There has definitely been a lot of talk about the dangers of BPA. BPA is short for Bisphenol A, which is a chemical used to produce polycarbonate plastics (like plastic water bottles). This type of plastic is clear and tough. Things that commonly contain BPA include water bottles, the coatings on the inside of many food and beverage containers (cans, especially), and the paper used for sales receipts.
Recently, a few reports came out about the negative effects of BPA on the body. One study, mentioned in this article in the New York Times, showed that drinking soy milk from a container with a BPA-containing liner compared to drinking soy milk from a glass bottle led to an increase in blood pressure (about 5 mmHg) within 2 hours. BPA has long been considered to be an endocrine disruptor, and can supposedly bind to estrogen receptors that are important in blood vessel repair and blood pressure control. A number of years ago, the Environmental Working Group (EWG) conducted a study on the amount of BPA that has leached in foods from cans. According to EWG, “of all foods tested [from cans], chicken soup, infant formula, and ravioli had BPA levels of highest concern”. Although considered safe by the American Chemistry Council, BPA is no longer used in the manufacturing of baby bottles and children’s cups. Now it is common to see plastics labeled as “BPA-free”.
Are plastics that are BPA-free safer? And what does it mean to be BPA-free?
Oftentimes, BPA is replaced by Bisphenol S (BPS). In a recent study in PNAS, embryonic zebrafish were exposed to low doses of BPA and BPS (additional reporting on the study here). Exposure to either resulted in decreases in hypothalamic neurogenesis (i.e. exposure to BPA or BPS affected brain development). The decrease was greater in BPS than BPA. This suggests that BPA-free plastics containing BPS may actually be less safe than conventional BPA-containing plastics. From a common sense point of view, a business/plastics producer does not need to replace a compound with something “better” or “safer”, just one that satisfies the consumer at the moment. If a consumer wants something BPA-free, then a business only needs to give them something that doesn’t contain BPA.
So what can one do? Purchase glass or stainless steel water bottles, and avoid eating from cans and drinking from plastic bottles of any kind. Additionally, one should probably avoid microwaving plastics and switch to glass (such as Pyrex) or other alternatives. But it may be difficult to avoid BPA (and similar chemicals) altogether.
[Update: new study shows that BPA, and even more so estradiol (synthetic estrogen used in birth control), disrupts sperm production in mice.]