Risk Evaluation Institute Issues Warning on Melamine

Health & Wellness on 05.23.11
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Do your kids have melamine plates or cups, maybe with their favorite cartoon characters pictured in a brightly colored motif? Or those handy divided compartments that keep the tomato sauce from oozing onto their brownie? Melamine, or Melmac, dishes have become popular souveniers, as well as inexpensive and durable replacements for the decorated porcelain or china pieces your mom probably never took out of the cupboard.

The Melamine Scandals

You may remember that melamine caused the Chinese infant milk formula scandal. The nitrogen-rich building block for thermoset plastic mimics protein in tests to determine the nutritional quality of the milk substitute. The criminals behind those scandals were certainly threatening child welfare by selling a product incapable of meeting a growing child's need for the building blocks of life. But they may not have thought they were selling poison: melamine has long been considered relatively non-hazardous, and the extent of the illnesses caused by the melamine surprised even knowledgable toxicologists. And you probably did not throw out the melamine at that time, because the official word indicated that the dishware remains safe to use.

In a sense, the toxicologists were not wrong. Melamine passes quickly out of our systems -- a good thing because it does not stick around and build up over time. And large quantities can be consumed without harm. Deeper analysis after the illnesses related to the infant formula scandal, and earlier pet feed contamination cases, showed that the problem lies in the interaction between melamine and other chemicals in the body. Certainly in the presence of a common contaminant, the melamine does not simply pass through. Instead, it forms crystals, which settle into the renal tubes leading to kidney damage and even renal failure.

Safe Levels of Melamine

On the heels of the real-life evidence of serious kidney damage caused by melamine, agencies went back to the drawing board. The World Health Organization (WHO) issued a tolerable daily intake (TDI) of 0.2 mg/kg body weight, down from 0.5 mg/kg. The European Food Safety Authority (EFSA) followed suit, reducing the melamine tolerable daily intake to 0.2 mg/kg as well. The US FDA retained its TDI of 0.63 mg/kg but issued a melamine safety and risk assessment which declined to set a "safe" level for infant formula, but declared that up to 2.5 parts per million (ppm) of melamine in foods other than infant formula can be considered safe.

According to a new study by the Bundesinstitut für Risikobewertung (BfR, or German Federal Institute for Risk Assessment), melamine cookware and crockery are not suitable for microwaving, cooking, or exposure to high temperatures.The studies by the BfR showed that up to 4.6 mg/kg (ppm) of melamine can migrate in tests simulating the use of melamine cups or bowls for hot liquids (70°C or 158°F). In tests simulating leaving a melamine stirrer in a cookpot, levels up to 14.4 ppm of melamine were found in the test foods. Although the BfR assesses the 4.6 ppm levels for hot food contact as safe, these values exceed the 2.5 ppm level established by the US FDA. The FDA study applied a safety factor of ten, though, so the BfR is probably still correct: the melamine migrating from the use of melamine dishware for hot foods is not a cause for concern.

The Formaldehyde Factor

Unfortunately, the breakdown of melamine resin chains to release the melamine compound has a side effect. Melamine resin manufacturing uses formaldehyde as a linking agent to combine the melamine molecules into long chains. When the polymer chain breaks down to release melamine, it also releases formaldehyde.

The BfR found that leaving melamine cookware in contact with cooking foods for longer periods can cause formaldehyde to be released at levels above those the BfR considers safe. Formaldehyde has a range of known hazards -- including being a suspected carcinogen, toxic by all routes of exposure, and causing allergies. Formaldehyde is also volatile, meaning only part of it stays in the food, while over half is released into the air we breath. The BfR calculates that if half of the formaldehyde released enters the air, it will reach almost three times the level BfR considers safe to breath in a kitchen that is 3 x 4 meters, with a 2.5 meter ceiling height (approximately 10 x 13 feet, with an 8-foot ceiling).

Safe Use of Melamine Dishes and Cookware

So does this mean all the melamine in your house should go straight to the trash, or onto an heirloom-display wall mount? Not necessarily. Melamine is still a pretty handy, indestructible dishware; and it is safer than many other plastic options. If you can follow the recommendations below, you can still use your melamine safely:

  1. Do throw away all melamine utensils intended for cooking, such as spoons, spatulas, etc. If these utensils still have their glossy sheen -- that is, their surfaces do not have a matte, sand-blasted appearance due to melamine that has already migrated out -- you can still use these items in cold applications like tossing salads or serving cake.
  2. Don't microwave melamine. You may already avoid putting melamine in the microwave because the dishes get hot, or even blister or crack. But even if a short zap does not produce blisters, hot spots develop that will accelerate the breakdown of the melamine.
  3. Don't wash melamine items in high temperature dishwashers. A cycle at 60°C (140°F) should be sufficient to sterilize your dishes and remain within the temperatures which the BfR found to be safe.
  4. Do share carefree meals with your kids enjoying their favorite melamine dishware. Let food cool to a safe temperature for eating before putting hot foods onto your child's plate -- which will keep them safe from both chemicals and burns.

The BfR is a scientific body that works under the auspices of the Federal Ministry of Food, Agriculture and Consumer Protection (BMELV). It advises the German Government and State Governments, conducting research on topics related to their mission.
 

Photo: GranniesKitchen/CC

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