The safety debate over plastic products has centered largely on BPA, but many BPA-free items may be exposing us to harmful chemicals with similar effects. Neuroscientist George Bittner and his colleagues tested 455 products, from plastic wrap to food containers, and found that 72 percent leached some amount of synthetic estrogens. Here’s a guide to common plastics (often identifiable by the number stamped on them) and the percentage of samples that displayed estrogenic activity.