Sourcing diatomaceous earth filter media from China

Duty on activated diatomaceous earth filter media

Read from the UK Trade Tariff on 2 October 2026, heading 3802 includes activated natural mineral products. The relevant diatomaceous earth lines carry 0% duty for goods from China, with no anti-dumping or countervailing measure recorded. Unactivated natural diatomite belongs under heading 2512. For the wider heading, see activated carbon and filter aids.

Code 3802 90 00 19 also records a 0.00 % autonomous suspension for non-acid-washed soda-flux-calcined diatomaceous earth used as a filter aid in pharmaceutical or biochemical manufacture. Its footnote excludes mixtures, preparations and products containing different components. The relevant lines attach import and export waste controls. Confirm their application with your customs broker. For imports under notification controls into England, shipment can begin only after consent from the Environment Agency and the other competent authorities involved.

Confirm activation, soda-flux treatment, acid washing and intended use before selecting the commodity code. The table repeats a code where different purchasing grades share a tariff line. Import VAT is normally 20%; the calculation includes the customs value, applicable duties and relevant incidental expenses. See UK import duty and VAT.

Specify the filter cake, not just the powder

Specify activated diatomaceous earth, the calcination route, whether soda flux is used and whether the product is acid washed. Agree particle-size distribution, permeability, wet cake density, moisture and filtrate clarity using named test methods. Describe the liquid, filter equipment and operating conditions so the factory can propose a grade for a process trial.

Ask for the exact grade's crystalline silica composition, safety data sheet and batch certificate of analysis. Before importing a substance you have not previously imported, consider whether UK REACH registration is required. A product that is dangerous for supply must come with a safety data sheet. That sheet is not a risk assessment.

For pharmaceutical or biochemical filtration, agree extractables testing and customer acceptance criteria before ordering. Check acid-washing records and trial the approved sample with the intended process liquid. Use factory verification to check the production route and batch traceability.

Worked duty example

Illustrative example, not a quote: Illustrative order: 20 tonnes of soda-flux-calcined diatomaceous earth filter media under 3802 90 00 19, invoiced at £30,000 free on board, with £2,500 of freight and insurance to the UK. The customs value is £32,500. Duty at 0% is £0. Import VAT at 20% is charged on the customs value plus duty, £32,500, so it is £6,500. 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

Identity: match bag labels, grade, batch and certificate to the approved activated material and its acid-washing status.

Performance: compare particle size, permeability and filtrate clarity with the approved sample using the agreed test methods.

Purity: check the agreed moisture, crystalline silica composition and extractables results against the batch certificate.

Packaging: inspect seals, liners, damp patches and powder leakage; retain an identified arrival sample before releasing the lot.

What goes wrong

A substitute grade can look similar but build a less permeable cake, shorten the filtration run or leave a cloudy filtrate. Wet or compacted powder can form lumps and disperse unevenly. Compare incoming material with the approved sample in the actual process rather than accepting colour or a generic certificate as proof of performance.

Acid-washed and untreated grades can be confused on paperwork, leaving the buyer without the extractables evidence agreed for the process. Recovered or spent material also needs a separate waste-control check. Where its status or the attached tariff control is unclear, confirm the requirement with your customs broker before shipment.

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.