People eating hot food out of melamine tableware have been found to have raised levels of the toxic chemical in their bodies.
The findings have raised fresh concerns over possible health risks associated with melamine, which is used to make housewares products from tableware and picnicware to kitchen tools, along with adhesives and industrial coatings.

In the new study of melamine tableware, researchers at Kaohsiung Medical University in Taiwan asked 12 men and women to eat soup out of either a ceramic bowl or a melamine bowl. Three weeks later the participants were asked to switch bowls.

Following the test it was found that those eating out of the ceramic bowls had 1.31 micrograms of the chemical in their urine, while those who had used the melamine bowls had 8.35 micrograms.

The amount of melamine leaching into food and drink from melamine tableware varied by brand. But, warned lead researcher Dr Chia-Fang Wu: "Melamine tableware may release large amounts of melamine when used to serve high-temperature foods."

He said that although the clinical significance of levels of urinary melamine concentration had not yet been established, "the consequences of long-term melamine exposure still should be of concern."

Studies have suggested that melamine can cause kidney failure and there is also a possible link to cancer. There have been cases in which it has been used as an additive to foods to simulate a higher protein content, the most notorious of which occurred in China in 2008. Some 300,000 people fell ill and six babies died after a milk product manufactured for infants was found to have been bulked up with melamine.

Two years ago, tests done on melamine tableware by Hong Kong's Center for Food Safety found that it was safe in normal use. The researchers said melamine did leach into the food but that the levels were well below those specified by the European Union.

However, they advised people not use to use broken or damaged melamine products and echoed Dr Chia-Fang Wu's warning about its use with hot foods. They recommended that melamine-ware should not be used to contain hot foods or to heat or cook foods in a microwave or conventional oven. It should also not be cleaned with abrasive detergents.