Sourcing diatomite insulating bricks from China
Bricks, blocks, tiles and other ceramic goods of siliceous fossil meals such as diatomite and kieselguhr, or similar siliceous earths, from China pay 0% UK duty under the single code 6901 00 00 00, with no anti-dumping duty. They are lightweight insulating bricks for kilns and furnaces, and buyers check density, thermal conductivity, maximum service temperature, strength and breakage.
0% duty
Read from the UK Trade Tariff on 29 October 2026, heading 6901 covers bricks, blocks, tiles and other ceramic goods of siliceous fossil meals (for example kieselguhr, tripolite or diatomite) or of similar siliceous earths. It is a single code carrying 0% on goods from China, with no anti-dumping measure. The waste import control on this code is answered by a not-waste declaration.
Dense refractory bricks are covered in our refractory bricks guide, and loose diatomite in our diatomite guide; confirm the commodity code.
| Goods | Commodity code | Duty | Anti-dumping duty on China |
|---|---|---|---|
| Bricks, blocks, tiles and other goods of siliceous fossil meals or earths | 6901 00 00 00 | 0% | None |
Specifying insulating bricks
Specify bulk density, thermal conductivity at stated temperatures, maximum service temperature, cold crushing strength, permanent linear change on heating, dimensions and tolerances, and crated packing. Ask for the technical data sheet and a safety data sheet, because cutting and machining can release crystalline silica dust.
Worked duty example
Illustrative example, not a quote: 5,000 diatomite insulating bricks under 6901 00 00 00, invoiced at £4,000 free on board, with £1,200 of freight and insurance to the UK. The customs value is £5,200. Duty at 0% is £0. Import VAT at 20% is charged on the customs value plus duty, £5,200, so it is £1,040. 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
Data: check density and dimensions on samples against the data sheet.
Breakage: check packing and count broken bricks on arrival.
Trial: fire a sample to the working temperature for a new supplier. See our quality inspection guide.
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What goes wrong
Insulating brick orders fail on density, dimensions and breakage. Density is higher than stated so insulation is worse, sizes vary, and fragile bricks break in loose packing.
Cambridge China Bridge sources refractories and kiln materials for UK kiln builders and potters from small lots; see small orders.
Frequently asked questions
What is the UK import duty on diatomite insulating bricks from China?
Read from the UK Trade Tariff on 29 October 2026, siliceous earth bricks under 6901 00 00 00 carried 0% from China.
Are dense refractory bricks in heading 6901?
No. Dense refractory bricks are heading 6902.
What matters most for insulating bricks?
Low density and thermal conductivity at the working temperature, and the maximum service temperature.
Is cutting these bricks hazardous?
Cutting can release crystalline silica dust; use dust controls and follow the safety data sheet.