Buying THF in the EU: REACH, CLP Labelling & TARIC 6.5% Duty

Tetrahydrofuran (THF, CAS 109-99-9, EC 203-726-8) is a clear, mobile, hygroscopic cyclic ether with a normal boiling point of 65–66 °C, a closed-cup flash point of approximately -14 °C, and a vapour pressure of about 19.3 kPa at 20 °C. It is purchased in the EU as a reaction solvent, polymerisation medium, resin carrier, extraction solvent, and intermediate. A buyer placing THF on the EU market as a substance or in a mixture is exposed to three regulatory gates: registration and supply-chain duties under Regulation (EC) No 1907/2006 (REACH), hazard communication and packaging under Regulation (EC) No 1272/2008 (CLP), and customs treatment under TARIC code 2932 11 00 00, where the conventional third-country duty is 6.5% ad valorem.

Commercial THF supplied within the EU is not a single-parameter commodity. Published supplier specifications commonly list assay at or above 99.9 wt%, water below 0.05 wt%, and peroxide content below 50 mg/kg as H₂O₂. Stabilised grades contain radical-trapping inhibitors such as butylated hydroxytoluene at concentrations often in the range 100–250 mg/kg. The inhibitor identity and concentration are not inert details: residual phenolic stabilisers can poison sensitive polymerisation catalysts downstream, while uninhibited material develops explosive peroxides during storage in air. Both stabilised and unstabilised THF therefore require specification control before import or purchase.

What REACH registration duties arise when THF crosses the EU border?

Under Article 6(1) of REACH, any legal entity importing THF into the EU in quantities of 1 tonne per year or more must hold a registration for that substance unless the non-EU manufacturer has designated an only representative under Article 8. The 1 t/a threshold is calculated per legal entity, not per customs declaration or per site, and it covers THF imported as a substance, as a component of a mixture, or in articles with intended release. Registration tonnage determines the information requirements set out in Annexes VII to X: imports at 1–10 t/a require the Annex VII data set, while higher tonnage bands add physicochemical, toxicological, and ecotoxicological endpoints.

For a buyer sourcing THF from an EU distributor, the registration number of the upstream registrant should appear in section 1.1 of the safety data sheet. The buyer retains downstream user obligations under Title V of REACH, including verifying that its own uses and operational conditions are covered by the supplier’s exposure scenarios. If a use is outside the conditions in the extended safety data sheet, Article 37(4) requires the downstream user to carry out a chemical safety assessment; Article 38(1) requires reporting to ECHA before commencing a use that is not covered. In practice, many THF buyers in polymerisation and coatings operations must check exposure scenarios for closed-system transfer, ventilation rate, duration of exposure, and maximum daily throughput against site-specific values.

When a non-EU producer has not appointed an Article 8 only representative

If THF is purchased from a producer outside the EU and no only representative has been appointed, the EU importer becomes the registrant under REACH. This triggers the full registration duties: access to required data, preparation of a chemical safety report for volumes at or above 10 t/a, and submission to ECHA through REACH-IT. The importer may need to join a substance information exchange forum or purchase a letter of access from the lead registrant. Article 27 requires data sharing with previous registrants; cost-sharing disputes are governed by ECHA decisions. A written contract with the non-EU supplier should state whether an only representative exists, whether the EU buyer is considered a downstream user or importer, and who owns the registration number for future tonnage increases.

THF is not listed in REACH Annex XIV, so authorisation under Title VII is not currently required. Nor does the substance appear in the Candidate List for authorisation. Nevertheless, a buyer should verify the absence of REACH Annex XVII restrictions for the intended use at the time of purchase, because restriction entries can change and can apply to specific solvent uses, consumer mixtures, or workplace exposure conditions.

