BPA Alternatives: Why Mixing Them Matters

Bisphenol A, a common plastic ingredient, has been pulled out of many products because it can disturb hormones. Scientists now see that the chemicals used to replace BPA are very similar in shape and action. These substitutes often show stronger effects than BPA itself. When researchers looked at water samples from across Europe, they found a mix of BPA and its replacements. They tested these mixtures in lab cells to see how toxic they were, whether they could mimic estrogen, and if they harmed mitochondria. The results matched a simple rule: the total effect is roughly the sum of each part’s contribution. Even chemicals that only partially activate estrogen receptors added up to noticeable hormone‑like activity. For another receptor, called the aryl hydrocarbon receptor, most mix components didn’t trigger it on their own. Instead they acted as general poisons, and the receptor’s activation appeared only when cells were already under stress.To make sense of these data, scientists created a tool called “BPA‑equivalent concentration” or BPA‑EQ. This lets them express the potency of any bisphenol mixture in terms of how much BPA would be needed to produce the same effect. Using this method, a typical European water sample containing five common BPA replacements had overall toxicity 24 times higher than BPA alone, and estrogenic power 12 times higher. The study also showed that one particular substitute, BPPH, dominated the toxic effect, while BPZ and BPAF were the biggest estrogenic contributors. These findings suggest that simply swapping one bisphenol for another is risky; the chemicals act together and can be more dangerous than expected. Overall, the research urges regulators to evaluate bisphenol replacements as whole mixtures rather than isolated substances. A change in one chemical group on the bisphenol core can lead to a “regrettable substitution” that harms ecosystems more than it helps.