A new study suggests that whole classes of BPA-free plastics—including the kind in styrofoam—release estrogenic chemicals.
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.
In the case of polystyrene, the resin used in styrofoam and similar products, the authors tested 11 samples and consistently found estrogen seepage after exposure to intense steam or ultraviolet rays.
Styrofoam is a registered trademark of Dow. The company stresses that its product is used for crafts and building insulation, not food and beverage containers. (“There isn’t a coffee cup, cooler, or packaging material in the world made from actual Styrofoam,” according to Dow’s website.) But generic polystyrene foam, which most people call styrofoam anyway, is ubiquitous in the food services industry, where its found in everything from meat trays to takeout containers. Polystyrene resin—which the Environmental Protection Agency has labeled a suspected carcinogen—is also used to make hard plastic items, including utensils and toothbrushes.