Research on Per- and Polyfluoroalkyl Substances (PFAS)
Per- and polyfluoroalkyl substances (PFAS) are a class of chemicals that have been used in industry and consumer products for decades, and they continue to be used today. Certain PFAS, such as PFOA and PFOS, do not breakdown in the environment, can build up in living things, and can adversely impact human health and the environment.
In 2021, EPA released its PFAS Strategic Roadmap, which lays out EPA’s whole-of-agency approach to addressing PFAS. Science plays a vital role in EPA’s integrated approach to PFAS.
On this page:
- Methods to detect and measure PFAS in the environment
- Understanding human health and environmental risks from PFAS
- Ways to reduce PFAS in the environment
- More PFAS information
See the PFAS extramural research webpage for information on PFAS research and development funding opportunities.
Robust, accurate methods for detecting and measuring PFAS in air, land, and water are essential for understanding which PFAS are in the environment and how much are present. These methods are also essential for evaluating how effective different technologies are at removing PFAS from air, land, and water and for implementing future regulations. To address this need, EPA researchers are developing methods to detect and measure PFAS in the environment. EPA is also partnering with other laboratories to test and validate methods to ensure that government and private laboratories can accurately and consistently measure PFAS in the environment.
For more information: PFAS Analytical Method Development
- Total oxidizable precursor (TOP) assay: Best practices, capabilities, and limitations for PFAS site investigation and remediation
- Practical application guide for the discovery of novel PFAS in environmental samples using high resolution mass spectrometry
Recent scientific publications related to methods:
- Geophysical signatures of soil AFFF contamination from spectral induced polarization and low field nuclear magnetic resonance methods
- Method development for thermal desorption-gas chromatography-tandem mass spectrometry (TD-GC-MS/MS) analysis of trace level fluorotelomer alcohols emitted from consumer products
- Analytical method interferences for perfluoropentanoic acid (PFPeA) and perfluorobutanoic acid (PFBA) in biological and environmental samples
Assessing risks to human health or the environment from PFAS involves understanding exposure to PFAS and understanding how harmful PFAS are to humans and other living things.
To improve our understanding of exposure, EPA is conducting research to identify PFAS sources and occurrence in the outdoor and indoor environment, characterize how PFAS moves through the environment, and identify the relative importance of ways we might be exposed to PFAS (e.g., ingestion of contaminated food or water, interaction with household articles or consumer products, and inhalation of indoor or outdoor air containing PFAS).
Recent scientific publications related to exposure:
- Distribution of select PFAS at a chemical manufacturing plant
- Subsurface PFAS distribution at two contaminated sites
- Using geospatial data and random forest to predict PFAS contamination in fish tissue in the Columbia River Basin, United States
To improve our understanding of the toxicity of PFAS, EPA researchers are developing toxicity assessments to inform actions to protect human health and the environment. EPA’s Integrated Risk Information System (IRIS) Program is developing human health toxicity assessments for PFBA, PFHxA, PFHxS, PFNA, and PFDA. EPA can use these toxicity assessments, along with exposure information and other considerations, to assess human health risk. The current status of these assessments is available through the IRIS Program Outlook. EPA researchers are also developing other targeted assessments to support actions to protect human health. Once final, EPA may use these toxicity assessments, along with exposure information and other considerations, to assess risk and when appropriate, inform actions to address potential risks.
Final human health toxicity assessments:
- IRIS Toxicological Review of Perfluorobutanoic Acid (PFBA) and Related Salts
- IRIS Toxicological Review of Perfluorohexanoic Acid (PFHxA) and Related Salts
- Human Health Toxicity Values for Perfluorobutane Sulfonic Acid (PFBS) and Related Compound Potassium Perfluorobutane Sulfonate
- Human Health Toxicity Values for Hexafluoropropylene Oxide Dimer Acid and its Ammonium Salt (also known as “GenX Chemicals”)
- Human Health Toxicity Value for Perfluoropropanoic Acid (PFPrA)
- Human Health Toxicity Value for Lithium bis[(trifluoromethyl)sulfonyl]azanide (HQ-115)
EPA's toxicity assessments on PFAS are important to inform actions. However, most PFAS have limited or no toxicity data to inform toxicity assessments. To address this need for more toxicity data across a wider variety of PFAS, EPA researchers are compiling and summarizing the available scientific information on PFAS and conducting toxicity testing on individual PFAS and PFAS mixtures. These research activities help to define the landscape of PFAS found in the environment, develop and refine PFAS categories for assessment, and assist EPA in prioritizing PFAS for toxicity assessment.
- CompTox Chemicals Dashboard
- ECOTOX Knowledgebase
- Systematic Evidence Maps for Over 150 PFAS
- National PFAS Testing Strategy
Recent scientific publications related to toxicity:
- In vitro screening of PFAS for interference with seven thyroid hormone system targets across nine assays
- Dose additive maternal and offspring effects of oral maternal exposure to a mixture of three PFAS (HFPO-DA, NBP2, PFOS) during pregnancy in the Sprague-Dawley rat
- PFAS in mixtures show additive effects on transcriptomic points of departure in human liver spheroids
To reduce PFAS that is already in our environment, EPA and others need data on the effectiveness of technologies and approaches that aim to remove, treat, and manage PFAS and PFAS-containing materials from the environment. This information is needed to inform decisions on drinking water and wastewater treatment, contaminated site cleanup and remediation, air emission controls, and end-of-life materials management. This information is also needed to better ensure that remediation approaches do not lead to additional PFAS exposures, particularly in overburdened communities where treatment and waste management facilities are often located.
EPA researchers are developing and evaluating technologies for drinking water and wastewater treatment, contaminated site remediation, air emission controls, and destruction and disposal of PFAS-containing materials and waste streams. These efforts include conducting laboratory- and pilot-scale studies, which will inform the design of full-scale field studies. Full-scale field studies are organized in partnership with facilities and states and help EPA evaluate real-world applications of different PFAS removal technologies and management approaches.
- PFAS Thermal Treatment Database
- Drinking Water Treatability Database
- EPA Interim Guidance on the Destruction and Disposal of PFAS and Materials Containing PFAS
Recent scientific publications related to water treatment:
- Strong base anion exchange selectivity of nine PFAS relevant to drinking water
- Impact of phosphate addition on PFAS treatment performance for drinking water
- Polanyi adsorption potential theory for estimating PFAS treatment with granular activated carbon
Recent scientific publications related to destruction and disposal:
- Photocatalysts for chemical-free PFOA degradation: What we know and where we go from here
- Photodegradation and photocatalysis of PFAS: A review of recent progress
- A critical review of PFAS landfill disposal in the United States