Experts debate plastic toxicity effects

by Kenneth Todd Ruiz
Assistant Editor

While using plastic cookware in microwave ovens has become common, concerns persist over potential harmful effects.

Most alarming is a claim that heating certain foods in plastic is a recipe for trouble, exposing consumers to dioxins and other harmful carcinogens.

According to the U.S. Environmental Protection Agency, dioxins are highly toxic chemicals formed as by-products from the manufacture, molding or burning of organic chemicals and plastics containing chlorine. Once they are absorbed into the body, these toxins stick around, wreaking havoc.

The World Health Organization reports that dioxins are powerful hormone disruptors that can damage male and female reproductive systems.

Only a few parts per trillion can result in cancer, reduced immunity, nervous system disorders, miscarriages or birth deformities.

Although dioxins are a serious health threat, the microwave-dioxin connection has been inadequately researched. Most experts, however, are dismissing such claims as little more than hot air.

"We have no evidence that plastic wrap or containers contain dioxins and know of no reason why they would," said Food and Drug Administration spokesman Ed Machuga.

A widely circulated e-mail message is responsible for heating these fears. Dr. Edward Fujimoto, director of the Center for Health Promotion at Castle Medical Center in Kailua, Hawaii, warns about the dioxin health risk.

Fujimoto, who is not a medical physician, was unavailable for comment.

According to Machuga, few studies have been conducted into the relationship between microwave ovens, plastics and dioxins. He acknowledged a more real, if less explosive concern.

"It is true that chemicals used to make plastics can leach into food," Machuga said. "But as part of the process approving product use, the FDA considers the amount of a substance expected to migrate into food and the toxicological concerns about the particular chemical."

Diethylhexyl adipate, or DEHA, is used to make plastic malleable and soft. Studies have shown that microwaving food ­ especially oils and animal fats - with plastic products results in DEHA leaking into the food.

"The level of plasticizer migration into food is very low, and below the level of toxicity," said Stephen Hentges, a spokesman for the American Plastics Council.

The FDA recommends that consumers only use products they have rated as microwave safe.

Restaurant carryout containers and other unmarked plastic items should not be heated in the microwave.

The FDA also warns against using foam trays and plastic wraps, which are not heat stable at high temperatures, as melting or warping may cause harmful chemicals to migrate into food.

One-time use packaging such as prepackaged microwaveable meals should never be reused, the FDA said.

"We suggest you don't use plastic wrap that's not microwaveable," said FDA spokeswoman Sandra King. "If you are uncertain, use wax paper or paper towels."

One such product is the ubiquitous Reynolds Saran Wrap.

Reynolds spokesman David Witt said that while their product is safe for use, it should not be placed in direct contact with food during microwave heating.

"Reynolds always meets or exceeds protective guidelines as established by regulatory agencies," Witt said. "We recommend turning back one edge of the plastic wrap to vent steam."

While heating plastics in microwave ovens may get a bad rap, there are legitimate concerns that can be allayed by taking basic precautions and following product usage instructions.

Caught in the crossfire of conflicting opinions and research, consumers might opt to dodge the plastic bullet entirely with two time-tested favorites: glass and ceramic.