A recent study of commercially available plastic products has reportedly claimed that “almost all” those sampled leached chemicals having reliably detectable estrogenic activity (EA). Chun Z. Yang, et al., “Most Plastic Products Release Estrogenic Chemicals: A Potential Health Problem That Can Be Solved,” Environmental Health Perspectives, March 2011. Researchers evidently used “a very sensitive, accurate, repeatable, roboticized MCF-7 cell proliferation assay to quantify the EA of chemicals leached into saline or ethanol extracts of many types of commercially available plastic materials, some exposed to common-use stresses,” such as microwaving or UV radiation.

The results indicated that these products, “independent of the type of resin, product, or retail source,” emitted chemicals having EA despite being advertised as EA-free. In particular, products labeled free of bisphenol A (BPA) sometimes released chemicals “having more EA than BPA-containing products,” according to the study’s authors, who pointed to “existing, relatively-expensive monomers and additives that do not exhibit [EA]” as a potential commercially-viable alternative to these plastics.