Microwave safe plastic- is it really safe?
UPdate Fall 2007

Does this conversation sound familiar?
“ Hey, don’t put that container in the microwave. It’s plastic. It could leach chemicals into the food.”
“ But its labeled microwave safe ­ it must be ok.”

What does microwave safe really mean? Does it mean safe for people, or safe for containers?

It means if you put a “microwave safe” plastic container into the microwave, it is not going to bubble and melt. It means no one handling the container will suffer a burn from melting plastic.

But after that, the debate starts.

Frederic vom Sall is a world expert on Bisphenol A (BPA). He has been studying the chemical for over a decade. "There is no such thing as safe microwaveable plastic," vom Saal says. "As you heat it, you degrade the chemical bond. You can't see this happening. You can't taste it, you can't smell it, but you are getting dosed at a higher and higher amount."

Studies exposing plastic to heat in a microwave caused higher levels of Bisphenol A to be released into food. The studies also found BPA was released when plastic containing BPA was exposed to heat from dishwashers and hot food. Some studies detected leaching even at room temperature. Heavily scratched or worn plastic releases even higher levels of chemicals.

BPA is classified as “inherently toxic” in Canada’s chemical management program. It is one of the first 200 chemicals up for review. Many scientists and environmentalists consider BPA one of the major chemical time bombs of our era, comparable to now banned chemicals such as DDT and PCBs.

"This chemical acts like the estrogen in birth control pills," says vom Saal. "As an adult man or woman, you are putting a sex hormone into your body that's going to alter your reproductive system. You decrease fertility. You cause sperm abnormalities." Evidence is showing that, unlike most chemicals, small exposures of BPA may be more harmful than larger ones. Because the effects of BPA are long-term and may not show up for years, it is a very difficult chemical to study. Dr. Helen Binns, a Chicago pediatrician and member of the American Academy of Pediatrics environmental health committee believes in precaution. She notes that while new products may make life easier, "We always need to approach their use with caution. Where clear, better alternatives exist, we need to choose the alternatives."

"We need more data,” Binns says. “The hard thing is, sometimes the data come too late. "The PCBs are out there. The DDT is out there.”

The watchdog organization, Environmental Defense Canada thinks that BPA is so dangerous that it has urged the federal government to ban BPA immediately rather than waiting for completion of the assessment. It's a logical step, says Rick Smith of Environmental Defense, considering there are alternatives to the chemical.

Health Canada’s website doesn’t reflect the conflicting evidence about the safety of microwaving plastic. Health Canada says only that “microwave safe” plastic is indeed safe. Although officially, government policy is to follow a precautionary approach, information from Health Canada does not reflect the state of the science.

Other types of plastic, such as plastic bags, yogourt or margarine containers, foam trays and plastic wraps are a definite no for microwave use. There is widespread agreement, from Health Canada, the US Environmental Protection Agency and other experts, that plastics which are not approved for microwave use may leach hazardous chemicals into foods.

BPA is a major ingredient in polycarbonate plastics, normally labeled with recycling number 7. While polypropylene and polyethylene plastics, marked with product codes 1, 2 and 5, appear safer, vom Saal says they may still contain BPA, because polycarbonate is often combined with other plastics, although it may not be listed on the label.

If you are going to microwave, it’s easy to find alternatives to plastic. Glass jars or covered dishes are excellent for food storage and can be used to reheat food in the microwave. Ordinary dishes can be used safely in the microwave too, as long as they are not plastic. As for cooking a chicken or roast, nothing tastes as good as oven roasting.

See also
Plastic linked to birth defects http://www.environmentalhealth.ca/spring03plastic.html