A new study suggests exposure to bisphenol-A  (BPA) is actually much greater than previously thought, and its authors urge the federal government to act quickly to regulate the chemical that is in baby bottles, food-storage containers and many household products.

The peer-reviewed study, published Sept. 20 in the online NIH journal Environmental Health Perspectives, also says BPA exposure is likely coming from many sources–including some  still unknown.

Researchers at the University of Missouri Division of Biological Sciences, Veterinary Medical Diagnostic Lab and the department of Biomedical Sciences, working with scientists at the University of California-Davis and Washington State University, co-authored the study.

One of the researchers, Frederick vom Saal, professor of biological sciences at the University of Missouri, said in a news release that the study “provides convincing evidence” that BPA is dangerous and that “further evidence of human harm should not be required for regulatory action to reduce human exposure to BPA.”

Connecticut, Massachusetts, Washington, New York and Oregon now have limits on BPA, particularly in products used by children, but the California legislature recently rejected a BPA ban.  Similar legislation has been proposed in Congress, where it is a distinctly partisan issue.  The effort by Sen. Dianne Feinstein (D-CA) to add a BPA ban to the Food Safety Modernization Act has been met with dogged resistance from Republicans. 

Two years ago Canada announced it would be the first country to ban plastic bottles made with BPA and recently took the first step toward making good on that promise – placing BPA on a toxic-substance list under the Canadian Environmental Protection Act, a move that should be final by November.

But the controversy over BPA has raged on in the United States, with one side dismissing a multitude of studies as flawed and arguing that the chemical is not only safe but beneficial, for myriad uses such as can liners, thermal paper and dental sealants.  Immediately after this latest research was published, some critics questioned the researchers’ impartiality and charged that the study was just another scare tactic.

Environmentalists and others who want BPA banned contend the chemical is an endocrine disrupter that may be a factor in infertility, certain cancers and immune disorders.

Julia Taylor, lead author of the new study and associate research professor at the University of Missouri, said, “For years, BPA manufacturers have argued that BPA is safe and have denied the validity of more than 200 studies that showed adverse health affects due to exposure in very low doses of BPA.”  But “we know that BPA leaches out of products that contain it, and that it acts like estrogen in the body.”

The research led by Taylor used BPA-exposed mice and monkeys and compared the findings with prior published data for women.  The researchers discovered that women, female monkeys and female mice metabolize the chemical in similar ways and argue for the validity of animal studies in assessing how BPA affects humans.

The researchers say estimates vary widely of just how much people are exposed to BPA daily and they question the commonly held belief that most exposure comes from food-storage containers or other plastic products. 

Pat Hunt, professor in the Washington State University School of Molecular Biosciences and one of the study’s co-authors, said, “We’ve assumed we’re getting BPA from ingestion of contaminated food and beverages.  This indicates there must be a lot of other ways in which we’re exposed to this chemical and we’re probably exposed to much higher levels than we have assumed.”

The U.S. Environmental Protection Agency, which last year rated the potential effects of low doses of BPA as “negligible” or “of some concern,” says daily exposure of up to 50 micrograms of BPA per kilogram of body weight is safe.  But the University of Missouri research suggests people are exposed to at least eight times that amount.

With nearly 8 billion pounds manufactured each year,  BPA is one of the highest-volume chemicals ever produced.  The Centers for Disease Control and Prevention estimate that the compound is present in more than 90 percent of the U.S. population.

Consumer skepticism about BPA has been building and so far has been more influential in limiting it than regulation.  Wal-Mart, Whole Foods and Sears are among the retailers who have promised to stop selling items like baby bottles and sippy cups made with BPA and customer complaints have prompted some manufacturers to switch to BPA-free materials.

The authors of the new study say that BPA is likely to be in so many things that the government should require the chemical industry to identify all products that contain it.


  • Jim

    Perhaps this news account is skewed, but it’s hard to read it and not come way feeling these “researchers” had an agenda. This looks like enviro-political activism very thinly disguised as science.

  • DontAnnoyMe

    You don’t have any idea what science is if you think that. NIEHS is way ahead of FDA and EPA in terms of doing studies that are accurate and meaningful. Unfortunately, they have no control over legislation.

  • Don

    What this and other press reports don’t say is that the blood level found in this study was about 2 nanogram/mL (or 2 ppb) which is similar to that found in the general human population. An alternative interpretation is that monkeys and humans are very effective at metabolizing BPA, so even though the monkeys were purposely fed doses of BPA 8 times higher than the EPA limit (why only high doses?), the blood levels remained LOW. The authors have completely missed (or dismissed) this interpretation. Vom Saal and Hunt have authored many papers which, coincidentally, always find dire consequences for even part per trillion exposure to BPA. What they don’t reveal is that much of their work on BPA effects in mice, for example, has not been reproducible by other researchers and has been criticized by leading toxicologists (both U.S. and Europe). The quote attributed to Hunt about being exposed to BPA from many other sources besides food and plastics is pure speculation and not based on any hard evidence.

  • doug

    Don wrote “always find dire consequences for even parts per trillion…”
    That language is the subtle language of ridicule. It suggests that it is silly to think that parts per trillion are laughably small and inconsequential.
    I have reviewed Dr. Von Saal’s paper see no reason to agree with Don assumption.
    Dr. Vom Saal demonstrated that human cells respond to trillions of a part of chemicals. They do so by increasing their ability to detect environmental chemical signals at that level. Yes it is counter intuitive but the data is there; cellular response is not linear but extraordinarily small doses of BPA result in the increase of BPA detection abilities within cells.
    Dr. Von Saal’s work flatly gives the lie to that the idea that the effectiveness of a poison is always in the size of the dose.
    I don’t know why cells have evolved to function in this manner. The possibilities are endless.
    My point is not to confirm the dangers of BPA but to point out that Dr. Von Saal’s (and others) have made a valuable contribution to science with this breakthrough in the way molecular biologists think about cellular behavior.
    Of course this advance in understanding was not possible even ten years ago as the technology was not available to detect signal as small a one in a trillion.
    Again my point is that Don’s reasoning relies on the idea that a part per trillion is too small to have an effect, and he is demonstrably wrong about that.