A recent, peer-reviewed study published in the journal Food Additives and Contaminants: Part A investigated the effects of microwave heating on melamine formaldehyde tableware. The research team from the Kasetsart University, Thailand, described that the overall migration limit set by the European Union (10 mg dm-2) was exceeded after 25 heating cycles of 1 minute when 3% (w/v) acetic acid was used as food simulant. Mainly low molecular weight methylol melamine derivatives were identified as migrants, while formaldehyde was only found at low levels or was not detectable. The scientists conclude that microwave heating initiates other chemical reactions than conventional heating, leading to the high migration of melamine derivatives. Melamine is commonly used in reusable, unbreakable kitchenware, e.g. plates, cups and chopsticks.
Food Packaging Forum report on Melamine.
Poovarodom, N. et al. (2014) “Effects of microwave heating on the migration of substances from melamine formaldehyde tableware.” Food Additives and Contaminants: Part A. (online August 18, 2014)