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Perfluorooctanoic acid (PFOA;
conjugate base A conjugate acid, within the Brønsted–Lowry acid–base theory, is a chemical compound formed when an acid donates a proton () to a base—in other words, it is a base with a hydrogen ion added to it, as in the reverse reaction it loses a ...
perfluorooctanoate; also known colloquially as C8, for its 8 carbon chain structure) is a
perfluorinated carboxylic acid Perfluoroalkyl carboxylic acids (PFCAs), or perfluorocarboxylic acids are compounds of the formula CnF(2n+1)CO2H that belong to the class of per- and polyfluoroalkyl substances. The simplest example is trifluoroacetic acid. These compounds are o ...
produced and used worldwide as an industrial
surfactant Surfactants are chemical compounds that decrease the surface tension between two liquids, between a gas and a liquid, or interfacial tension between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsifiers, foaming ...
in chemical processes and as a material
feedstock A raw material, also known as a feedstock, unprocessed material, or primary commodity, is a basic material that is used to produce goods, finished goods, energy, or intermediate materials that are feedstock for future finished products. As feedst ...
. PFOA is considered a surfactant, or fluorosurfactant, due to its chemical structure, which consists of a perfluorinated, ''n''-octyl "tail group" and a
carboxylate In organic chemistry, a carboxylate is the conjugate base of a carboxylic acid, (or ). It is an ion with negative charge. Carboxylate salts are salts that have the general formula , where M is a metal and ''n'' is 1, 2,...; ''carboxylat ...
"head group". The head group can be described as
hydrophilic A hydrophile is a molecule or other molecular entity that is attracted to water molecules and tends to be dissolved by water.Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon'' Oxford: Clarendon Press. In contrast, hydrophobes are no ...
while the
fluorocarbon Fluorocarbons are chemical compounds with carbon-fluorine bonds. Compounds that contain many C-F bonds often has distinctive properties, e.g., enhanced stability, volatility, and hydrophobicity. Fluorocarbons and their derivatives are commerci ...
tail is both
hydrophobic In chemistry, hydrophobicity is the physical property of a molecule that is seemingly repelled from a mass of water (known as a hydrophobe). In contrast, hydrophiles are attracted to water. Hydrophobic molecules tend to be nonpolar and, th ...
and
lipophobic Lipophobicity, also sometimes called lipophobia (from the Greek λιποφοβία from λίπος ''lipos'' "fat" and φόβος ''phobos'' "fear"), is a chemical property of chemical compounds which means " fat rejection", literally "fear of fat". ...
. The tail group is inert and does not interact strongly with polar or non-polar chemical moieties; the head group is reactive and interacts strongly with polar groups, specifically water. The "tail" is hydrophobic due to being
non-polar In chemistry, polarity is a separation of electric charge leading to a molecule or its chemical groups having an electric dipole moment, with a negatively charged end and a positively charged end. Polar molecules must contain one or more pola ...
and lipophobic because fluorocarbons are less susceptible to the
London dispersion force London dispersion forces (LDF, also known as dispersion forces, London forces, instantaneous dipole–induced dipole forces, fluctuating induced dipole bonds or loosely as van der Waals forces) are a type of intermolecular force acting between at ...
than
hydrocarbon In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and hydrophobic, and their odors are usually weak or ex ...
s. PFOA is one of many synthetic
organofluorine Organofluorine chemistry describes the chemistry of the organofluorines, organic compounds that contain the carbon–fluorine bond. Organofluorine compounds find diverse applications ranging from oil and water repellents to pharmaceuticals, ref ...
compounds collectively known as
per- and polyfluoroalkyl substances Per- and polyfluoroalkyl substances (PFASs) are synthetic organofluorine chemical compounds that have multiple fluorine atoms attached to an alkyl chain. An early definition, from 2011, required that they contain at least one perfluoroalkyl mo ...
