PFCs, or perfluorochemicals, are a group of human-made chemicals used in the manufacturing of many everyday products. PFCs ensure that products resist heat, stains, grease, water and oil and have been used widely for items such as nonstick pans, stainresistant carpet, food packaging (such as fast food wrappers and microwave popcorn bags), etc. As a result of their prevalent use, there is widespread wildlife and human exposure across the globe to several PFCs, most commonly PFOA (perfluorooctanoic acid) and PFOS (perfluorooctane sulfonate). Both PFOA and PFOS were present in firefighting foam used by the United States Navy in firefighting activities on the Naval Air Base in Willow Grove, PA.
On May 19, 2016, the EPA issued a Lifetime Health Advisory (LHA) level of 70 parts per trillion (ppt), or 0.07 parts per billion (ppb), as the combined concentration of PFOS and PFOA permissible in drinking water. For reference, the last guidance the EPA provided on PFOS and PFOA was in 2009, when it issued a Provisional Health Advisory Level (PHAL) of .4 parts per billion (ppb) for PFOA and .2 parts per billion (ppb) for PFOS. The EPA calculated the permissable levels for its Lifetime Health Advisory with the most vulnerable humans (infants and fetuses) in mind.