Sourcing microbiological peptones from China

Peptone duty and source-material checks

Read from the UK Trade Tariff on 5 November 2026, heading 3504 covers peptones, their derivatives and other specified protein substances. The relevant peptone lines carry 2% duty for goods from China. The supplied tariff record lists no anti-dumping or countervailing duty. Its suspension on 3504 00 90 99 is restricted to zein, rather than ordinary microbiological peptones.

The tariff attaches veterinary control and organic-product import control to the relevant lines. For animal-derived laboratory reagents made from milk products, the milk-product import requirements apply. Ask your customs broker to confirm the China-specific veterinary documents and entry arrangements for the actual peptone. For laboratory material carrying an organic claim, confirm whether the attached organic control applies and which documents are needed.

Casein hydrolysate belongs in 3504 00 90 10 only if it meets that line's composition conditions. Other peptones may fall within 3504 00 90 99. Give your broker the composition, source species, processing description and intended use to confirm the commodity code. See the wider protein heading guide for other protein substances.

Specify the digest and its culture performance

Specify casein, meat or soya origin, the animal species where relevant, and enzymatic or acid hydrolysis. Agree total nitrogen, amino nitrogen, moisture, ash, solubility, solution acidity and colour using named test methods and buyer-agreed acceptance criteria. Request a batch certificate of analysis and traceability to the manufacturing site.

Assess the peptone in your actual medium using your selected organisms and incubation conditions. Compare growth, recovery and any unwanted inhibition against a retained acceptable batch. Agree whether the supplied powder is sterile or requires your usual sterilisation process; do not treat a low microbial count as proof of sterility.

Worked duty example

Illustrative example, not a quote: Illustrative order: 20 kg of microbiological soya peptone under 3504 00 90 99, invoiced at £3,000 free on board, with £860 of freight and insurance to the UK. The customs value is £3,860. Duty at 2% is £77.20. Import VAT at 20% is charged on the customs value plus duty, £3,937.20, so it is £787.44. Import taxes total £864.64; a VAT-registered importer can usually reclaim the VAT, so the lasting cost is the £77.20 of duty. The import duty and VAT guide explains each step.

Inspection checklist

Identity: match the raw-material origin, digest type and batch reference to the purchase specification and certificate.

Packaging: check seals, liner integrity, moisture protection and signs of leakage or contamination.

Powder and solution: check caking, colour, dissolution and precipitate against the retained sample using the agreed preparation method.

Performance: compare growth and recovery in the intended medium before releasing the batch for routine use.

What goes wrong

A batch can meet its nitrogen assay yet give poor organism recovery because its peptide profile, salts or processing residues differ. Changing the raw material or hydrolysis process without requalification can change culture performance. Hold unfamiliar lots until the application comparison is complete.

Moisture ingress causes caking and makes sampling less representative. Animal-origin paperwork can also be mismatched to the actual species, manufacturing site or use. Resolve the import route before shipment rather than assuming that a laboratory label settles the veterinary control.

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.