Do you enjoy the convenience and taste of microwave popcorn? According to a report from the Food and Drug Administration, a chemical coating inside microwave popcorn bags can break down if overheated. This chemical -- known as PFOA -- is a carcinogen that has been found in nonstick cookware and is now being phased out. Most microwave popcorns contain fake butter chemicals and hydrogenated oils, making it an unhealthy snack. If you like the convenience of microwave popcorn and don't want to pop popcorn the old-fashioned way, look for brands that use uncoated bags and natural ingredients.