Harmful Ingredient: BPA (Bisphenol-A). BPA (one of these Scary Toxins Hiding in Your Cookware and Storage Containers) is a hormone-mimicking chemical found in nearly all food packaging plastics, and it’s potentially bad news. Active in just parts per billion, one of the things BPA is known for is causing men to grow breasts by disrupting their hormones. It can also promote cancer and render people infertile.