Sourcing Colloidal Silica from China

Colloidal silica duty and suspension limits

Read from the UK Trade Tariff on 1 October 2026, heading 2811 covers other inorganic acids and other inorganic oxygen compounds of non-metals. Aqueous colloidal silica belongs within the silicon dioxide family; check 2811 22 00 90 against the actual formulation. The table shows application grades using the same commodity line, rather than separate tariff subdivisions.

The supplied tariff record gives 4% duty for goods from China, with no anti-dumping or countervailing measure recorded on this line. Its 0% suspensions concern silica filler granules of at least 97% silicon dioxide and specified chromatography powders under authorised use. The separate amorphous powder line also has a suspension. These descriptions do not cover liquid colloidal silica. Compare the wider silica family in our precipitated silica guide.

The tariff attaches import and export waste controls. For waste from China entering England under notification controls, the exporter must apply to the dispatch country's competent authority for consent and follow its procedures. Ask your customs broker to confirm the attached controls for your consignment, including any proposed waste return. Confirm the commodity code using composition, physical form and additives.

Specify the sol, stabiliser and process

Specify silica solids by mass, particle size distribution, acidity or alkalinity, viscosity, density and the stabilising system. Identify sodium, ammonium or other stabilisers and any surface treatment. Agree limits for trace metals, coarse particles and microbial contamination where relevant to your process. State whether the material is a plain aqueous sol or contains functional additives.

Agree test methods, sampling conditions, storage conditions and a batch certificate of analysis. Trial the proposed grade in your casting slurry, polishing process, coating or refractory mix. A matching solids content alone does not establish equivalent performance.

For Great Britain, ask HSE to confirm UK REACH registration coverage or an applicable exemption before importing, including the relevant annual threshold. Substances in mixtures also fall within registration scope. Check the formulation's classification and ask HSE to confirm applicable GB classification, labelling and packaging duties and safety data sheet language requirements. Provide a safety data sheet where legally required, including hazardous chemicals supplied for workplace use.

Worked duty example

Illustrative example, not a quote: Illustrative order: 25 tonnes of aqueous colloidal silica in drums under 2811 22 00 90, invoiced at £15,000 free on board, with £2,000 of freight and insurance to the UK. The customs value is £17,000. Duty at 4% is £680. Import VAT at 20% is charged on the customs value plus duty, £17,680, so it is £3,536. Import taxes total £4,216; a VAT-registered importer can usually reclaim the VAT, so the lasting cost is the £680 of duty. The import duty and VAT guide explains each step.

Inspection checklist

Batch identity: match drum markings, formulation and certificate of analysis; retain a representative sample from each supplied batch.

Liquid condition: check for gel, sediment, skin, contamination and coarse particles; compare particle distribution and viscosity with the approved sample.

Composition: verify solids content, acidity or alkalinity, stabiliser and relevant impurities against agreed methods and acceptance limits.

Packing and documents: check seals, leaks, container compatibility and net mass; match the safety data sheet and applicable hazard labels to the formulation.

What goes wrong

A supplier substitutes a sol with the same solids content but a different particle distribution or stabiliser. Casting slurry behaviour changes, polishing leaves scratches, or a coating becomes unstable. Dilution, contamination, unsuitable storage or freezing can also leave sediment or gel. Agree storage protection and repeat the process trial when the formulation changes.

A generic certificate or safety data sheet can describe a different grade from the liquid delivered. Compare batch results with the approved sample through quality inspection, and hold a suspect batch pending investigation. Do not accept a suspension claim based solely on the words silicon dioxide.

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.