Sourcing rubber peptiser blends from China

Duty and classification for peptiser blends

Read from the UK Trade Tariff on 1 October 2026, heading 3812 covers prepared rubber accelerators, compound plasticisers and anti-oxidising preparations or other compound stabilisers for rubber or plastics. Every supplied line carries 0% duty for goods from China, with no listed anti-dumping or countervailing measure, suspension or attached import control.

The supplied facts do not name peptisers separately. The table shows purchasing forms against the same provisional line, 3812 10 00 90, rather than separate tariff subdivisions. Ask your customs broker to confirm whether that line fits the blend's composition and function. The wider prepared rubber accelerator blends guide covers neighbouring products.

Supply the full formulation, carrier details, safety data sheet and intended function when confirming your commodity code. Do not rely on the supplier's trade name. Review UK REACH obligations for the substances being imported; registration is per substance and per legal entity.

Specify mastication performance and carrier

Specify the active chemistry and content, carrier composition, powder or granule form, moisture, ash and agreed storage conditions. Identify the rubber grade and mastication conditions used for approval. Require the supplier to disclose formulation changes before supplying a replacement grade.

Compare the proposed blend with your approved material in the same rubber and mixing process. Record viscosity reduction, dispersion, mixing behaviour and subsequent cure performance. A matching product name or active content alone is insufficient for approval.

For supply in Great Britain, arrange classification and labelling by someone with scientific competence. Confirm with HSE the registration responsibilities applicable to the substances and annual quantities you plan to import before ordering.

Worked duty example

Illustrative example, not a quote: Illustrative order: 5 tonnes of prepared rubber peptiser blend, assuming classification is confirmed under 3812 10 00 90, invoiced at £32,000 free on board, with £1,600 of freight and insurance to the UK. The customs value is £33,600. Duty at 0% is £0. Import VAT at 20% is charged on the customs value plus duty, £33,600, so it is £6,720. With no duty, the only import tax is the VAT, which a VAT-registered importer can usually reclaim. The import duty and VAT guide explains each step.

Inspection checklist

Composition: compare the batch analysis with the agreed active content, carrier, moisture and ash specification; investigate unexplained changes.

Physical form: check caking, fines, granule consistency and dispersion against the approved sample.

Performance: trial a retained arrival sample under the approved mastication conditions and compare viscosity reduction and cure behaviour.

Packing and records: check seals, batch identification, labels and the English safety data sheet. Keep a retained sample linked to the batch. Use a written inspection brief.

What goes wrong

Watch for carrier substitution, uneven active distribution, moisture pickup and hard agglomerates. These can make dosing and dispersion inconsistent. A blend that works in the supplier's trial may behave differently in your rubber or at your mixing temperature.

Agree acceptance methods before shipment and hold an unexplained batch change for investigation. Separate the purchasing specification from the customs description: a supplier calling a blend a peptiser does not establish its commodity code.

Cambridge China Bridge sources these products for UK businesses, checking the factory and the documents before shipment. See factory verification. For repeat volumes, see container programmes.