Research on Per- and Polyfluoroalkyl Substances (PFAS)

The EPA is leading the national effort to understand PFAS and reduce PFAS risks to the public. Per- and polyfluoroalkyl substances (PFAS) are a group of synthetic chemicals that have been in use since the 1940s. PFAS are found in a wide array of consumer and industrial products. PFAS manufacturing and processing facilities, facilities using PFAS in production of other products, airports, and military installations are some of the potential contributors of PFAS releases into the air, soil, and water. Due to their widespread use and persistence in the environment, most people in the United States have been exposed to PFAS. There is evidence that continued exposure above specific levels to certain PFAS may lead to adverse health effects.

The EPA will continue to partner with other federal agencies, states, tribes, and local communities to protect human health and, where necessary and appropriate, to limit human exposure to potentially harmful levels of PFAS in the environment.

On this page:

• PFAS Chemicals Currently Being Studied
• Developing and Validating Analytical Methods
• Assessing PFAS toxicity
• Researching PFAS Exposure
• Testing Drinking Water Treatment Options
• Cleaning up Contaminated Sites
• Managing PFAS Containing Materials and Waste
• Resources and Publications

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PFAS Chemicals Currently Being Studied

EPA researchers are developing analytical chemistry methods to detect and quantify PFAS; they are gathering and assessing data on chemical toxicity and environmental exposures for PFAS of highest concern; and our researchers are summarizing data and conducting studies to determine the effectiveness and cost of different technologies for treating or removing PFAS in drinking water and contaminated sites. Based on a number of factors, including occurrence in the environment and limited information about potential health risks, the researchers are focusing on a working list of PFAS chemicals with research interest.

In addition, another group of PFAS chemicals have been selected specifically for their range of chemical diversity and lack of toxicological and toxicokinetic information and are being evaluated using computational and high throughput toxicology tools. That list of PFAS chemicals can be found here:
EPA and Partners Describe a Chemical Category Prioritization Approach to Select 75 PFAS for Testing using New Approach Methods

Developing and Validating Analytical Methods

EPA researchers are developing and validating laboratory methods to detect and quantify selected PFAS in air, water, and soil. EPA recently released a revised version of EPA Method 537.1 for additional PFAS (e.g. Hexafluoropropylene oxide dimer acid (HFPO-DA), a GenX chemical) in drinking water. More in depth information is available on the PFAS Analytical Methods Development and Sampling Research page. 

Currently, EPA researchers are working on:

• Validating methods under EPA’s SW-846 to measure certain PFAS in groundwater, surface water, wastewater, and solids (e.g., soils, sediments, and sewage). EPA recently posted a draft method to measure a group of 24 PFAS compounds in groundwater, surface water, and wastewater samples. Once final, it will be included in the SW846 Compendium.
• Developing and testing sampling and analytical methods for identifying and quantifying PFAS in air and stack emissions.
• Extending the use of non-targeted chemical analysis for air emissions and solids.

Tested and validated methods are important for ensuring that government and private laboratories can accurately and consistently measure PFAS in the environment, which is critical for estimating exposure and risk. These methods can be used by federal agencies, states, tribes, and local communities.

• Method 537.1: Determination of Selected Per- and Polyfluorinated Alkyl Substances in Drinking Water by Solid Phase Extraction and Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS)
• The SW-846 Compendium
• Validated Test Method 8327: Per-and Polyfluoroalkyl Substances (PFAS) Using External Standard Calibration and Multiple Reaction Monitoring (MRM) Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS)

Related Information: EPA Office of Water Clean Water Act Methods for PFAS

Assessing PFAS Toxicity

EPA researchers are developing standard human health toxicity reference values for specific PFAS where sufficient scientific data exist. These values will enable risk assessors in states, tribes, and local communities, in conjunction with knowledge on exposure, to assess the risks and make decisions about managing PFAS to protect human health and the environment.  Results of a preliminary literature search of published toxicity studies are available for 31 PFAS of interest to EPA; draft assessments for PFBS and HFPO-DA (GenX chemicals) were posted for public comment and the assessments are currently being finalized. Assessments are underway for PFBA, PFHxS, PFHxA, PFDA, PFNA.

• Final Human Health Toxicity Assessment for PFBS
• Final Human Health Toxicity Assessment for GenX Chemicals

EPA researchers are also applying computational and high throughput toxicology tools for PFAS toxicity testing on a larger scale to enable faster understanding of potential toxicity for the universe of thousands of PFAS, most of which have little or no published toxicity data. Learn more about EPA's PFAS testing methods. In addition, EPA researchers are generating and gathering scientific information on ecological toxicity which is being loaded into the ECOTOX knowledgebase and used to identify susceptible species, understand bioaccumulation, and support decisions to protect ecosystems.

• Results from literature search for Per- and Polyfluoroalkyl Substances (PFAS)
• PFAS Chemical Lists and Tiered Testing Methods Descriptions
• ECOTOX Knowledgebase

Researching PFAS Exposure

EPA researchers are measuring PFAS in air, drinking water, soils, etc., to understand how and to what degree people might be exposed to PFAS. This research includes modeling human population exposures to better understand the relative contributions of different sources and pathways for PFAS. This will help states, tribes, and local communities to assess potential risks and, as necessary choose the most effective methods for protecting public health.

Testing Drinking Water Treatment Options

EPA researchers continue to evaluate different drinking water treatment technologies that can remove certain PFAS from drinking water systems. They are evaluating systems across the nation currently treating PFAS and gathering data on cost and performance. Researchers are also testing modifications needed to improve treatment. This research is being conducted in cooperation with drinking water utilities and with other federal agencies.

Researchers will generate performance and cost data with collaborators to develop models and provide tools to enable local communities to determine optimal treatment choices based on their specific needs and circumstances.

This work is incorporated into the Drinking Water Treatability Database, which helps drinking water utilities, communities, states, academics, and more identify effective treatment processes. So far, EPA research has helped update the Database with 22 PFAS chemicals.

Drinking Water Treatability Database

Cleaning up Contaminated Sites

EPA researchers are developing methods for characterizing PFAS releases and movement in soil, water, and sediments at contaminated sites, so that site managers can understand the scope and magnitude of such contamination to decide how best to respond. Researchers are also developing and testing methods for treating, removing, or immobilizing PFAS at such sites, to provide site managers with tools for site remediation. Some of this work is being done in collaboration with the Department of Defense on current and former military bases. For example, EPA and DoD recently collaborated on a field study to evaluate a commercial PFAS-contaminated soil thermal treatment technology near Fairbanks Alaska.  

Managing PFAS Containing Materials and Waste

EPA researchers are characterizing how end-of-life disposal approaches, such as landfills, incinerators, and recycling might contribute to PFAS in the environment.

They are also evaluating waste management technologies such as thermal treatment and composting, that may be useful and cost-effective to manage consumer and industrial products at end-of-life disposal.

Technical Brief on Per- and Polyfluoroalkyl Substances (PFAS): Incineration to Manage PFAS Waste Streams

Read the PFAS Innovative Treatment Team Research Briefs

Resources and Publications

• EPA Publications about PFAS Research
• Determining global background soil PFAS loads and the fluorotelomer-based polymer degradation rates that can account for these loads
• Investigations of per- and polyfluorinated compounds in environmental samples and contemporary products 2019 North Carolina Water Quality Workshop)