(PFASs). PFOA is used in several industrial applications, including carpeting, upholstery, apparel, floor wax, textiles, fire fighting foam and sealants. PFOA serves as a surfactant in the
emulsion polymerization Emulsion polymerization is a type of radical polymerization that usually starts with an emulsion incorporating water, monomer, and surfactant. The most common type of emulsion polymerization is an oil-in-water emulsion, in which droplets of monomer ...
of
fluoropolymers A fluoropolymer is a fluorocarbon-based polymer with multiple carbon–fluorine bonds. It is characterized by a high resistance to solvents, acids, and bases. The best known fluoropolymer is polytetrafluoroethylene under the brand name "Teflon, ...
and as a building block for the synthesis of perfluoroalkyl-substituted compounds, polymers, and polymeric materials. PFOA has been manufactured since the 1940s in industrial quantities. It is also formed by the
degradation Degradation may refer to: Science * Degradation (geology), lowering of a fluvial surface by erosion * Degradation (telecommunications), of an electronic signal * Biodegradation of organic substances by living organisms * Environmental degradatio ...
of precursors such as some
fluorotelomer Fluorotelomers are fluorocarbon-based oligomers, or telomers, synthesized by telomerization. Some fluorotelomers and fluorotelomer-based compounds are a source of environmentally persistent perfluorinated carboxylic acids such as PFOA and PFNA, wh ...
s. PFOA is used as a surfactant because it can lower the
surface tension Surface tension is the tendency of liquid surfaces at rest to shrink into the minimum surface area possible. Surface tension is what allows objects with a higher density than water such as razor blades and insects (e.g. water striders) to f ...
of water more than
hydrocarbon In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and hydrophobic, and their odors are usually weak or ex ...
surfactants while having exceptional stability due to having perfluoroalkyl tail group. The stability of PFOA is desired industrially but is a cause of concern environmentally. A study of workers living near a
DuPont DuPont de Nemours, Inc., commonly shortened to DuPont, is an American multinational chemical company first formed in 1802 by French-American chemist and industrialist Éleuthère Irénée du Pont de Nemours. The company played a major role in ...
Teflon Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene that has numerous applications. It is one of the best-known and widely applied PFAS. The commonly known brand name of PTFE-based composition is Teflon by Chemou ...
plant found an association between PFOA exposure and two kinds of cancer as well as four other diseases. A positive exposure-response trend for kidney cancer is supported by many studies. PFOA has been detected in the blood of more than 98% of the general US population in the low and sub-
parts per billion In science and engineering, the parts-per notation is a set of pseudo-units to describe small values of miscellaneous dimensionless quantities, e.g. mole fraction or mass fraction. Since these fractions are quantity-per-quantity measures, they ...
(ppb) range, and levels are higher in chemical plant employees and surrounding subpopulations. How general populations are exposed to PFOA is not completely understood. PFOA has been detected in industrial waste, stain-resistant carpets, carpet-cleaning liquids,
house dust Dust is made of fine particles of solid matter. On Earth, it generally consists of particles in the atmosphere that come from various sources such as soil lifted by wind (an aeolian process), volcanic eruptions, and pollution. Dust in homes ...
, microwave popcorn bags, water, food, and Teflon (
PTFE Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene that has numerous applications. It is one of the best-known and widely applied PFAS. The commonly known brand name of PTFE-based composition is Teflon by Chemour ...
) products. As a result of a class-action lawsuit and community settlement with
DuPont DuPont de Nemours, Inc., commonly shortened to DuPont, is an American multinational chemical company first formed in 1802 by French-American chemist and industrialist Éleuthère Irénée du Pont de Nemours. The company played a major role in ...
, three
epidemiologists Epidemiology is the study and analysis of the distribution (who, when, and where), patterns and determinants of health and disease conditions in a defined population. It is a cornerstone of public health, and shapes policy decisions and evidenc ...
conducted studies on the population surrounding a chemical plant that was exposed to PFOA at levels greater than in the general population. Studies have found correlation between high PFOA exposure and six health outcomes:
kidney cancer Kidney cancer, also known as renal cancer, is a group of cancers that starts in the kidney. Symptoms may include blood in the urine, lump in the abdomen, or back pain. Fever, weight loss, and tiredness may also occur. Complications can include spr ...
