Sourcing liquid silicone rubber from China

6% duty, with narrowly defined suspensions

Read from the UK Trade Tariff on 5 November 2026, heading 3910 covers silicones in primary forms. Liquid silicone rubber generally falls within 3910 00 00 90; specialised formulations may match another listed line. The table includes conditional alternatives, rather than interchangeable classifications. Finished mouldings need classification as finished goods. See the wider silicone guide.

The supplied tariff lines carry 6% duty for goods from China, with no anti-dumping or countervailing measure recorded. Named suspensions give 0%, including specified platinum-catalysed addition-cure liquid mixtures for textile, automotive and electrical applications. The suspension notes also exclude mixtures or preparations containing the listed products: do not assume every platinum-cure grade qualifies. Give your broker the complete formulation and intended use; confirm the commodity code.

The UK Trade Tariff attaches import and export waste controls to these lines. For a China-to-England shipment subject to waste notification controls, shipment can start only after the Environment Agency and other competent authorities consent. Ask your customs broker to confirm whether the material is waste and which requirements apply, particularly for reclaimed or rejected stock.

Specify the cure system and moulding performance

Specify the cure chemistry, component mixing ratio, viscosity of each component, cured hardness, tensile strength, elongation, tear strength, colour and intended moulding process. Agree the cure conditions, any post-curing, shelf life and storage conditions. Request a technical data sheet and a batch certificate of analysis, then trial the material in your own tooling.

Check the UK REACH position of the polymer, monomers and additives with HSE. For supply in Great Britain, chemical classification, labelling and packaging duties apply. Request the safety data sheet for each component. For food-contact applications, confirm the applicable requirements with the relevant food authority; commission testing for the intended use through testing and certification.

Worked duty example

Illustrative example, not a quote: Illustrative order: 5 tonnes of liquid silicone rubber not qualifying for suspension under 3910 00 00 90, invoiced at £17,000 free on board, with £1,400 of freight and insurance to the UK. The customs value is £18,400. Duty at 6% is £1,104. Import VAT at 20% is charged on the customs value plus duty, £19,504, so it is £3,900.80. Import taxes total £5,004.80; a VAT-registered importer can usually reclaim the VAT, so the lasting cost is the £1,104 of duty. The import duty and VAT guide explains each step.

Inspection checklist

Identity: check the component names, grade, batch numbers and production dates against the order and certificates.

Flow: check each component's viscosity against the agreed method and temperature; inspect for separation and contamination.

Cure: make a test slab using the agreed ratio and cure conditions; compare hardness, tensile, elongation and tear results with the approved sample.

Packing: check drum seals, leaks, component pairing and remaining shelf life; retain labelled samples before releasing the batch.

What goes wrong

A satisfactory liquid sample can still produce weak or incompletely cured parts. Catalyst or inhibitor variation, component mix-ups and contamination can change cure behaviour. Accept batches against both uncured viscosity and cured properties, rather than the supplier's grade name alone.

A generic food-grade claim or a report for another formulation does not establish that your material suits the intended application. Match evidence to the formulation and use. Separately, treating all liquid silicone rubber as eligible for the suspension can understate duty: resolve the tariff description before ordering.

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.