Sourcing sulphites and thiosulphates from China
Sulphites and thiosulphates from China, such as sodium sulphite, other sulphites and sodium thiosulphate used in water treatment, photography, textiles, pulp and food processing, pay 4% UK duty on all three lines of heading 2832, with no anti-dumping duty. Buyers check grade and assay, iron and heavy metals, GB CLP labels, and for food use the additive grade.
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4% duty
Read from the UK Trade Tariff on 17 November 2026, heading 2832 covers sulphites and thiosulphates, with lines for sodium sulphites, other sulphites and thiosulphates. All three lines carried 4% on goods from China, with no anti-dumping measure. The tariff also attaches a waste import control, answered by a not-waste declaration.
Sulphates are covered in our sulphates and alums guide; metabisulphites (disulphites) are classified with sulphites or elsewhere depending on the compound, so confirm the commodity code from the CAS number.
| Goods | Commodity code | Duty | Anti-dumping duty on China |
|---|---|---|---|
| Sodium sulphites | 2832 10 00 00 | 4% | None |
| Other sulphites | 2832 20 00 00 | 4% | None |
| Thiosulphates | 2832 30 00 00 | 4% | None |
Grades and labelling
Specify the compound and CAS number, grade (technical, photographic, food or pharmaceutical), assay, iron, heavy metals and insolubles, and packing. Sulphites used as food additives must be a food-grade product meeting the additive specification, and foods containing sulphites above the allergen threshold must declare them, so food users need the grade certificate.
Many sulphites and thiosulphates carry GB CLP classifications and release sulphur dioxide with acids, so ask for the GB-format safety data sheet and labels.
Worked duty example
Illustrative example, not a quote: 10 tonnes of sodium thiosulphate for water treatment under 2832 30 00 00, invoiced at £6,000 free on board, with £1,500 of freight and insurance to the UK. The customs value is £7,500. Duty at 4% is £300. Import VAT at 20% is charged on the customs value plus duty, £7,800, so it is £1,560. Import taxes total £1,860; a VAT-registered importer can usually reclaim the VAT, so the lasting cost is the £300 of duty. The import duty and VAT guide explains each step.
Inspection checklist
Analysis: check assay and impurities against the certificate.
Packing: check lined bags or drums and moisture protection, since sulphites oxidise in damp air.
Documents: check the safety data sheet and grade certificate. See our quality inspection guide.
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What goes wrong
Sulphite orders fail on assay, oxidation and grade. Assay is low because the product oxidised in damp packing, technical grade arrives for a food use, and labels miss GB requirements.
Cambridge China Bridge sources industrial chemicals for UK manufacturers with documents and transport agreed before shipment. See factory verification.
Frequently asked questions
What is the UK import duty on sodium thiosulphate from China?
Read from the UK Trade Tariff on 17 November 2026, thiosulphates under 2832 30 00 00 carried 4% from China.
Can technical-grade sodium sulphite be used in food?
No. Food use needs a food-grade additive product with a grade certificate.
Why do sulphites lose strength in storage?
They oxidise in damp air; keep packing sealed and dry.
Are sulphates in heading 2832?
No. Sulphates are heading 2833.