A new study is lending more support to the idea that BPA-free products aren't necessarily safe products. Bisphenol S, or BPS, an alternative to BPA, appears to cause problems in the brain growth of animal embryos, researchers say. After studying zebra fish, whose brain development is seen as similar to humans', experts at the University of Calgary found that the changes caused by both BPA and BPS seemed to result in hyperactivity, the Washington Post reports. The results were a surprise given the dose involved, the study's lead author tells CBC: Zebra fish embryos were exposed to levels of BPA and BPS found in Alberta rivers. "We used a dose that is lower than what developing babies have naturally and we found that brain development is perturbed (in the fish)," the author notes.
When compared to BPS, BPA prompts similar, though weaker, brain-cell growth surges, and researchers say that all similar materials may be dangerous. "A lot of the alternative chemicals (to BPA) have not been adequately tested because they don't have to be," says the author. "A compound is considered safe (by the Food and Drug Administration) until proven otherwise." The effects of BPS were seen on male hormones, which could help explain why autism is so much more common in boys than in girls, though at this point that's just speculation, the researcher adds. An industry group calls the experiment "limited" and says it doesn't offer conclusions on human health. But the researchers say that pregnant women should avoid plastics and receipts at stores, which have also been shown to contain BPA. (Read more bisphenol A stories.)