Food-use clay: why it needs its own checks
Terracotta and earthenware are fired at lower temperatures than stoneware, so the body stays porous. That porosity is the point of a clay water pot, which cools water by letting a little seep through and evaporate, and of clay cookware, which is soaked before use. It is also the source of most problems: soft, underfired pieces, mould in damp cartons and glazes that were never fully fused.
Much food-use clay is made by small family potters, thrown on a wheel or pressed in moulds and fired in open or wood-fired kilns, where temperature varies across the load. An exporter collects pieces from many potters. Two pots of the same design can have very different hardness, and glazes on clay cookware may come from local suppliers with little control over lead.
Gorakhpur district is the Uttar Pradesh ODOP district for terracotta, described on the ODOP site as GI-tagged, but its listed products are mainly figures, vases, lamps and planters rather than food ware. No verified cluster stands out for food-use clay. TradeStat shows exports of US$12.27 million for clay tableware and kitchenware (HS 69120040) in FY2025-26 (provisional). For garden pots, see terracotta and glazed planters, which covers frost and drainage.
What we check on terracotta and earthenware
| Check | How it is checked | What fails |
|---|---|---|
| Firing | Colour against reference pieces; surface scratched with a fingernail; pieces held free and tapped | Pale, chalky, soft pieces; dull note from a hidden crack |
| Seepage and leaks | Water pots, bottles and cooking pots filled and left to stand on dry paper | Drips, wet base, wet patches spreading faster than the agreed sample |
| Glaze on food surfaces | Glaze colour and type compared with the tested sample; surface checked for soft, matt or unfused areas | Untested glaze; glaze that scratches easily, a sign of underfiring and leach risk |
| Mould and odour | Inside of pots and cartons checked and smelled; moisture of cartons | Mould spots, musty smell, damp cartons |
| Salt bloom | Surface checked for white crystalline deposits | Efflorescence on food or visible faces |
| Lids and fit | Lid placed and turned on each sampled pot; spouts and taps on water pots fitted and run | Rocking lid, leaking tap seal |
| Base and stability | Pieces set on a flat table; round-bottom pots on their stands | Rocking or tipping when filled |
| Marking and instructions | Décor pieces checked for the not-for-food mark; use and care leaflet (soaking, no sudden heat) checked | Missing permanent mark, missing instructions |
Common terracotta and earthenware defects and how they are classed
| Defect | Typical cause | Class |
|---|---|---|
| Food-use glaze without a passing lead and cadmium test | Local glaze, untested colour, different potter | Critical |
| Décor piece that looks usable for food with no not-for-food mark (US, Canada) | Mark left off or only on the carton | Critical |
| Mould inside pots | Packed damp, long storage | Major |
| Hidden crack | Uneven drying or firing | Major |
| Seepage beyond the sample | Underfiring, thin walls | Major |
| Uneven colour, small surface chips | Kiln position, handling | Minor |
Your defect list decides the final class.
Rules for clay that touches food
- US. FDA judges ceramic ware against lead and cadmium action levels under CPG 545.450 and 545.400. Under 21 CFR 109.16, decorative ceramics that look usable for food need a conspicuous stick-on label and a permanent statement on the base, or a hole through the food surface. FDA has warned specifically about traditional pottery with lead glazes. See lead and cadmium in ceramics.
- EU. Directive 84/500/EEC places cooking ware in its strictest category (1.5 mg/L lead and 0.1 mg/L cadmium), along with storage vessels over 3 litres, which takes in large water pots. A declaration of compliance is needed. See EU food contact and LFGB.
- Canada. SOR/2016-175 sets leach limits and allows decorative pieces to be exempt only with a hole or mounting hook, or a permanent bilingual warning in capital letters at least 3 mm high.
- California. Lead and cadmium are on the Proposition 65 list.
Unglazed clay can still release metals from the body, so buyers often test unglazed cookware too. Tests are done by an accredited lab on samples we pull and seal.
Packing and your purchase order
Porous clay takes up moisture from the air and from wet packing. Pieces should be dry before packing, packed with dry paper or straw that is itself free of mould, and kept off wet floors. Desiccant in cartons helps on long voyages. Wood wool or straw as packing material may need plant-health treatment in some markets. Round pots need fitted inserts so they cannot roll and knock.
- Clay type, glazed or unglazed, and which surfaces are glazed.
- Glaze supplier and colour, the leach test standard and market, and which potter or unit makes each item.
- Seepage and hardness limits agreed against a sample.
- Marking: "Not for food use" where needed, in the form each market requires; use and care instructions.
- Moisture control in packing and the packing material.
For harder, high-fired ware, see stoneware dinnerware.
Sources
- ODOP Uttar Pradesh: Gorakhpur terracotta
- 21 CFR 109.16, Ornamental and decorative ceramicware (eCFR)
- FDA guidance: Safety of imported traditional pottery and use of the term “lead free”
- Directive 84/500/EEC, consolidated with Directive 2005/31/EC (EUR-Lex)
- Canada: Glazed Ceramics and Glassware Regulations (SOR/2016-175)
- Department of Commerce: TradeStat commodity-wise exports (FY2025-26, provisional)