Sourcing L-leucine from China

L-leucine classification and duty

Read from the UK Trade Tariff on 1 October 2026, heading 2922 covers oxygen-function amino-compounds. The supplied facts do not name L-leucine separately. Residual amino-acid code 2922 49 85 90 carries 0% duty for goods from China, with no anti-dumping or countervailing measure or suspension recorded. The table repeats this candidate code for different buying specifications; these are not separate tariff lines.

The UK Trade Tariff attaches Veterinary control and Export control - Waste to that line. Give your customs broker the manufacturing process and raw-material origin, and confirm whether the veterinary requirement applies to the actual China-origin shipment. Ask the broker to confirm the relevance of the waste measure if a return or disposal shipment is contemplated.

Confirm the commodity code using the substance identity, composition and intended presentation before ordering. Do not assume the same classification covers a blended supplement. For wider heading context, see the L-isoleucine guide.

Specify L-leucine identity and powder performance

Specify L-leucine rather than an unspecified leucine grade or an amino-acid blend. Agree identity and optical identity tests, assay basis, related amino acids, moisture, particle-size distribution and packing. Ask the factory to declare the production route, raw-material origin and any added processing aids.

For food use, agree contaminant and microbiological testing against your intended application. Sellers of food supplements are responsible for ensuring they are safe for consumption. A supplier's food-grade description should be supported by batch evidence, rather than treated as acceptance.

Before importing a substance into Great Britain, ask HSE to confirm whether UK REACH registration is required for your annual volume and intended use, and whether any exemption applies. Resolve the applicable position for your intended use before shipment. Agree the test scope through testing and certification.

Worked duty example

Illustrative example, not a quote: Illustrative order: 2,500 kg of L-leucine powder, assuming the residual amino-acid classification is confirmed under 2922 49 85 90, invoiced at £21,000 free on board, with £2,500 of freight and insurance to the UK. The customs value is £23,500. Duty at 0% is £0. Import VAT at 20% is charged on the customs value plus duty, £23,500, so it is £4,700. 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: check the shipped batch is L-leucine and that the identity and optical identity results match the agreed specification.

Analysis: compare batch assay, moisture, related amino acids and application-specific contaminant results with the purchase specification.

Powder: check particle size, visible contamination and lumps; trial the powder in your mixing or filling process.

Packing: check liners, seals, dampness and damaged containers; match batch labels to the certificate of analysis and delivery documents.

What goes wrong

A generic amino-acid certificate does not establish L-leucine identity. An assay result without its calculation basis can conceal a mismatch between the ordered specification and the supplied powder. Different particle sizes can also change handling and blending performance.

Treat torn liners, damp powder, unexplained lumps or mismatched batch records as reasons to hold the affected stock for investigation. Agree sampling and acceptance criteria before shipment, and assess the delivered batch rather than relying on a catalogue certificate.

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.