Perfluorooctanoic acid

Based on Wikipedia: Perfluorooctanoic acid

The Chemical That Refused to Die

In 1961, scientists at DuPont made a troubling discovery: mice fed a particular industrial chemical were developing enlarged livers. The company buried this finding. Over the next four decades, they would learn much more about this substance—that it caused cancerous tumors in lab animals, that it had contaminated the drinking water of entire communities, that it had somehow found its way into the blood of virtually every human being on Earth. And still, they kept making it.

This chemical is called perfluorooctanoic acid. Chemists abbreviate it as PFOA. Industry insiders call it simply C8, a nod to the eight carbon atoms in its molecular backbone. Whatever you call it, this compound has become one of the most notorious pollutants in history—not because it's the most toxic, but because it refuses to go away.

What Makes PFOA So Unusual

To understand why PFOA matters, you first need to understand what makes it chemically remarkable.

Most molecules in the natural world break down eventually. Sunlight splits them apart. Bacteria digest them. Water dissolves them. The carbon-based chemistry of life on Earth has evolved elaborate mechanisms for dismantling and recycling organic matter.

PFOA defeats all of these processes.

The secret lies in its fluorine atoms. In ordinary organic molecules, carbon atoms bond to hydrogen. But in PFOA and related compounds, those hydrogen atoms have been replaced with fluorine—every single one of them, across a chain of seven carbon atoms. This substitution changes everything.

The carbon-fluorine bond is one of the strongest in all of chemistry. Fluorine grips carbon so tightly that the usual mechanisms of degradation simply cannot pry them apart. No known enzyme can cleave these bonds. No natural process can break them down on any timescale relevant to human civilization. Scientists have started calling PFOA and its chemical relatives "forever chemicals" because, for all practical purposes, they are permanent.

This permanence is exactly what made PFOA so valuable to industry—and so dangerous to everyone else.

A Molecule Designed to Resist Everything

Picture the PFOA molecule as a tadpole. Its head is a carboxylic acid group, the same chemical structure found in vinegar. This head is hydrophilic—it loves water, reaching out to interact with water molecules.

The tail is something else entirely. Seven carbon atoms, each wrapped in fluorine, form a chain that repels absolutely everything. It's hydrophobic, meaning it hates water. But here's what's truly unusual: it's also lipophobic, meaning it hates fats and oils too.

In the natural world, things are usually one or the other. Water-hating molecules typically love oils, and vice versa. That's why oil and water separate—the oil molecules cluster together, fleeing from the water, while water molecules do the same in reverse. But PFOA's fluorinated tail wants nothing to do with either camp. It repels water. It repels oil. It repels almost everything.

This dual rejection makes PFOA extraordinarily useful as a surfactant—a substance that reduces surface tension and helps different materials interact. When you need to mix things that don't want to mix, when you need coatings that repel both water and grease, when you need chemicals that remain stable under extreme conditions, PFOA delivers.

The Rise of an Industrial Workhorse

The Minnesota Mining and Manufacturing Company—better known as 3M—began producing PFOA in 1947. They made it through a process called electrochemical fluorination, essentially zapping octanoic acid (a fatty acid found in coconut oil) with hydrofluoric acid to swap out all the hydrogen atoms for fluorine.

The result was messy. Only about ten to fifteen percent of what came out of the reactor was the pure, straight-chain PFOA they wanted. The rest was a tangle of branched molecules and cyclic byproducts. But even this impure mixture proved remarkably useful.

DuPont became 3M's biggest customer starting in 1951. They used PFOA as a processing aid in manufacturing Teflon, the non-stick coating that would eventually find its way onto billions of cooking pans worldwide. PFOA acted as an emulsifier, helping to polymerize tetrafluoroethylene—the building block of Teflon—in water. Without PFOA, making Teflon was much harder.

But cookware was just the beginning. PFOA spread into an astonishing range of applications. Stain-resistant carpets. Waterproof outdoor clothing. Food packaging. Floor waxes. Firefighting foams. Electrical wire insulation. Semiconductor manufacturing. Anywhere you needed something to resist water, resist oil, resist heat, or resist chemical attack, PFOA and its relatives showed up.

The Bodies Tell the Story

In 1968, researchers made an unsettling discovery. They found fluorine-containing organic compounds in the blood serum of ordinary Americans—people who had never worked in chemical plants, people who had no obvious exposure to industrial fluorochemicals. By 1976, scientists suspected this contamination was PFOA or something very much like it.

This wasn't supposed to happen. Chemicals used in industrial processes aren't supposed to end up inside people.

But PFOA did. It got into food through packaging. It got into water through industrial discharge. It got into air through manufacturing emissions. And once it entered the human body, it stayed there. The half-life of PFOA in human blood—the time it takes for half of the chemical to be eliminated—is roughly two to four years. For a compound that's everywhere in the environment and continuously entering our bodies through multiple routes, this means it accumulates.

