Plastic. It's cheap. It's durable. It's colorful, and if you have kids you've probably got at least one collection of brightly-colored, serving plates in your kitchen. So convenient—just plop their favorite lunch on one of those cute, flowered-shape yellow dishes and zap it in the microwave.

Convenient (and cute), but is melamine safe? The jury is still out, but new research found that serving hot foods, such as soup, in melamine tableware could increase exposure to the chemical.

Melamine is an organic nitrogenous compound (chemical) used in the production of plastics, dyes, fertilizers, concrete and fabrics. Countertops, dry erase boards, glues, housewares and flame-retardants can also contain melamine. In the United States, it is approved for use in the manufacturing of some cooking utensils, plates, plastic products, paper, and industrial coatings. In other countries, melamine is used in fertilizer.

How Harmful Is Melamine? 

  • Melamine can mimic protein in certain foods. It's illegal use by manufacturers in China led to a series of scandals in 2008 when approximately 300,000 children were sickened and at least six babies died after ingesting infant formula containing toxic levels of the substance. (Adding melamine made the formula appear more nutritious and concealed the fact that the milk had been diluted with water in order to increase production.)

  • In large enough quantities melamine can cause kidney damage. It combines with cyanuric acid, which exists as an impurity in the chemical and can cause kidney stones to form in the body.

  • Other toxic effects from melamine include: chronic kidney inflammation and bladder cancer-both of which have been studied in animals.

What the Research Says About Melamine

According to the Journal of the American Society of Nephrology, the toxicity of melamine taken orally in humans has never been studied. However, the U.S. Food and Drug Administration (FDA) conducted extensive testing to determine if melamine from plastic tableware can leach into foods.

By and large, the FDA found that melamine does not migrate from tableware into most foods. But, under exaggerated conditions (food held in tableware at 160°F for two hours) very small amounts of the chemical did find their way into acidic foods.

As a result, the FDA recommends against heating foods and drinks on melamine-based dinnerware in microwave ovens. "Only ceramic or other cookware which specifies that the cookware is microwave-safe should be used," reads the FDA statement, which goes on to say melamine-based tableware is safe for food serving purposes.

In today's global society where much of the manufacturing process is outsourced experts urge consumers to exercise extra vigilance. Susan Fisher, PhD, RD, a professor of nutrition, health and human performance at Meredith College in Raleigh, NC worries many do not use products responsibly. "The FDA has made clear recommendations but how many of us remember to check for safety before microwaving?" she asks. "We have to be extra mindful especially with regard to vulnerable populations like children and older adults since their bodies are more susceptible to the negative impact of potentially toxic substances."

Since plastic is ubiquitous Fisher advises consumers to be aware of the dangers in plastic products bought at garage sales and containers meant for food storage purposes only, too. "Heat changes the stability of the polymers in the plastic and much of this stuff was never intended to withstand heat," Fisher explains.

The safest course is too keep all plastic out of the microwave. "It's not that inconvenient to empty food from plastic container into a safer glass one before heating but many of us are just too lazy—or forgetful—to do it."

Susan Fisher, PhD, RD, reviewed this article.