Per- and polyfluoroalkyl substances, or PFAS, are a large family of synthetic chemicals manufactured and used in industry since the mid-20th century. These compounds are defined by a chain of carbon atoms bonded to fluorine atoms. This unique structure provides remarkable resistance to heat, water, grease, and oil, making them highly desirable for countless applications. Because this carbon-fluorine bond is so stable, PFAS do not break down naturally in the environment or the human body for extremely long periods. This persistence led to their common nickname: “forever chemicals.”
The Chemical Genesis: Discovery and Early Patents
The scientific breakthrough that led to the creation of the first PFAS occurred in the 1930s. In 1938, Dr. Roy J. Plunkett, a chemist at DuPont’s Jackson Laboratory, was experimenting with tetrafluoroethylene (TFE) gas while developing new refrigerants. He discovered that a cylinder had spontaneously polymerized into a white, waxy solid. This new substance was polytetrafluoroethylene, or PTFE, which exhibited extreme chemical inertness and an incredibly low coefficient of friction, making it the slipperiest material known at the time.
DuPont quickly recognized the potential of this fluoropolymer and filed a patent for PTFE in 1941, trademarking the name Teflon in 1945. The material’s immediate application was not in consumer goods but in the highly specialized environment of the Manhattan Project during World War II. PTFE was used to create gaskets and liners to handle uranium hexafluoride gas required for atomic weapon development, proving its exceptional stability under harsh conditions.
First Commercial Applications
Following the wartime industrial use, the first commercial products containing PFAS began to appear on the market in the late 1940s and 1950s. The first major product, Teflon, was sold commercially under its trademark starting in 1946, initially as a coating for machined metal parts. Widespread household recognition came in the 1950s when a French engineer discovered how to bond PTFE to aluminum, leading to the creation of the first non-stick frying pans by 1954.
A separate discovery at 3M led to the development of another major PFAS product, Scotchgard, which used different fluorochemicals. In 1953, a 3M lab technician spilled a fluorochemical liquid on her tennis shoes and observed that the stain was impervious to common cleaning methods. This led to the development of stain-repellent coatings for fabrics, with sales beginning in 1956.
These initial commercial launches by DuPont and 3M introduced the public to the properties of PFAS, such as non-stick surfaces and stain repellency. The compounds central to these early products were primarily PFOA (used in PTFE manufacturing) and PFOS (an ingredient in the original Scotchgard formulation). This period marked the first widespread consumer exposure, setting the stage for broader industrial expansion.
The Era of Widespread Industrial Use
The success of these first consumer products fueled the diversification and scale of PFAS applications from the 1960s through the 1990s. Beyond cookware and stain repellents, manufacturers leveraged the chemicals’ stability for specialized industrial and military uses. A significant development occurred in 1963 when the U.S. Navy patented aqueous film-forming foams (AFFF), which used PFAS to create an effective film for extinguishing fuel fires.
This expansion saw PFAS integrated into lubricants, specialized electronics, and high-performance textiles. For example, expanded PTFE (ePTFE), known commercially as Gore-Tex, revolutionized outdoor apparel by providing a waterproof and breathable fabric. The chemicals were also incorporated into food packaging, such as grease-resistant paper, and utilized in components for the automotive and aerospace industries. This widespread production and use across diverse sectors led to their distribution into the environment.
The Historical Turning Point: Initial Health Concerns
The narrative of unchecked usage began to change in the late 1990s and early 2000s, marking the start of public and regulatory scrutiny. Internal studies at 3M and DuPont dating back to the 1970s had indicated that PFAS could accumulate in the blood of workers and animals, suggesting potential toxicity. This information began to surface in the late 1990s, leading to the first significant public awareness of contamination.
In 1998, 3M provided evidence to the Environmental Protection Agency (EPA) that PFAS accumulated in human blood. By 1999, the EPA began investigating the class of chemicals used in Scotchgard. This pressure culminated in 3M’s announcement in May 2000 that it would phase out the production of PFOS and PFOA due to concerns over their persistence and toxicity. This phase-out, alongside the first major lawsuits and the discovery of widespread contamination in public water supplies, established a historical turning point away from the chemicals’ unregulated use.