October 23rd, 2008
Bisphenol A Found To Have No Reproductive And Developmental Effects At Low Doses
Bisphenol A, a chemical predominantly used in the production of polycarbonate plastic and epoxy resins, has recently been the subject of public and scientific scrutiny regarding potential reproductive and developmental effects. People are exposed to minute levels of bisphenol A, mostly through the ingestion of food in contact with such products as water bottles, baby bottles, and food containers made of polycarbonate plastic and food and beverage cans coated with epoxy resins.
Recently, an expert panel led by scientists at Gradient Corporation in Cambridge, Massachusetts completed an extensive scientific review of the reproductive and developmental effects of bisphenol A. Based on its review of all the relevant scientific literature, the panel found no consistent evidence of reproductive or developmental effects of bisphenol A at typical human exposure levels. The review considered all studies published through July 2008 that examined reproductive and developmental toxicity in animals at low bisphenol A doses. No studies were excluded based on study design or source of funding.
According to Dr. Lorenz Rhomberg, the senior author of the review, "The hypothesis that the low levels of bisphenol A to which people are exposed could disrupt reproduction and development is not supported by coherent, consistent, or compelling evidence."
Government agencies from the US, the European Union, and Japan have also concluded that bisphenol A is not harmful at the low amounts to which people are normally exposed. Most recently, in a draft report, the US Food and Drug Administration concluded that the trace amounts of bisphenol A that leach out of food containers are not a threat to infants or adults. These conclusions are partly based on the results of several large studies of the effects of bisphenol A in rats and mice that were dosed with bisphenol A continuously over multiple generations. In these studies, animals were exposed during all life stages from conception through adulthood and reproduction. Bisphenol A had no effects on these animals at doses including those similar to human exposure levels.
There is agreement among these panels and government agencies that effects of bisphenol A only occur at exposures approximately 100,000 times higher than a person would typically ingest. In addition, people are better at excreting ingested bisphenol A than are rats and mice. In people, bisphenol A in the body is converted to a metabolite that does not have estrogen-like activity, and is rapidly eliminated in the urine. Despite the media attention suggesting otherwise, to date, the overwhelming majority of government and academic scientific panels have concluded that bisphenol A is safe at the very low amounts that people normally ingest.
The panel included Gradient scientists Drs. Lorenz Rhomberg and Julie Goodman, as well as Dr. Glenn Sipes of the University of Arizona and former president of the Society of Toxicology, Dr. Ernest E. McConnell, formerly of the National Toxicology Program, and Dr. Raphael Witorsch of the Virginia Commonwealth University School of Medicine. The full report has been published in the peer-reviewed journal Critical Reviews in Toxicology and is available at http://dx.doi.org/10.1080/10408440802157839. A summary of the report is also provided in the most recent issue of the Gradient Risk Sciences Bulletin, available here or upon request.