You have just purchased or been given a beautiful set of melamine dinnerware. The product literature that comes with the dinnerware says melamine dishware does not break or stain easily and is considered dishwasher-safe. Also, the price is very reasonable. But you have heard, and have become worried, there may be some problems with melamine dinnerware the product literature does not mention.
What Is Melamine?
Melamine is an "organic" industrial compound. It is a nitrogen-rich heterocyclic triazine that is produced from one of three basic starting materials: urea, dicyandiamide or hydrogen cyanide. Because melamine is rich in nitrogen, it can be used to increase the apparent level of protein in certain foods, especially dairy and wheat products.
When melamine is combined, using heat and pressure, with formaldehyde and urea, a polymer known as melamine resin is created. This resin, once all the water it contains is released under pressure, becomes thermoset plastic, which can then be moulded and pressed into shapes, including dinnerware.
Melamine and Thermoset Plastic
Melamine resin is a versatile material with a highly stable structure that can be moulded into floor tiles, dry-erase whiteboard, fire-retardant fabrics and dishware. The resin is also called thermoset plastic because the "plastic" or shape of the material is fixed and unchanging after it has been moulded into shape, unless it is exposed to excessive heat.
Production Problems with Melamine Resin
Several toxic chemicals are used in the production of melamine resin, namely formaldehyde and urea. Under the pressure used to create the resin, melamine releases water which must be completely removed. If it is not, it makes the thermoset plastic unstable. This instability can cause the melamine resin to decompose back into its original elements, some of which are toxic.
What Breaks Down Melamine Resin?
Besides an improper manufacturing process, the thermoset plastic in melamine resin, while normally stable, can be at risk of breaking down into its toxic elements (including formaldehyde and urea) when exposed to high temperatures, such as the oven or the microwave.
This possibility of toxic breakdown means you should never put your melamine dishware into your oven or reheat food on it in your microwave.
Melamine Pet Dishware
Melamine dishware manufactured for pets was under scrutiny by veterinary scientists in 2007 because of pet deaths. They were trying to determine if the dishes were causing some hundreds of pet deaths from renal failure due to pet food contamination from using melamine dishes. However, it was found that melamine was also present in the wheat gluten commonly added to many commercial pet foods. This made it impossible to state with accuracy that use of the melamine bowls alone caused the pet deaths.
One conclusion reached was the possible combination of melamine in commercial pet food served on melamine dishware might contribute to what is called "synergistic poisoning"--poisoning that is the result of several sources of toxin in the environment.
Synergistic Melamine Poisoning
As a consumer, you could be at risk from synergistic melamine poisoning if you are consuming bread grown with a melamine-based fertiliser that has had a melamine additive to increase the apparent level of protein, served with milk that also had melamine added, on dishware made from melamine resin. The risk exists in combining sources of melamine. One element alone is probably safe; added elements may contribute to synergistic poisoning.
Recycling Melamine Dinnerware
Care must be taken when recycling melamine resin dishware. Since it is a thermoset plastic, dishware made from melamine resin, when broken down, reverts to formaldehyde and urea, which are toxic. This makes melamine resin an environmentally unfriendly material.