Sourcing vinyl silicone fluids from China

6% for neat fluids; narrow 0% suspensions

Read from the UK Trade Tariff on 1 October 2026, heading 3910 covers silicones in primary forms. Neat vinyl-terminated silicone fluids generally fall under 3910 00 00 90. The table also includes specified preparations and application-specific silicones for buyers ordering formulated material; those descriptions do not automatically cover the neat fluid. See the wider silicone guide.

The supplied tariff record gives a 6% base duty for these Chinese-origin goods and lists no anti-dumping or countervailing duty. Under 3910 00 00 90, named platinum-catalysed addition-curing liquid mixtures for textile, automotive and electrical applications have a 0% suspension with restrictive footnotes. The listed preparation and implant lines also show suspensions. Do not assume that vinyl termination alone qualifies: have the broker check the full description and exclusions.

The tariff attaches an import waste control. If material from China is waste subject to notification, shipment requires consent from the competent authorities of destination, dispatch and transit. Ask your customs broker to confirm the waste status and applicable procedure before dispatch. Confirm the commodity code using composition, physical form and intended use.

Specify vinyl content and viscosity together

Specify vinyl end groups, polymer identity, vinyl content and its reporting basis, viscosity at an agreed test temperature, volatile content, residual cyclic siloxanes and any additives. Distinguish neat fluid from silica-filled preparations and catalyst-containing mixtures. Agree the test methods, acceptance limits, storage conditions and shelf life in the purchase specification.

Trial the fluid in your actual formulation with your crosslinker and catalyst. Compare cure behaviour and the resulting material with an approved sample. A matching viscosity does not establish matching vinyl content or cure performance.

Polymers are exempt from UK REACH registration requirements, but check the registration position for relevant monomers and additives. Chemical classification is the supplier's responsibility, including importers. Obtain the composition information and safety data sheet needed for that review before ordering.

Worked duty example

Illustrative example, not a quote: Illustrative order: 5 tonnes of neat vinyl-terminated silicone fluid in sealed drums 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 maker's grade, vinyl end-group description and batch number against the approved specification and batch certificate.

Analysis: check viscosity, vinyl content, volatiles and agreed residual cyclics; compare an independently tested retained sample with the certificate.

Cure: check a sample in the agreed formulation for cure behaviour and the specified properties of the cured material.

Packing: check drum seals, leaks, contamination, production dates and batch labels on arrival; retain samples before using the lot.

What goes wrong

A supplier substitutes a fluid with similar viscosity but different vinyl content, or supplies a filled preparation instead of neat polymer. The customer's cure balance then changes. Contamination, excessive volatiles and inconsistent batches can also cause failed trials or finished-part defects.

Costing fails when a buyer assumes every addition-curing ingredient qualifies for a suspension. Obtain the complete formulation description for classification and agree batch acceptance checks before shipping. Use quality inspection planning to define sampling and release decisions.

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.