Per- and Polyfluoroalkyl Substances (PFAS)

PFAS are a group of man-made chemicals that includes Perfluorooctanoic acid(PFOA), Perfluorooctane sulfonic acid (PFOS), Hexafluoropropylene oxide dimer acid (HFPO-DA/GenX), Perfluorobutane sulfonic acid (PFBS), Perfluorononanoic acid acid (PFNA) and Perfluorohexane sulfonic acid (PFHxS) as well as many other chemicals. PFAS have been manufactured and used in a variety of industries around the globe, including in the United States since the 1940s.  There is evidence that exposure to PFAS can lead to adverse human health effects.

PFAS can be found in:

• Food packaged in PFAS-containing materials, processed with equipment that used PFAS, or grown in PFAS-contaminated soil or water.
• Commercial household products, including stain- and water-repellent fabrics, nonstick products (e.g., Teflon), polishes, waxes, paints, cleaning products, and fire-fighting foams (a major source of groundwater contamination at airports and military bases where firefighting training occurs).
• Workplace, including production facilities or industries (e.g., chrome plating, electronics manufacturing or oil recovery) that use PFAS.
• Drinking water, typically localized and associated with a specific facility (e.g., manufacturer, landfill, wastewater treatment plant, firefighter training facility).
• Living organisms, including fish, animals and humans, where PFAS have the ability to build up and persist over time.

National Primary Drinking Water Regulation for PFAS

On  April 26, 2024, EPA published the National Primary Drinking Water Regulation (NPDWR) for PFOA, PFOS, HFPO-DA/GenX, PFHxS, PFNA,  and PFBS. EPA has set a Maximum Contaminant Level (MCL) for PFOA, PFOS, HFPO-DA/GenX, PFHxS and PFNA (see table below) and to address the combination of four PFAS (HFPO-DA/GenX, PFBS, PFNA, and PFHxS) using a Hazard Index. The Hazard Index is a tool typically used to evaluate potential health risks from exposure to chemical mixtures.

PFAS Compound	MCLG	MCL	Standard Health Effects for public notice
PFOA	0 ppt	4.0 ppt	Some people, including children, who drink water containing PFOS/PFOA in excess of the MCL could develop immune health effects, fetal growth effects after exposure during pregnancy, certain types of cancers, or an increased risk of cardiovascular disease or liver disease.
PFOS
PFNA	10 ppt	10 ppt	Some people who drink water containing PFHxS, HFPO-DA, PFNA, and PFBS in excess of the Hazard Index MCL could develop thyroid, liver, or developmental health effects.
PFHxS
HFPO-DA/GenX
Hazard Index calculated using a mixture of PFHxS, PFNA, HFPO-DA, and PFBS	1 (unitless Hazard Index)	1 (unitless Hazard Index)

Helpful Links

• The U.S. Environmental Protection Agency - PFAS
• Guidance on PFAS Regulations
• Louisiana Drinking Water Watch - The drinking water watch allows consumers to review chemical and bacteriological data pertaining to their water system. (PFAS Search Criteria)