Chemical used in plastics is toxic, dangerous, Mizzou researcher says
By BILL SMITH 04/29/2003

A controversial chemical used to make common hard plastic items such as drinking glasses and food-storage containers is a serious public health hazard and should be banned, a researcher at the University of Missouri at Columbia insists.

The researcher, Fred vom Saal, was expected to take his plea to a meeting of scientists and environmental experts at the Toxicology and Risk Assessment Conference near Dayton, Ohio, this week. The conference is sponsored by several governmental agencies, including the U.S. Environmental Protection Agency. The agencies study the potential dangers of chemicals.

The chemical, bisphenol A, or BPA, is an artificial estrogen used to create the plastic polycarbonate. It is also used in resins to line some metal cans and in the manufacture of some dental sealants.

It is commonly found in hard plastic drinking glasses, some microwavable food containers and plastic baby bottles.

More about bisphenol A

A new study, released this month by geneticists at Case Western Reserve University in Cleveland, showed that even low doses of BPA in adult female mice caused chromosomal changes that could lead to birth defects.

As a result, many researchers believe that BPA also presents a hazard to humans, although no direct link has been proven.

"The danger is apparent to almost anyone," said Wade Welshons, a veterinary medicine researcher who has worked with vom Saal in BPA research for 13 years.

He said BPA-related products generate $10 billion a year for the plastics industry.

Welshons said the Case Western research is the first to show that BPA is dangerous not only during certain crucial periods of pregnancy, but "all the time, particularly in women."

Welshons said earlier research by himself and vom Saal showed that the offspring of female mice that ingested small amounts of BPA showed a variety of abnormalities including enlarged prostrates in males, heavier body weight in both males and females and earlier onset of puberty in females.

Until the Case Western study, though, Welshons said researchers believed that exposure could be avoided simply by staying away from BPA during pregnancy. The Case Western study found that BPA can lie inside the mother like a time bomb ready to detonate once she becomes pregnant, Welshons said.

The plastics industry continues to play down the dangers of BPA. A Web site sponsored by the Bisphenol A Industry Group of the American Plastics Council says that other studies "clearly support the safety of BPA and provide strong reassurance that there is no basis for human health concerns from exposure to environmentally relevant doses of BPA."

The industry also notes that the use of polycarbonate plastic and epoxy resins for food contact applications is recognized as safe by the Food and Drug Administration, as well as other regulatory authorities around the world.

Steven Hentges, executive director of the Polycarbonate Business Unit of the American Plastics Council, said Tuesday that an industry-financed study completed last year on four generations of laboratory rats showed no birth defects resulting from lower dosages of BPA. Only when extremely high dosages were administered, enough to poison the animals, did researchers see health effects. Hentges called the study the most comprehensive ever done on BPA and animal reproduction.

Vom Saal was en route to Ohio Tuesday for his talk today and could not be reached.

Plastics containing BPA are usually readily identifiable by a triangular recycling label with the number "7" in the center.