It's not exactly a secret that many plastic products have an additive called "bisphenol A," or "BPA," for short. NPR has covered the chemical substance many times, including here, here, and here.
Among other things, BPA helps make clear, hard plastic — the kind we associate with food storage containers and water bottles — and also lines the inside of many metal cans to prevent an aluminum taste from leaching into food or drink. The catch: Some studies suggest BPA could also disrupt our reproductive systems by changing sperm quality and increasing the risk of reproductive cancers like prostate and breast cancer.
Despite the coverage of BPA, when a reader wrote to the column and asked whether frozen dinner trays, rotisserie chicken containers, and other common items contained BPA, I was stumped. The reason? Manufacturers are not required to disclose whether their products contain BPA.
With limited information about what exactly goes into specific products, how should we view the materials in our kitchen? I reached out to academic scientists and the U.S. Food and Drug Administration for answers.
The root of scientists' concern about BPA in containers is that the chemical can leach out of packaging and into food. This happens when plastic deteriorates and releases its chemical contents, according to Nancy Wayne, a reproductive neuroendocrinologist at UCLA. Acidic foods, like tomato sauce, can break down plastic. Plastic also breaks down when heated; manufacturers may heat metal cans lined with BPA to sterilize them, and consumers frequently put plastic containers of food in the microwave. Once released, BPA can contaminate food and enter the human body, where it interferes with hormonal processes. This hormonal interference has been linked to cancer, heart disease, and obesity.