Sulphates and alums from China
Sulphates from China pay 4% UK duty, except copper sulphate at 2%, with no anti-dumping duty. Suspensions give 0% to manganese sulphate monohydrate, lithium sulphate over 99% pure, zirconium sulphate and aluminium alums to 31 December 2028. The use decides the rules: food additive, fungicide, bath salt or water treatment. Cambridge China Bridge sources industrial and food-grade sulphates.
Magnesium, aluminium, copper, zinc, iron and sodium sulphates, alums and persulphates from China: 2% or 4% UK duty, 0% suspensions, grades and tests.
4%, copper at 2%, and four 0% suspensions
Read from the UK Trade Tariff on 26 September 2026, sulphates of heading 2833 carried 4% duty on goods from China and copper sulphates 2%, with no anti-dumping measure or registration. Suspensions to 31 December 2028 give 0% to manganese sulphate monohydrate, and, from 18 July 2025, to lithium sulphate of more than 99% purity, zirconium sulphate and aluminium alums; none applies to mixtures or preparations containing them. Aluminium sulphate has a 0% line only for pharmaceutical substances listed in the reliefs reference document.
Ammonium sulphate and potassium sulphate are fertilisers of chapter 31, not heading 2833, and natural barium sulphate (barytes) is a mineral of chapter 25. Ferrous sulphate falls under the 'other' line. Confirm the commodity code from the salt, the hydrate and the purity on the certificate of analysis.
| Goods | Commodity code | Duty | Anti-dumping duty on China |
|---|---|---|---|
| Disodium sulphate | 2833 11 00 00 | 4% | None |
| Magnesium sulphate (Epsom salt, kieserite) | 2833 21 00 00 | 4% | None |
| Aluminium sulphate | 2833 22 00 00 | 4%; 0% for listed pharmaceutical substances | None |
| Copper sulphate | 2833 25 00 80 | 2% | None |
| Zinc sulphate | 2833 29 20 00 | 4% | None |
| Manganese sulphate monohydrate | 2833 29 80 20 | 4%; 0% to 31 Dec 2028 | None |
| Other sulphates, including ferrous sulphate | 2833 29 80 80 | 4%; lithium and zirconium sulphates 0% to 31 Dec 2028 | None |
| Alums | 2833 30 00 00 | 4%; aluminium alums 0% to 31 Dec 2028 | None |
| Peroxosulphates (persulphates) | 2833 40 00 00 | 4% | None |
The end use sets the rules
The same salt is regulated differently by use. Magnesium, sodium and aluminium sulphates used as food additives must meet the purity criteria for their E numbers, which are now kept on the [FSA food additive authorisations register](https://data.food.gov.uk/regulated-products/food_authorisations); Epsom salt packed as bath salts is a cosmetic product and needs a UK responsible person and a safety assessment; copper sulphate sold for use as a fungicide is a plant protection product that needs GB authorisation, which importing the chemical does not give; and aluminium sulphate for drinking water treatment is specified to BS EN 878.
An importer of more than one tonne a year of each substance should check UK REACH registration; see our UK REACH guide. Copper and zinc sulphates are classified as hazardous to the aquatic environment, and persulphates are oxidisers, so read the safety data sheet for the UN number and class before booking freight.
Worked duty example
Take a hypothetical order of 24 tonnes of magnesium sulphate heptahydrate in 25 kg bags, entered under 2833 21 00 00: £4,800 free on board plus £1,500 of freight and insurance gives a customs value of £6,300. The 4% duty on magnesium sulphate comes to £252, and import VAT is 20% of £6,552, which is £1,310.40. If you are VAT-registered you normally reclaim the £1,310.40, leaving £252 as the real cost at the border. Manganese sulphate monohydrate would pay nothing under its suspension, so the exact salt and hydrate decide the rate. Step by step: UK import duty and VAT.
What goes wrong
Sulphate lots fail on assay, hydrate and impurities. Heptahydrate and monohydrate are confused, so the buyer pays for water; the assay is quoted on a different basis from the certificate; aluminium sulphate carries more iron than the non-ferric grade allows; food or feed grades exceed limits for lead or arsenic; insolubles block dosing equipment; and bags cake solid after humid storage or tear in handling.
Test each lot for assay by titration or ICP against the specification, loss on drying or ignition to confirm the hydrate, insoluble matter, iron and heavy metals for food, feed and water treatment grades, and particle size where it is dosed or blended. Check bag weights, liners and pallet wrapping, and match lot numbers to the certificate of analysis before loading.
Cambridge China Bridge sources sulphates and alums for water treatment, agriculture, food, cosmetics and industrial users, and can qualify a Chinese producer as a second source beside a current supplier. See our second-supplier service.
Frequently asked questions
What is the UK import duty on magnesium sulphate from China?
Read from the UK Trade Tariff on 26 September 2026, magnesium sulphate carried 4% from China, with no anti-dumping duty.
Is manganese sulphate duty free?
Manganese sulphate monohydrate has a 0% suspension to 31 December 2028; it does not apply to mixtures containing it.
Can I sell imported copper sulphate as a garden fungicide?
Only as an authorised plant protection product; importing the chemical does not give GB authorisation for that use.
How do I check I am not paying for water in Epsom salt?
Specify heptahydrate or monohydrate, then test loss on drying and assay against the certificate of analysis.