Sourcing trimethylchlorosilane from China
Trimethylchlorosilane from China pays 6% UK duty on the named line for purity by weight of 98% or more, with no listed suspension or trade remedy. GB supply requires correct chemical labelling and packaging; check UK REACH registration before ordering. Cambridge China Bridge sources trimethylchlorosilane.
6% duty on the named trimethylchlorosilane line
Read from the UK Trade Tariff on 1 October 2026, heading 2931 covers other organo-inorganic compounds. Its named chlorotrimethylsilane line, 2931 90 00 40, covers CAS identity 75-77-4 with purity by weight of 98% or more. The table repeats this single tariff line for different purchasing formats; packaging descriptions do not represent separate tariff lines.
Goods from China on this line carry 6% duty, with no listed anti-dumping or countervailing duty and no suspension. The tariff attaches export controls on dangerous chemicals and waste. Confirm their relevance to your China import with your customs broker. If the substance is on the GB prior informed consent list, annual quantity reporting to HSE applies. If a shipment is waste subject to notification controls, the exporter must seek consent from the dispatch country's competent authority.
Confirm the commodity code using the substance identity, composition and batch purity. Do not assume this named line covers lower-purity material or formulated mixtures. For the wider product family, see silane coupling agents.
| Goods | Commodity code | Duty | Anti-dumping or countervailing duty on China |
|---|---|---|---|
| Trimethylchlorosilane, purity by weight 98% or more | 2931 90 00 40 | 6% | None |
Specify trimethylchlorosilane purity and packaging
Use the substance identity 75-77-4 in the enquiry and purchase order. Agree purity by weight, the assay method, the impurity profile and acceptance criteria for acidity and appearance. Ask for a batch certificate of analysis and discuss a suitable moisture assessment with the testing laboratory.
Specify container material, closure and seal compatibility, pack size and the intended dispensing method. Ask the supplier to explain how filling and sampling exclude moisture. Agree transport classification and packaging with the carrier before booking, and trial a sample in your intended process.
For a first import into Great Britain, check whether UK REACH registration is required. Review annual tonnage and registration or valid transitional coverage before ordering. Chemicals supplied on the GB market must be correctly labelled and packaged. A safety data sheet is required when a hazardous chemical is supplied for use at work.
Worked duty example
Illustrative example, not a quote: Illustrative small-business batch in sealed drums under 2931 90 00 40, invoiced at £4,000 free on board, with £2,500 of freight and insurance to the UK. The customs value is £6,500. Duty at 6% is £390. Import VAT at 20% is charged on the customs value plus duty, £6,890, so it is £1,378. Import taxes total £1,768; a VAT-registered importer can usually reclaim the VAT, so the lasting cost is the £390 of duty. The import duty and VAT guide explains each step.
Inspection checklist
Identity: match the substance name and 75-77-4 across the order, batch certificate, container labels and safety data sheet.
Assay: check batch-specific purity and impurity results against the agreed specification, using an independent laboratory where appropriate.
Containers: inspect unopened packs for damaged closures, broken seals, leakage and corrosion; arrange sampling through the agreed handling procedure.
Traceability: reconcile batch identifiers and delivered quantities with the packing list, and keep inspection findings linked to the batch.
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What goes wrong
A generic purity certificate can conceal an unsuitable impurity profile or fail to identify the delivered batch. Treat mismatched certificates, unexplained acidity or failed process trials as reasons to hold the batch pending investigation. A passing assay alone does not establish suitability for your reaction or analytical method.
Packing failures include loose closures, damaged seals and unsuitable dispensing arrangements. Check these before accepting the delivery. Resolve differences between the supplied labels, safety data sheet and actual composition before releasing the material for use or onward supply.
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.
Frequently asked questions
What is the UK import duty on trimethylchlorosilane from China?
The supplied tariff record gives 6% for 2931 90 00 40, covering purity by weight of 98% or more, with no listed suspension, anti-dumping duty or countervailing duty.
Which commodity code covers trimethylchlorosilane?
The named line is 2931 90 00 40 for substance identity 75-77-4 with purity by weight of 98% or more. Confirm classification separately for lower-purity material or mixtures.
Do I need UK REACH registration?
Check whether your first import requires registration. Review annual tonnage and your registration or valid transitional coverage before ordering; the factory's batch certificate does not establish that coverage.
What should I check when trimethylchlorosilane arrives?
Check batch identity, certificate of analysis, assay and impurities, container seals and leakage. Use an agreed sampling procedure and investigate discrepancies before releasing the batch.