BPA Substitute Triggers Similar Endocrine-Disrupting Effect

"BPA-free" products might not be as safe as you think. Researchers at the Environmental Health Science and Research Bureau in Canada have found that a common substitute for bisphenol A (BPA) has similar endocrine-disrupting effects. The substitute - bisphenol S (BPS) - was found to induce adipogenesis (fat cell formation) in a manner similar to BPA.

BPA has been used for decades in manufacturing plastics and other products, but as of 2014, the chemical has been linked to health problems in nearly 100 studies. In response, BPA use has been restricted by regulations in some states and countries, particularly in products for babies and children. This has led many manufacturers to replace BPA with alternatives.

Bisphenol S (BPS) is now a common substitute for BPA, found in everything from canned food, baby bottles, thermal receipt papers, epoxy resins, and polycarbonate plastics. The chemical structure of BPS closely resembles BPA; in BPS, the dimethylmethylene (C(CH₃)₂) group linking the functional phenol groups is replaced with a sulfonyl (SO₂) group.

Considering its structural similarity, it's not surprising that BPS could have similar health effects as BPA. A different study by researchers at the University of Calgary found that zebrafish exposed to BPS in concentrations similar to those found in a nearby river exhibited increased neural cell growth and hyperactivity. And in a separate investigation at the University of Cincinnati, BPS was found to cause heart arrhythmia in rats.

When reviewing any scientific study, one of the most important tasks is determining the limitations of the study's methods or results. In the research on BPS's effects on fat cell formation, for example, only a limited number of subjects were used and most effects were statistically significant only at concentrations higher than regular human exposure.

It would seem, though, that the similarities and differences between BPA and BPS justify further investigation of BPS's effects on health. It might be that in searching for a substitute for BPA, industry has chosen an ingredient just as potentially hazardous as the original chemical.