"The EPA has set a health advisory, not a legal limit, for the combined total of PFOAs and PFOS, those are the Teflon and Scotchgard non-stick chemicals, and their value at 70 parts per trillion. Based on the latest science, we think that a safe level of exposure is one part per trillion," said EWG's David Andrews.
Andrews says about 600 new PFAS chemicals have been produced in the last decade and they're in everything: slick papers used in fast food preparation, rain repellant clothing, even dental floss.
"The Glide floss, at least some of the Glide floss, have advertised the use of these compounds to make them more slippery on your teeth," he said.
The Philadelphia Water Department declined comment until it could review the EWG survey. Pennsylvania is currently working to set it's own maximum contaminant level for PFAS because the EPA is unwilling to set a national standard. New Jersey's MCL is 14 parts per trillion.