Enamel-coated iron or steel cookware is generally easier to maintain than cast iron because it does not rust. Although enamel forms a very hard cooking surface, it can chip when used incorrectly or when it becomes old. Chipped enamel cookware poses a health risk because enamel chips can end up in food.
Cookware manufacturers generally recommend discarding chipped enamel cookware. Once enamel starts to chip, it usually continues to chip. Flakes of it can detach from the cookware and end up in food. Besides being unappetizing, the sharp flakes can be unsafe. They may cause painful cuts in the mouth and throat.
While modern enamel cookware made and sold in the U.S. does not contain dangerous levels of lead, cadmium or other heavy metals, older enamel cookware and enamel cookware from countries outside the U.S. may contain unhealthy metals. If the origin of an enamel piece is unknown, it is especially important to avoid using it after it chips. Cadmium is especially common in red, yellow and orange enamel.
Enamel Chip Repair
Most companies will not repair chipped enamel cookware for liability reasons. Home repair by the owner also is difficult because the enamel glaze commonly found in stores is not usually high enough in quality to use for cooking at high temperatures. Some people recommend "seasoning" exposed cast iron beneath chipped enamel by rubbing it with oil. This technique will prevent the cast iron from rusting. However, it is not a completely safe solution since the enamel might continue to chip.
Many cookware companies will replace chipped enamel pots if the user did not cause the chips through improper care. If improper use did cause the enamel to chip, many companies will offer a generous discount on a replacement pot.