Those little bags of popcorn are so convenient to just stick in the microwave, you wouldn’t think for a minute that they could be dangerous to your health, but they are. First, let’s talk about the bag itself. It’s lined with a chemical called perfluorooctanoic acid ( PFOA). This is a toxin you can find in Teflon also. After being heated, this toxic chemical is known to cause infertility and cancer in lab animals. The EPA lists this chemical as a known carcinogen.