure-liquefied and are not assigned these two classes through the harmonised entry. Exporters of fuming hydrochloric acid should evaluate whether the product releases hydrogen chloride vapour at a concentration that triggers acute inhalation classification. Published data for this specific configuration is limited; the assignment depends on vapour pressure at the shipping temperature and should be confirmed by a qualified CLP assessor.

When aqueous hydrochloric acid is placed on the market as a hazardous mixture, CLP Article 45 and Annex VIII require a poison centre notification through the ECHA Submission portal before the mixture is placed on the market in each member state. The notification must include the UFI, the trade name, the exact hydrogen chloride concentration range, packaging details, and use category. The UFI must be printed on the label in an unobstructed location and must be preceded by the acronym “UFI”. For industrial-only hydrochloric acid, the harmonised notification deadline was 1 January 2025. Consumer and professional uses were subject to earlier deadlines. Anhydrous hydrogen chloride gas supplied as a substance is outside the UFI poison centre mechanism, but the C&L inventory and REACH duties remain. Exporters should generate the UFI using the ECHA UFI generator and not use a generic identifier; each mixture composition requires a UFI. The UFI must also be included in SDS Section 1.1 for hazardous mixtures.

Tonnage Band Compliance and Customs Verification Are Not Static

Customs enforcement under the EU Single Window can flag missing REACH registration numbers or absent UFI data. Penalties are determined by member state law and may include detention, destruction, and fine. Tonnage band changes during a calendar year must be reflected in a dossier update under REACH Article 22. The only representative must maintain the dossier with current composition, classification, tonnage, and use information. A registration number belonging to a different legal entity, a lapsed only representative, or a dossier with outdated concentration ranges is treated as non-compliant. Exporters should retain documented evidence of letter of access, only representative appointment, SDS language versions, and UFI placement; these records are the first items requested during an ECHA or national authority inspection.