CLP classification and label elements for drums, IBCs, and bulk ISO tanks

The harmonised classification for THF appears in Annex VI Part 3 of CLP under index number 603-025-00-0. The substance is classified as Flam. Liq. 2, Eye Irrit. 2, STOT SE 3, and Carc. 2. The flash point below 23 °C and initial boiling point above 35 °C place the material in flammable liquid category 2. The label must therefore carry the signal word “Danger,” the GHS pictograms GHS02, GHS07, and GHS08, and the hazard statements shown below.

Under CLP Article 17, hazardous substances may not be placed on the market unless packaging is labelled and, where required, child-resistant and tactile-warning compliant. For THF in mixtures, the CLP generic concentration limits trigger labelling at 1% or higher for carcinogenicity category 2, and at 20% or higher for flammable liquid category 2 under the standard mixture rules, unless specific concentration limits are assigned. A buyer should also verify the safety data sheet against Annex II of REACH as amended by Regulation (EU) 2020/878, particularly sections 2, 7, 9, and 10.

Peroxide accumulation in THF storage is a direct thermal hazard when distillation or jacket heating is used. The ether oxygen adjacent to the ring makes THF prone to autoxidation at the α-carbon. Stabilised grades rely on radical-trapping inhibitors such as butylated hydroxytoluene, but the stabiliser is consumed over time. Uninhibited material stored in partially empty drums at ambient temperature can accumulate peroxides, which are polar and concentrate during distillation. Any drum with unknown inhibitor status, visible crystal formation at the cap, or a peroxide test strip result above 50 mg/kg as H₂O₂ should not be opened or heated. Closed-loop sampling and nitrogen-blanketed tanks with head-space oxygen below 5 vol% are standard engineering controls. Transfer lines should use stainless steel or PTFE construction; elastomer compatibility must be confirmed against supplier chemical resistance data because THF swells many common gasket polymers.

The TARIC rate for THF is 6.5% unless a preferential origin applies

Tetrahydrofuran is classified under CN code 2932 11 00, covering heterocyclic compounds with oxygen hetero-atom only, containing an unfused furan ring. In the EU TARIC database, the ten-digit code 2932 11 00 00 carries an erga omnes third-country duty of 6.5%. The duty is ad valorem and is applied to the customs value determined under Articles 69–74 of Regulation (EU) No 952/2013 (Union Customs Code). The customs value normally includes the price paid or payable, freight, insurance to the EU border, and certain royalties or assists where applicable. Import VAT then applies at the member state rate under Council Directive 2006/112/EC.

Customs clearance requires an EORI number and a correct single administrative document. The importer must declare the commodity code, origin, and customs value. Incorrect classification can lead to post-clearance recovery under Article 105 of the Union Customs Code. A preferential origin declaration under a free trade agreement or the Union’s Generalised Scheme of Preferences may reduce or eliminate the 6.5% rate, but origin is not determined by shipment location; the product must meet the relevant origin rules and proof requirements. The TARIC console should be checked for the valid measure on the day of declaration because tariff measures, quotas, or suspensions can change.

Transport documentation for THF must reflect UN 2056, Class 3, Packing group II. Drums, IBCs, and ISO tanks must be closed, electrically bonded, and labelled with the CLP hazard pictograms and the UN labels required by ADR/RID/IMDG. For bulk ISO tanks, the vapour space should be inerted with nitrogen, and the tank should be grounded during unloading. The buyer should also verify that the packaging is tamper-evident and that the supplier has provided the required safety data sheet before first consignment delivery, not after arrival.

Analytical release testing for polymerisation-grade THF normally includes gas chromatographic assay, water by Karl Fischer titration using ASTM E203 or ISO 760, peroxide by iodometric titration, and colour by platinum-cobalt scale ISO 6271. A workable incoming specification should fix water below 0.05 wt% for moisture-sensitive anionic polymerisation, peroxide below 50 mg/kg as H₂O₂ for distillation safety, and non-volatile residue below 10 mg/kg for high-purity or electronic-grade applications. For catalytic processes, the certificate of analysis should also state the inhibitor identity and concentration because residual stabiliser can alter catalyst activity and selectivity in ways that are not visible from assay or water content alone.