A glossary of terms

PFCs: A family of chemicals called perfluorinated compounds. A perfluorinated chemical is one in which all the carbon-hydrogen bonds in a chain have been replaced by carbon-fluorine ones. All fully fluorinated chemicals are manmade.

PFOA: Perfluorooctanoic acid, the best-known chemical in this group. PFOA was used in nonstick cookware and produced by the breakdown of other PFCs used in fast-food wrappings and other stain-resistant coatings.

The U.S. Environmental Protection Agency is investigating the health effects of PFOA, which has turned up in the blood of 96 percent of children tested in 23 U.S. states, river otters in Oregon, and polar bears in the Canadian Arctic.

PFOS: Perfluorooctane sulfonate, which was used to manufacture Scotchgard stain repellant.

PFBA: Perfluorobutanoic acid. PFBA was made by 3M at its Cottage Grove facility, reportedly for use in film coatings. PFBA may also be a breakdown product of other PFCs. Its impact on human health has not been determined.

Health Based Value: A health-based value, also known as HBV, is the amount of a chemical in drinking water considered by the Minnesota Department of Health to be safe for people to drink daily for up to a lifetime. HBVs are advisory values, and are used by state health and environmental programs as one tool for deciding what actions should be taken.