Most people know that some plastics additives, such as bisphenol A (BPA), may be harmful to their health. But an upcoming study in the journal Environmental Health finds that entire classes of plastics—including the type commonly referred to as styrofoam and a type used in many baby products—may wreak havoc on your hormones regardless of what additives are in them.
The study's authors tested 14 different BPA-free plastic resins, the raw materials used to make plastic products, and found that four of them released chemicals that mimic the female hormone estrogen. That's not surprising.
As Mother Jones reported earlier this year, many BPA-free plastic goods—from baby bottles and sippy cups to food-storage containers—leach potentially harmful estrogenlike chemicals. But until now, it wasn't clear what role the resins played. The new study suggests that sometimes the resins themselves are part of the problem, though additives such as dyes and antioxidants can make it worse.