Sourcing caustic calcined magnesia from China

Duty and waste controls

Read from the UK Trade Tariff on 8 November 2026, caustic calcined magnesia within heading 2519 falls under other magnesia, code 2519 90 90 00, at 0% duty for goods from China. No anti-dumping or countervailing duty or suspension is recorded in the supplied tariff data. The table also shows feedstock and comparison grades; these are distinct from caustic calcined magnesia.

The UK Trade Tariff attaches import and export waste controls. Ask your customs broker to confirm their application to the proposed Chinese shipment before dispatch. For waste imported into England under notification controls, the exporter must apply to the competent authority in the dispatch country for consent. For a Chinese dispatch, that application therefore starts with the competent authority in China.

Confirm the production route, composition and intended use through finding your commodity code. The magnesia and magnesite guide covers the wider heading. Confirm your UK REACH registration position with HSE based on annual imports of the substance. Suppliers must ensure chemicals are correctly labelled and packaged before placing them on the Great Britain market.

Specify reactivity as well as chemistry

Caustic calcined magnesia is a reactive grade used in agriculture, feed and water treatment. Specify magnesium oxide content, lime, silica, iron and other relevant impurities, particle size, loss on ignition and bulk density. State the intended application so the factory quotes the appropriate grade.

Agree a citric acid activity test method and acceptance criteria before approving the sample. Compare production batches using that same method, rather than accepting an unexplained activity figure. For feed use, confirm applicable limits for undesirable substances such as heavy metals with the relevant feed authority; request a batch analysis against the intended specification.

Worked duty example

Illustrative example, not a quote: 25 tonnes of caustic calcined magnesia in lined bulk bags, illustrative only under 2519 90 90 00, invoiced at £12,000 free on board, with £2,500 of freight and insurance to the UK. The customs value is £14,500. Duty at 0% is £0. Import VAT at 20% is charged on the customs value plus duty, £14,500, so it is £2,900. 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

Chemistry: compare the batch analysis with the agreed magnesium oxide and impurity specification; retain a sample for independent checks.

Reactivity: test the delivered batch using the agreed activity method and compare it with the approved sample.

Powder condition: check sieve results, loss on ignition and bulk density against the specification; examine arriving material for hard lumps and caking.

Packing: inspect bag liners, seals and batch identification before loading and on arrival; record torn bags, damp patches and contamination.

What goes wrong

A batch can meet its magnesium oxide specification yet react too slowly because it was over-burned. Approving chemistry alone misses this failure. Require both chemistry and activity results, and trial the approved sample in your process before committing to the production grade.

Moisture and carbon dioxide uptake change the material during storage; hydration can cause swelling and caking. Specify lined, sealed bags and dry storage. Keep batch identities separate on arrival so a damp or slow-reacting lot can be investigated without mixing it into accepted stock.

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.