In recent years, packaging manufacturers have moved away from Bisphenol A (BPA), the hardening agent that was once found in nearly all plastic bottles and containers.
A 2010 report from the Food and Drug Administration (FDA) raised concerns about BPA exposure, especially to pregnant women, children, and infants. Despite the fact that the FDA says low levels of human exposure to BPA are safe, manufacturers have begun to look for alternatives.
One alternative is Bisphenol S (BPS), and that's the agent used in many containers labeled as “BPA-Free.” However, researchers at UCLA have now raised concerns about the safety of the replacement.
Their study, reported in the medical journal Endocrinology, links BPS to early puberty and a rise in breast and prostate cancers.
Not necessarily safer
“Our study shows that making plastic products with BPA alternatives does not necessarily leave them safer,” senior author Nancy Wayne, a reproductive endocrinologist and a professor of physiology at UCLA, said in a release.
Wayne and her team used zebrafish for their study. It found that exposure to low levels of BPA and BPS—equivalent to the traces found in polluted river waters -- altered the animals’ physiology at the embryonic stage almost immediately, sometimes in as little as 25 hours.
As a result, eggs hatched earlier than normal. Embryos also developed much faster when either of the chemicals was present.
“Exposure to low levels of BPA had a significant impact on the embryos’ development of brain cells that control reproduction, and the genes that control reproduction later in life,” said Wayne. “We saw many of these same effects with BPS found in BPA-free products. BPS is not harmless.”
Wayne calls it the aquatic version of the canary in the coal mine.
BPA became an issue in the marketplace when it was shown to leach into food, particularly under heat, from the lining of cans and from consumer products such as water bottles, baby bottles, food-storage containers, and plastic tableware. It prompted Walmart to stop selling children's products containing BPA in 2008.
In 2012 the American Chemical Society (ACS) reported that people were also being exposed to BPS from the thermal paper used in cash register receipts. ACS noted at the time that BPS is closely related to BPA, with some of the same estrogen-mimicking effects, and “unanswered questions exist about whether it is safer.”