Per- and Polyfluoroalkyl Substances (PFAS) are a vast collection of thousands of synthetic chemicals that share a common trait: a chain of carbon atoms bonded to fluorine atoms. Determining a single “invention” date is complicated because they emerged from decades of specialized chemical research rather than being discovered all at once. This historical journey traces how these unique chemical structures were first synthesized, leading to their widespread commercial use and the eventual recognition of their environmental persistence.
The Genesis of Fluorochemistry
The foundation for PFAS was laid in the late 19th and early 20th centuries with the isolation of the element fluorine. French chemist Henri Moissan succeeded in isolating elemental fluorine in 1886 due to its extreme reactivity. This isolation was a prerequisite for creating organofluorine compounds, which are molecules containing carbon-fluorine bonds.
Fluorine is the most electronegative element, resulting in a highly polarized and short chemical bond with carbon. The carbon-fluorine (C-F) bond is one of the strongest single bonds known in organic chemistry, requiring significant energy to break. This inherent strength and stability, combined with the chemical inertness of the surrounding fluorine atoms, became the scientific basis for the unique properties of all future PFAS compounds.
The First Breakthroughs and Commercialization
The modern era of PFAS began with an accidental discovery. In 1938, chemist Roy J. Plunkett, working at DuPont’s Kinetic Chemicals laboratory in New Jersey, was attempting to create a refrigerant gas. He found that a frozen, compressed sample of tetrafluoroethylene gas had spontaneously polymerized, forming a white, waxy solid.
This substance was Polytetrafluoroethylene (PTFE), which demonstrated remarkable non-stick properties and high chemical and heat stability. DuPont patented the discovery in the early 1940s and trademarked the material as Teflon in 1945, initially limiting its use to specialized military and industrial applications.
Around the same time, another foundational process for creating liquid PFAS was developed. In 1945, the Minnesota Mining and Manufacturing Company (3M) licensed the Simons Process, which used electrochemical fluorination to synthesize organofluorine molecules. This process allowed for the creation of liquid fluorosurfactants, including the precursors to perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). DuPont began using PFOA in 1951 to process and manufacture its PTFE product line, while 3M used PFOS in its own innovative products.
Broadening Applications and Industrial Expansion
Starting in the 1950s, the ability of PFAS compounds to repel both oil and water made them highly desirable for consumer goods requiring stain and moisture resistance. 3M commercialized PFOS-based products like Scotchgard, a fabric protector widely marketed for use on carpets and upholstery.
The unique surfactant properties of PFAS also proved invaluable in specialized industrial and military contexts. In the mid-1960s, the U.S. Navy collaborated with 3M to develop Aqueous Film-Forming Foam (AFFF), a highly effective fire suppressant for liquid fuel fires. AFFF contained high concentrations of PFOS and PFOA, which created a fast-spreading film that quickly smothered petroleum-based flames. Production continued to expand throughout the 1970s and 1980s, incorporating various PFAS into specialized coatings, polishes, food packaging, and electronics.
Recognition of Persistence and Regulatory Response
Early warning signs about the chemicals’ fate in the environment began to emerge from internal company studies as early as the 1950s and 1960s. Researchers at 3M and DuPont found that PFOA and PFOS could accumulate in the blood of animals and workers. By the 1970s, scientists were documenting the presence of PFOA and PFOS in fish and the wider environment, an early indication of their persistence.
The scientific realization that these substances were not biodegradable and could bioaccumulate in living organisms led to a major shift in the late 1990s and early 2000s. Faced with increasing evidence of environmental contamination, 3M announced a voluntary phase-out of PFOS production in 2000. This was followed by a 2006 agreement brokered by the Environmental Protection Agency (EPA) with eight major companies to voluntarily phase out the production and use of PFOA and related long-chain PFAS chemicals by 2015. More recently, the EPA has taken formal regulatory action, including designating PFOA and PFOS as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA).