Melamine is a type of thermosetting plastic with a strong, hard surface. This plastic is relatively lightweight, and resists structural damage from acids and alkaline materials, as well as staining. These features make melamine a popular material for dinnerware, cooking utensils, mixing bowls and other cooking-related products. Like many plastics, melamine should not be microwaved, due to the risk of damage to the material and the potential risk for toxins leaking into food.
Ingesting high levels of melamine can cause kidney failure, while low levels on a regular basis may contribute to respiratory problems or cancer. Melamine is considered an irritant when it comes into contact with the skin or eyes. However, melamine-formaldehyde tableware is considered safe, according to the United States Food and Drug Administration because the melamine doesn't migrate into most foods. Melamine toxicity is primarily a danger when food is accidentally or deliberately contaminated with this plastic via industrial accident or in an attempt to increase the apparent protein level of the food.
Melamine is safe to use with cool and warm foods. However, according to the Hong Kong Special Administrative Region Centre for Food Safety, heating melamine to around 240 degrees Fahrenheit can cause toxic chemicals, including melamine and formaldehyde, to migrate out of melamine-ware and into food. Migration levels are relatively low in most cases, but long-term exposure could have some health effects.
Acid and Melamine
According to the US Food and Drug Administration, melamine's chemical migration problem becomes more significant in the presence of acidic foods. Heating melamine-ware containing acidic food, such as tomato sauce, orange juice or vinegar, to temperatures higher than 160 degrees Fahrenheit causes increased chemical migration and potential health effects. Leaving acidic materials in melamine containers for a long period of time also could cause problems.
Microwaving non-microwave-safe plastics, including melamine, can damage the plastic material, as well as causing potential health risks. Microwaved plastic may warp, melt or bubble. Melamine softens in heat, making it a poor choice in the microwave and as a stirring utensil for hot foods. Keep melamine tableware cool, and use it only for serving and storage.