BPA-free plastics may not be safer than regular plastics after all, a new study finds

Sept 16: Consumers turning to plastics made with alternatives to BPA in the hope that they’re safer won’t like what they’re about to hear.

A new study, published in the journal Current Biology, concluded that common alternatives to BPA caused harmful effects in mice, notably in their reproductive cells. The findings add to the mounting body of evidence that these alternatives carry their own health risks. As Science noted, if further research on animals and humans continues to support these findings, it could derail efforts to reassure the many consumers already nervous about the plastics in their food and drink containers that there are safe options to choose from.

The issue has been one of major concern in recent years, in part because of the work of Patricia Hunt, the Washington State University geneticist who led the team behind the new research. She first helped draw attention to the possible perils of BPA—bisphenol A in its long form—after stumbling on them by accident.

The industrial chemical has been used for decades to make the plastics that food is packaged in and the resins used to line items such as cans. In 1998, she was doing a study using the eggs of mice when she found that an unusually high number of them had defects. She figured out that a temporary worker in the lab had used a harsh floor cleaner, instead of the usual mild detergent, to clean out the mice’s cages and bottles, damaging the plastic and causing BPA to leach out.

The new study tested the effects of BPA and common alternatives, such as BPS (bisphenol S), BPF, and BPAF on female and male mice. It found that the chemicals disrupted the way genetic information was passed down during meiosis, the division of cells necessary to produce egg and sperm cells in sexually reproducing animals, and suggests that the problem is with “bisphenols as a class.”

The new study arose from circumstances similar to the one that prompted Hunt’s first look into BPA. She had recently discovered that the normal washing of her new, BPA-free cages, made of polysulfone, was degrading to form BPA-like compounds and causing similar issues. It was “a strange déjà vu experience,” Hunt told Science. It prompted the deeper look into BPA alternatives.

The past several years have seen growing worried about BPA, over fears that the practically ubiquitous chemical affects hormones, reducing sperm counts and causing other issues. But what danger it really poses is still unclear. Groups such as the Natural Resources Defense Council have asked the US Food and Drug Administration (FDA) to ban it. The FDA refused but did bar its use in baby bottles and sippy cups. A recent government study found it not much of a threat.

Still, many people look for alternatives. For them, the study by Hunt and the other authors has a warning: “Although ‘BPA free’ is a valuable marketing tool, and most consumers interpret this label as an indication of a safer product, our findings add to growing evidence from studies in C. elegans, zebrafish, mice, and rats, as well as human in vitro studies that replacement bisphenols have the potential to induce adverse effects similar to those reported for BPA.”