PFAS

PFAS
Name	Per- and polyfluoroalkyl substances
Caption	Representative perfluorinated and polyfluorinated structures
Formula	various
Other names	PFAS family

PFAS are a large family of synthetic organic compounds characterized by carbon–fluorine bonds. Widely manufactured since the mid‑20th century, they appear in industrial products, consumer goods, firefighting foams, and manufacturing processes. Notable for chemical stability and persistence, they have become global contaminants detected in water, soil, wildlife, and humans.

Overview

PFAS were developed by firms such as 3M, DuPont, and E. I. du Pont de Nemours and Company and used in products sold by companies like Teflon (a brand associated with Chemours), Scotchgard (originally by 3M), and AFFF formulations employed by United States Department of Defense facilities. Scientific study accelerated after incidents involving releases at sites like Parkersburg, West Virginia and contamination near Paducah, leading to litigation involving plaintiffs and firms including DuPont and settlements adjudicated in courts such as the United States District Court for the District of Ohio. Regulators such as the United States Environmental Protection Agency and agencies in the European Union and Australia have developed advisories, rules, and phase‑outs. High‑profile reporting by outlets like The New York Times and investigative work by organizations including Environmental Working Group raised public awareness and spurred research at universities such as Harvard University and Duke University.

Chemistry and Classes

PFAS comprise perfluoroalkyl acids, fluorotelomers, sulfonates, and related moieties studied by chemists at institutions like Massachusetts Institute of Technology, ETH Zurich, and University of California, Berkeley. Subclasses include perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), fluorotelomer alcohols, and GenX compounds developed by Chemours. Analytical chemistry methods developed at laboratories such as USGS labs and academic groups employ techniques tied to instrumentation from Agilent Technologies and Thermo Fisher Scientific for liquid chromatography–mass spectrometry used to measure chain length, functional groups, and precursor compounds. International standards bodies like ISO and regulatory science panels convened by World Health Organization experts have debated nomenclature and hazard classifications.

Sources and Uses

Primary industrial sources include fluoropolymer manufacture at plants operated historically by 3M and DuPont affiliates, firefighting training sites used by US Navy bases and municipal airports, textile finishing by firms supplying brands such as Patagonia and The North Face, and nonstick cookware sold under Teflon branding. Consumer products from retailers like Walmart and Amazon have contained treated fabrics, shampoos, and grease‑resistant food packaging originating in supply chains tied to manufacturers in China and South Korea. Waste streams from wastewater treatment plants studied by researchers at University of Minnesota and University of Michigan reveal transformation of precursors to terminal acids that enter municipal biosolids and landfills, with downstream impacts observed in regions including Midwest United States and Northern Europe.

Environmental Fate and Transport

PFAS behavior in the environment has been characterized by field studies near sites such as Philadelphia Navy Yard and the Shin‑Etsu Chemical facilities in Japan. Their high mobility in groundwater and resistance to degradation lead to plumes documented by state agencies like the Minnesota Pollution Control Agency and the New Jersey Department of Environmental Protection. Atmospheric transport of volatile precursors has been modeled by teams at NOAA and National Aeronautics and Space Administration, while bioaccumulation in species monitored by US Fish and Wildlife Service and the European Chemicals Agency includes fish, seabirds, and marine mammals studied by researchers at Woods Hole Oceanographic Institution and Scripps Institution of Oceanography.

Human Health Effects and Toxicology

Epidemiological cohorts such as the C8 Science Panel and long‑running population studies at NIH and University of Cincinnati have linked certain PFAS to altered lipid metabolism, immune modulation, thyroid disruption, and developmental outcomes. Toxicologists at institutions like National Institute of Environmental Health Sciences and Harvard T.H. Chan School of Public Health have evaluated dose–response relationships, biomonitoring evidence from programs like CDC’s National Health and Nutrition Examination Survey, and mode‑of‑action data including peroxisome proliferator‑activated receptor signaling. Litigation and regulatory assessments have focused on substances such as PFOA and PFOS, while newer replacements (e.g., GenX) prompt toxicology testing by groups including European Food Safety Authority and independent labs.

Regulation and Remediation

Regulatory responses include advisory levels and regulatory limits set by agencies such as the United States Environmental Protection Agency, enforceable standards in European Union law via REACH, and national measures in Canada and Japan. Remediation approaches tested at Superfund sites and military bases include activated carbon adsorption piloted by contractors like Bechtel, ion exchange resin systems used by utilities such as Water Corporation (Western Australia), advanced oxidation research by universities, and thermal destruction trials examined by engineering firms like Jacobs Engineering. Emerging technologies involve electrochemical reduction, plasma treatment studied at Argonne National Laboratory, and in situ stabilization trials overseen by state remediation programs such as Massachusetts Department of Environmental Protection.

Category:Environmental chemistry Category:Persistent organic pollutants