Perfluorinated compounds (PFCs) are a family of human-made substances that do not occur naturally in the environment. They have been used for decades as an ingredient to make products that resist heat, oil, stains, grease and water. They also are used in various products including firefighting foams, coating additives, and surface protection products for carpets and clothing. PFCs can also be found in certain types of food packaging, dental floss and cosmetic products. The main way people come into contact with PFCs is through food and personal care products. In fact, human contact with PFCs is widespread, and nearly all people have measureable levels of PFCs in their blood.