Sourcing polymer processing aids from China

Duty and the limits of heading 3812

Read from the UK Trade Tariff on 1 October 2026, every line of heading 3812 carried 0% duty for goods from China. The supplied tariff record lists no anti-dumping or countervailing measures, suspensions or attached import controls.

This guide covers polymer processing aid blends that meet the heading descriptions for compound plasticisers, anti-oxidising preparations or other compound stabilisers. The table shows possible classifications for those functions, rather than a universal processing-aid code. See the wider rubber and plastic additives guide, and the separate acrylic processing aids guide.

Give your customs broker the formulation, ingredient identities, carrier and intended function to confirm the commodity code. Match any specifically listed mixture against its full tariff description. A supplier's grade name alone is insufficient for this check.

Specify the blend around your resin and process

State the base resin, existing additive package, processing method and problem to solve, such as unstable output, surface defects or discolouration. Agree active ingredients, carrier, active content, physical form, moisture and dispersion criteria. Compare the proposed blend with your current grade in your own formulation, using agreed processing conditions and acceptance criteria.

UK REACH registration applies to substances in mixtures, so assess the ingredients rather than treating the blend name as the registration unit. Suppliers must ensure correct labelling and packaging before placing chemicals on the market. Hazardous chemicals supplied for workplace use need a safety data sheet. Obtain the composition statement and an English safety data sheet before approving the order.

Worked duty example

Illustrative example, not a quote: Illustrative: 600 kg of compound stabiliser blend under 3812 39 90 90, invoiced at £3,000 free on board, with £1,600 of freight and insurance to the UK. The customs value is £4,600. Duty at 0% is £0. Import VAT at 20% is charged on the customs value plus duty, £4,600, so it is £920. 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 ingredients, carrier and active content. Investigate any formulation change before releasing the lot.

Physical condition: check moisture, particle consistency, caking and contamination against the approved sample and agreed specification.

Processing trial: compare dispersion, output stability, surface finish and colour with the current blend in the buyer's resin and process.

Packing and records: check sealed bags or drums, batch identification, matching analysis documents and hazard labelling appropriate to the supplied mixture. Keep a retained sample and use the quality inspection guide to brief the inspection.

What goes wrong

A blend can match the supplier's appearance sample but fail in the buyer's resin. Changes to the carrier or active content can alter dispersion and processing behaviour; damp or caked material can feed unevenly. Agree a formulation change approval process and compare incoming batches with the approved trial material.

Paperwork can describe a generic additive while the shipment contains a different formulation. Reconcile the invoice description, composition statement, safety data sheet and batch analysis before shipping. Resolve ingredient-level chemical obligations separately from the tariff rate.

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.