Per- and Polyfluoroalkyl Substances (PFAS)

Private Wells and PFAS
PFAS Information for Municipalities
PFAS Information for Environmental Professionals
PFAS in Firefighting Foam
PFAS Task Force
Known PFAS Sources
Toxicity and Health Effects
PFAS in Food Packaging
PFAS in Wastewater Treatment Facilities
PFAS in Biosolids
PFAS in Surface Water and Fish

What are PFAS and why are they a problem?

Per- and polyfluorinated alkyl substances, or PFAS, are a group of over 12,000 manmade chemicals that have been used widely in consumer products and industry since the 1940s. Due to their unique chemical structure, PFAS are extremely stable and repel oil, grease, water, and heat. Despite their long history of use, scientific studies have shown PFAS have serious adverse impacts on human health and the environment, even at very low levels.

The same properties that make PFAS stable also make them extremely resistant to breaking down in the environment (persistent), giving them the nickname “Forever Chemicals.” PFAS also migrate easily in water and air, and because of their persistence, can travel far from where they were used or released to the environment.

Known PFAS Sources

PFAS have been manufactured and used worldwide since the 1940s. Due to their chemical stability, heat resistance, and ability to repel oil and water, PFAS are used in thousands of consumer products and industrial processes. The known sources of PFAS include:

  • Nonstick cookware
  • Grease-resistant and waterproof coatings on food packaging (e.g., popcorn bags, takeout containers, and fast food wrappers)
  • Coated paper products
  • Waterproof, water-resistant, and stain-resistant textiles (e.g., clothing, shoes, upholstery, and carpets)
  • Cosmetics and personal care products
  • Industrial and household cleaning products
  • Floor, car, and boat waxes
  • Engineered coatings used in semiconductor production
  • Metal plating and finishing
  • Etching of metals, plastics, and glass
  • Plastics, resins, and rubber products
  • Surface coating, paint, varnish, and inks
  • Cable and wire insulation for electronics
  • Aqueous Film-Forming Foam (AFFF) used to extinguish flammable liquid fires
  • Biosolids


Toxicity and Health Effects

Research on the human health and ecological impacts of PFAS is rapidly evolving. Some PFAS have been proven to accumulate within the body (bioaccumulate) in humans and animals when ingested. Certain PFAS have been linked to health risks including developmental effects in fetuses and infants; decreased liver, thyroid, and immune system function; high cholesterol, and kidney and testicular cancer..

PFAS in Food Packaging

In 2021, Public Act 21-191 was enacted, updating Connecticut’s Toxics in Packaging Law (Section 22a-255g-m of the Connecticut General Statutes) to restrict intentionally added PFAS in food packaging effective January 1, 2024. Questions related to this law and its PFAS provisions may be directed to Tom Metzner at 860-424-3242.

Toxics in Packaging

PFAS in Wastewater Treatment Facilities

Because of the widespread use of PFAS in household, commercial, and industrial products, PFAS are being detected in wastewater conveyed to wastewater treatment plants. PFAS are not destroyed or removed at these plants and can be found in both the liquids and solids generated during the treatment process. In Connecticut, most biosolids, or sewage sludge, generated at wastewater treatment plants are incinerated. Sludge incineration does not currently destroy PFAS compounds.

DEEP completed two rounds of PFAS sampling at about 40% (35) of the state’s publicly owned wastewater treatment plants in 2021-22. DEEP collected wastewater entering and discharging from each facility (influent and effluent), as well as sludge samples. DEEP also collected samples of “scrubber water” (water used to treat smokestack emissions) from four of the five facilities that maintain sewage sludge incinerators. A final report is expected in mid 2023.

PFAS in Biosolids

In Connecticut, most biosolids, or sewage sludge, generated at wastewater treatment plants are incinerated. In other states, the nutrient-rich biosolids are reused in agriculture as soil amendments or are made into pelletized fertilizers that are sold commercially, some of which have been found to contain PFAS.

The CT Department of Agriculture and DEEP recommend that farmers do not apply pelletized biosolid fertilizer to agricultural fields without first requesting PFAS test results from their suppliers. If the biosolid product contains a combined PFAS concentration of 1.4 micrograms per kilogram [ug/kg, or parts per billion (ppb)] or more for five specific PFAS chemicals [PFOA, PFOS, PFHxS, PFNA, and PFHpA], it is recommended that you do not apply that product in bulk to your fields. Higher PFAS concentrations have the potential to leach to groundwater and contaminate drinking water and irrigation supplies. PFAS has also been shown to be taken up by crops and accumulate in livestock. Research is ongoing.

PFAS in Biosolids Fact Sheet.
Basic Information about Biosolids | US EPA

PFAS in Surface Water and Fish

DEEP sampled surface water and fish tissue from ten streams for PFAS in 2021. Surface water samples were collected up and downstream of certain wastewater treatment plant discharge points and tissue samples from two fish species were also collected and analyzed for PFAS. A final report summarizing this sampling is expected in early 2023.

Elevated PFAS levels were identified in fish collected from the Hockanum River, causing the Department of Public Health to issue a Do Not Eat fish consumption advisory for the Hockanum River downstream of Lake Shenipsit in the Towns of Vernon, Ellington, Manchester, and East Hartford. DEEP is conducting additional fish, surface water and sediment testing for PFAS in the Hockanum River to further evaluate this issue.

Fish consumption advisories for PFAS also exist for the Natchaug, Willimantic and Shetucket Rivers in Willimantic and Mansfield based on prior sampling events.

Please note that fish consumption advisories exist throughout the state for other chemicals.
Anglers are advised to consult the most recent issue of DPH’s publication: If I Catch It, Can I Eat It? A Guide to Eating Fish Safely.

Contaminants of Emerging Concern

Content last updated March 20, 2023