By the early 2000s, studies showed that more than 98 percent of Americans had detectable PFOA in their blood. Not just people living near chemical plants. Everyone. The average concentration was about four parts per billion. This might sound tiny, but for a synthetic chemical that serves no biological function, the very presence of any amount in virtually every human being represents something remarkable—and troubling.

A Lawyer Versus a Corporation

The story might have continued quietly if not for a farmer in West Virginia whose cattle started dying.

Earl Tennant owned land near DuPont's Washington Works facility in Parkersburg. His creek ran alongside the plant. In the late 1990s, his cattle began showing bizarre symptoms—stumbling, foaming at the mouth, developing grotesque tumors. Over a hundred and fifty animals died. Tennant filmed the sick and dead cattle, the strange discolored water, the peculiar foam in his creek. He went looking for a lawyer.

He found Robert Bilott.

Bilott was a partner at a prestigious Cincinnati law firm. His specialty was defending chemical companies—he knew the industry inside and out. But something about Tennant's case made him take it on. What he uncovered would consume the next two decades of his career.

In autumn 2000, Bilott won a court order forcing DuPont to share all documentation related to PFOA. What arrived was staggering: 110,000 files containing internal studies, medical reports, and confidential research spanning decades.

The documents revealed a damning timeline. DuPont had known since 1961 that PFOA caused liver problems in animals. By 1993, their own scientists had established that PFOA caused cancerous tumors in the livers, testicles, and pancreases of lab rats. The company had measured PFOA in the blood of its workers and found elevated levels. They had tested the water near their plant and found contamination. They had found PFOA in products sold to consumers.

And they had told no one.

The Scale of Contamination

As Bilott dug deeper, the scope of what DuPont had done became clear. Between 1951 and 2003, the Washington Works plant had released more than 1.7 million pounds of C8 into the environment. The chemical had saturated the local groundwater. It had spread through private wells. An estimated 70,000 people had been drinking PFOA-contaminated water for years.

But here's what made PFOA different from typical industrial pollution: it didn't stay local. Because PFOA is so stable and so mobile, it spread everywhere. Atmospheric emissions from manufacturing plants distributed it globally. The compound migrated through soil into groundwater. It traveled down rivers to the ocean. Scientists found it in the Arctic, in remote Pacific islands, in wildlife that had never come near an industrial facility.

Researchers detected PFOA in the blood of polar bears in Alaska. In sea turtles. In bald eagles. In salmon and swordfish. On Sand Island, a wildlife refuge in the middle of the Pacific Ocean—roughly halfway between North America and Asia—Laysan albatrosses carried PFOA in their bodies.

The chemical was everywhere, in everything, forever.

What PFOA Does to Bodies

After the initial lawsuits, a massive health study was conducted on the affected West Virginia community. Researchers drew blood from nearly 70,000 people who had been drinking PFOA-contaminated water. They tracked health outcomes for years. The results linked PFOA exposure to six diseases: kidney cancer, testicular cancer, thyroid disease, ulcerative colitis, high cholesterol, and pregnancy-induced hypertension.

The International Agency for Research on Cancer—the World Health Organization's cancer research arm—ultimately classified PFOA as carcinogenic to humans. Not "possibly carcinogenic" or "probably carcinogenic," but simply carcinogenic.

Animal studies revealed more. PFOA affected the liver, the immune system, development in fetuses. It persisted in the body long enough to interfere with hormone systems. Its effects were insidious, building up over years of exposure.

And the exposures were essentially unavoidable. PFOA wasn't just in water near chemical plants. It was in non-stick cookware, in fast-food wrappers, in microwave popcorn bags, in waterproof jackets, in stain-resistant upholstery. The very products that made modern life convenient were continuously adding to the burden of forever chemicals in human bodies.

The Long Phase-Out

The United States Environmental Protection Agency (EPA) began pressing the chemical industry on PFOA in the late 1990s, after data emerged about the global distribution of related compounds. In May 2000, 3M announced it would phase out production of PFOA, its sister compound PFOS (perfluorooctanesulfonic acid), and related products. This was an extraordinary decision—these were among 3M's best-selling products.

The company said it would have made the same choice regardless of EPA pressure. Whether or not you believe that, the announcement triggered a scramble. DuPont, suddenly cut off from its primary PFOA supplier, built its own manufacturing plant in Fayetteville, North Carolina, in 2002.

That plant would later become another contamination controversy.

In 2006, the EPA launched what it called the PFOA Stewardship Program. Eight major chemical companies signed on, agreeing to reduce PFOA emissions by 95 percent by 2010 and to work toward eliminating the chemical from products and emissions entirely by 2015. Gore-Tex—the famous waterproof fabric—eliminated PFOA from its manufacturing process in 2013. Non-stick cookware followed.

