Hazards in the Household #2: Plastics

Something else that scares me is a warm plastic water bottle that has baked all day in a summer-heated car-oven. You may have also heard from ominous emails, Care 2 Make a Difference  and HealthyChild.org that certain plastics (especially when heated) can put you and your family at risk for cancer.

I found the Harvard Medical School Family Health Guide to be very informative. When plastic is heated, potentially dangerous chemicals used in plastic manufacturing called plasticizers can leak out into food. The more thin and flimsy these are (i.e., cellophane wrap), the more plasticizers they contain. Because they are soluble in fats and oils, they especially leach into foods that contain a lot of fat. 

The HMS Guide describes FDA’s “Microwave – Safe” approval process:

“For microwave approval, the agency estimates the ratio of plastic surface area to food, how long the container is likely to be in the microwave, how often a person is likely to eat from the container, and how hot the food can be expected to get during microwaving. The scientists then measure the chemicals that leach out and the extent to which they migrate to different kinds of foods. The maximum allowable amount is 100–1,000 times less per pound of body weight than the amount shown to harm laboratory animals over a lifetime of use. Only containers that pass this test can display a microwave-safe icon, the words “microwave safe,” or words to the effect that they’re approved for use in microwave ovens.”

Here are some more great HMS pointers:

• Most takeout containers, water bottles, and plastic tubs or jars made to hold margarine, yogurt, whipped topping, and foods such as cream cheese, mayonnaise, and mustard are not microwave-safe.
• Microwavable takeout dinner trays are formulated for one-time use only and will say so on the package.
• Don’t microwave plastic storage bags or plastic bags from the grocery store.
• Before microwaving food, be sure to vent the container: Leave the lid ajar, or lift the edge of the cover.
•  Don’t allow plastic wrap to touch food during microwaving because it may melt. Wax paper, kitchen parchment paper, or white paper towels are alternatives.
• If you’re concerned about plastic wraps or containers in the microwave, transfer food to glass or ceramic containers labeled for microwave oven use.

Polycarbonate Plastics (i.e. Nalgene bottles)

There is an entire organization and website dedicated to BPA research and public information. It states: “Researchers from government agencies, academia, and industry worldwide have studied the potential for bisphenol A (BPA) to migrate from polycarbonate products into foods and beverages. These studies consistently show that the potential migration of BPA into food is extremely low, generally less than 5 parts per billion under conditions typical for uses of polycarbonate products. At this level, a consumer would have to ingest more than 1,300 pounds of food and beverages in contact with polycarbonate every day for an entire lifetime to exceed the safe level of BPA set by the U.S. Environmental Protection Agency. Consequently, human exposure to BPA from polycarbonate plastics is minimal and poses no known health risk.”

The Nalgene website includes further information if you are curious. 

PETE / PET (chasing arrows # 1; common for water bottles)

This review of recent findings suggest that endocrine disruptors (estrogen-like compounds suspected to trigger cancer growth) may leach into water and food contained by PET plastic bottles. Its conclusion is inconclusive … the jury is still out on this one. The hot Ozarka in my car? Still scary. I’ll pour it out for my plants. 

Plastics and the Microwave

The Plastics board produces this informative website and states: “There are many different types of plastics. The best bet on plastic packaging is if it is labeled “Microwave Safe”, then it will not leach unsafe chemicals into your food when microwaved or heated. Although it might be helpful to know a little about different plastics, PET plastic is one that can be either appropriate or inappropriate for the microwave depending on how it was manufactured. Plastic is not heated at all by microwaves, but rather by the hot food it comes in contact with. As long as a plastic cover or wrapping is not touching the food being heated, your food will be safe.” 

It also looks like the creepy Johns Hopkins email about dioxins in plastic containers is baloney. Here’s an excerpt from the FAQs: 

“I got an e-mail from Johns Hopkins alleging that microwaving food in plastic containers releases dioxin. Is this true?
No. This is an e-mail hoax that has been circulating the Internet for years. Dioxins are a group of compounds that can be produced by combustion at very high temperatures. The vast majority of plastics used in food wraps and packaging do not contain the chemical constituents needed to form dioxins. And dioxins form at very high temperatures, typically above 700 degrees Fahrenheit — much higher than the temperatures that would be generated by microwave cooking. You also may hear claims that using plastic containers in the freezer can “release” dioxins — which is also untrue. According to the FDA, which regulates food packaging, “With regard to dioxins, we have seen no evidence that plastic containers or films contain dioxins and know of no reason why they would.”
The e-mail and its alleged ties to Johns Hopkins University or Walter Reed Army Medical Center (depending on which version you receive) are part of the hoax, and both organizations have publicly disavowed the claims.”

A final quick update on foodborne carcinogens I found…to get more facts on overcooked meat and potential carcinogens, read the Addendum at the end of the post “Red Meat and Cancer: Not Guilty”.

I probably won't heat any plastics unless they're labeled "Microwave Safe." What do you Think?