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 Science Inventory for a list of publications on PFAS authored or co-authored by EPA researchers.
See the PFAS extramural research webpage for information on PFAS research and development funding opportunities.
Methods to Detect and Measure PFAS in the Environment
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
Publication highlights related to methods:
- Laboratory development and validation of vapor phase PFAS methods for soil gas, sewer gas, and indoor air
- A high-efficiency method for the extraction and quantitative analysis of 45 PFAS in whole fish
- Development of a standardized adsorbable organofluorine screening method for wastewaters with detection by combustion ion chromatography
- Method development for thermal desorption-gas chromatography-tandem mass spectrometry (TD-GC-MS/MS) analysis of trace level fluorotelomer alcohols emitted from consumer products
- Practical application guide for the discovery of novel PFAS in environmental samples using high resolution mass spectrometry
- Measuring short-chain PFAS in central New Jersey air using chemical ionization mass spectrometry
- A review of sample collection, analytical methods, and distribution of PFAS in indoor and outdoor air
Understanding Human Health and Environmental Risks from PFAS
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).
Publication highlights related to exposure:
- Emerging Per- and Polyfluoroalkyl Substances in Tap Water from the American Healthy Homes Survey II
- Per- and polyfluoroalkyl substances (PFAS) in paired tap water and house dust from United States homes
- Analysis of Legacy and Novel Neutral Per- and Polyfluoroalkyl Substances in soils from an Industrial Manufacturing Facility
- Measuring short-chain per- and polyfluoroalkyl substances in Central New Jersey air using chemical ionization mass spectrometry
- Characterization of PFAS air emissions from simulated thermal fabric application processes
- Distribution of select PFAS at a chemical manufacturing plant
- Subsurface PFAS distribution at two contaminated sites
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
- IRIS Toxicological Review of Perfluorohexanesulfonic Acid (PFHxS) and Related Salts
- IRIS Toxicological Review of Perfluorodecanoic Acid (PFDA) and Related Salts
- Human Health Toxicity Assessment for Perfluorooctanoic Acid (PFOA) and Related Salts
- Human Health Toxicity Assessment for Perfluorooctane Sulfonic Acid (PFOS) 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 Transcriptomic Assessment Product for Perfluoro-3-methoxypropanoic acid (MOPA)
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.
Related resources:
Publication highlights related to toxicity:
- Development of chemical categories for per- and polyfluoroalkyl substances (PFAS) and the proof-of-concept approach to the identification of potential candidates for tiered toxicological testing and human health assessment
- Estimation of species- and sex-specific PFAS pharmacokinetics in mice, rats, and non-human primates using a Bayesian hierarchical methodology
- Epidemiology evidence for health effects of 150 per- and polyfluoroalkyl substances: a systematic evidence map
- Systematic Evidence Maps for Over 150 PFAS
- Expanded Systematic Evidence Maps for PFAS and Comprehensive Human Health Dashboard
- Systematic Evidence Map for the Per- and Polyfluoroalkyl Substances (PFAS) Universe
- A comparison of in vitro points of departure with human blood levels for PFAS
Ways to Reduce PFAS in the Environment
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.
Related resources:
- PFAS Thermal Treatment Database
- Drinking Water Treatability Database
- EPA Interim Guidance on the Destruction and Disposal of PFAS and Materials Containing PFAS
Publication highlights related to water treatment:
- Mineralogical controls on PFAS and anthropogenic anions in subsurface soils and aquifers
- Anion exchange resin and inorganic anion parameter determination for model validation and evaluation of unintended consequences during PFAS 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
- A critical review of PFAS landfill disposal in the United States
Publication highlights related to destruction and disposal:
- Thermal treatment of hexafluoropropylene oxide dimer acid (HFPO-DA) using a pilot-scale research combustor
- Comparative evaluation of PFAS-selective adsorbents in hard-to-treat residual waste streams
- The use of air pollution controls to reduce the gas-phase emissions of per- and polyfluoroalkyl substances from a fluoropolymer manufacturing facility
- Pilot‐scale thermal destruction of per‐ and polyfluoroalkyl substances in a legacy aqueous film forming foam
- Characterizing volatile emissions and combustion by-products from aqueous film-forming foams using online chemical ionization mass spectrometry
- Characterization of PFAS and other constituents in municipal solid waste landfill leachate from Puerto Rico
- Photodegradation and photocatalysis of PFAS: A review of recent progress