But phase-outs don't eliminate what's already there. Every molecule of PFOA ever manufactured still exists somewhere in the world—in groundwater, in sediments, in living creatures, in the ocean. The concentrations in American bloodstreams have dropped by about 70 percent since the phase-out began, which sounds encouraging until you remember that this means 30 percent of the original burden remains, and that background exposures continue through environmental contamination.

The Replacements Aren't Much Better

When industry phases out a problematic chemical, it typically introduces alternatives. In the case of PFOA, one of the main replacements was called GenX.

GenX is a shorter molecule—only three carbon atoms in its fluorinated chain compared to PFOA's seven. Industry promoted it as safer because shorter chains are less bioaccumulative. They don't build up in bodies as much because they're eliminated faster.

This is technically true. But a 2015 study found that GenX caused many of the same health problems as PFOA in lab rats. The tumors were still there. The liver damage was still there. It just required higher doses to produce the same effects. And while GenX doesn't persist in the body as long, it's still a forever chemical in the environment—the carbon-fluorine bonds remain unbreakable.

This is the fundamental problem with the entire class of per- and polyfluoroalkyl substances, known collectively as PFAS. There are thousands of these compounds, each with slightly different properties, but all sharing that indestructible fluorinated backbone. Regulating them one at a time means playing an endless game of whack-a-mole: ban one compound, watch industry switch to a similar one, discover years later that the replacement is also harmful, repeat.

The Regulatory Reckoning

In 2024, the EPA finally issued binding drinking water regulations for PFOA and five other PFAS compounds. This was the first time the United States had set enforceable limits on forever chemicals in drinking water—nearly sixty years after DuPont first learned that PFOA caused liver damage in mice.

The new standard for PFOA is four parts per trillion. That's four molecules out of every trillion molecules of water. This limit is extraordinarily stringent, reflecting how harmful even tiny exposures can be.

Achieving this standard will require massive investments in water treatment infrastructure. Many existing filtration systems can't remove PFAS effectively. Communities that discover contamination face difficult choices: install expensive new treatment systems, find alternative water sources, or live with the exposure.

And drinking water is only one pathway. PFAS enter bodies through food, through contact with treated materials, through air. Addressing drinking water contamination is necessary but far from sufficient.

The Persistence Problem

Here is the uncomfortable truth about PFOA and its forever chemical relatives: there is no solution to what has already been released.

We cannot remove PFOA from the ocean. We cannot extract it from groundwater aquifers that stretch across entire regions. We cannot recall it from the bodies of the billions of people and animals who have absorbed it. The molecules that 3M began synthesizing in 1947 are still out there, unchanged, and will remain so for centuries or millennia to come.

What we can do is stop adding more. The phase-outs and regulations that have slowly emerged represent attempts to at least stop making the problem worse. But even this faces resistance. PFAS compounds remain useful. Industries that rely on them argue that alternatives are inadequate, more expensive, or less effective. Some applications—certain types of firefighting foam, for instance—have been slow to transition because the chemical properties of PFAS are genuinely difficult to replicate with safer materials.

This is why famous chefs and others have been fighting proposed PFAS bans. Non-stick coatings in professional kitchens rely on these compounds. Waterproof outdoor gear depends on them. The everyday conveniences of stain-resistant fabrics and grease-proof packaging come from them. Eliminating forever chemicals means accepting trade-offs in performance, or investing heavily in developing alternatives, or simply doing without certain product features.

A Legacy Written in Blood

Robert Bilott received the Right Livelihood Award in 2017 for his work exposing the PFOA contamination scandal. His story was told in the documentary "The Devil We Know" and the Hollywood film "Dark Waters." He became one of the most famous environmental lawyers in American history.

But what he uncovered was not unique to DuPont. 3M had its own secret studies dating back decades. A quiet agreement with the government of Jersey, a British island in the English Channel, reportedly helped the company avoid class-action lawsuits by limiting health testing of residents. When Bilott learned of this arrangement, he was shocked: "I've not seen something like this where there's an agreement to try to help the company against claims by others. Particularly if it's something affecting public health and safety or research."

The pattern is familiar from other industrial contamination scandals: companies discovering harm, burying the evidence, continuing production because profits were too large to sacrifice, fighting regulation at every step. What makes the PFAS story distinctive is the chemical nature of the compounds themselves. Lead paint can be removed. Asbestos can be abated. PCBs eventually break down. But forever chemicals are forever. The contamination DuPont and 3M unleashed cannot be undone.

And it's inside you right now. It's in your blood, at concentrations that can be precisely measured. It came from a factory in Minnesota, or North Carolina, or a dozen other places around the world. It traveled through air and water and food to reach your body, where it will remain for years before you finally eliminate it—only for another dose to arrive from background environmental exposure.

That is the legacy of PFOA: a molecule designed to last forever, produced for sixty years without adequate oversight, distributed across the entire planet, and now present in virtually every human being alive.

Forever is a long time.