,
testicular cancer Testicular cancer is cancer that develops in the testicles, a part of the male reproductive system. Symptoms may include a lump in the testicle, or swelling or pain in the scrotum. Treatment may result in infertility. Risk factors include an u ...
,
ulcerative colitis Ulcerative colitis (UC) is a long-term condition that results in inflammation and ulcers of the colon and rectum. The primary symptoms of active disease are abdominal pain and diarrhea mixed with blood (hematochezia). Weight loss, fever, and a ...
,
thyroid disease Thyroid disease is a medical condition that affects the function of the thyroid gland. The thyroid gland is located at the front of the neck and produces thyroid hormones that travel through the blood to help regulate many other organs, meaning t ...
,
hypercholesterolemia Hypercholesterolemia, also called high cholesterol, is the presence of high levels of cholesterol in the blood. It is a form of hyperlipidemia (high levels of lipids in the blood), hyperlipoproteinemia (high levels of lipoproteins in the blood), ...
(high cholesterol), and
pregnancy-induced hypertension Gestational hypertension or pregnancy-induced hypertension (PIH) is the development of new hypertension in a pregnant woman after 20 weeks' gestation without the presence of protein in the urine or other signs of pre-eclampsia. Gestational hyperte ...
. The primary manufacturer of
PFOS Perfluorooctanesulfonic acid (PFOS) (conjugate base perfluorooctanesulfonate) is a chemical compound having an eight-carbon fluorocarbon chain and a sulfonic acid functional group and thus a perfluorosulfonic acid. It is an anthropogenic (man ...
, the
3M Company 3M (originally the Minnesota Mining and Manufacturing Company) is an American multinational conglomerate operating in the fields of industry, worker safety, U.S. health care, and consumer goods. The company produces over 60,000 products under ...
(known as Minnesota Mining and Manufacturing Company from 1902 to 2002), began a production phase-out in 2002 in response to concerns expressed by the
United States Environmental Protection Agency The Environmental Protection Agency (EPA) is an independent executive agency of the United States federal government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it be ...
(EPA). Eight other companies agreed to gradually phase out the manufacturing of the chemical by 2015. By 2014, EPA had listed PFOA and perfluorooctanesulfonates (
salts In chemistry, a salt is a chemical compound consisting of an ionic assembly of positively charged cations and negatively charged anions, which results in a compound with no net electric charge. A common example is table salt, with positively cha ...
of
perfluorooctanesulfonic acid Perfluorooctanesulfonic acid (PFOS) (conjugate base perfluorooctanesulfonate) is a chemical compound having an eight-carbon fluorocarbon chain and a sulfonic acid functional group and thus a perfluorosulfonic acid. It is an anthropogenic (man-ma ...
, PFOS) as emergent contaminants:


History

3M (then the Minnesota Mining and Manufacturing Company) began producing PFOA by
electrochemical fluorination Electrochemical fluorination (ECF), or electrofluorination, is a foundational organofluorine chemistry method for the preparation of fluorocarbon-based organofluorine compounds.G. Siegemund, W. Schwertfeger, A. Feiring, B. Smart, F. Behr, H. Voge ...
in 1947. Starting in 1951, DuPont purchased PFOA from 3M for use in the manufacturing of specific
fluoropolymers A fluoropolymer is a fluorocarbon-based polymer with multiple carbon–fluorine bonds. It is characterized by a high resistance to solvents, acids, and bases. The best known fluoropolymer is polytetrafluoroethylene under the brand name "Teflon, ...
—commercially branded as Teflon, but DuPont internally referred to the material as C8. In 1968,
organofluorine Organofluorine chemistry describes the chemistry of the organofluorines, organic compounds that contain the carbon–fluorine bond. Organofluorine compounds find diverse applications ranging from oil and water repellents to pharmaceuticals, ref ...
content was detected in the
blood serum Serum () is the fluid and solute component of blood which does not play a role in clotting. It may be defined as blood plasma without the clotting factors, or as blood with all cells and clotting factors removed. Serum includes all proteins not u ...
of consumers, and in 1976 it was suggested to be PFOA or a related compound such as
PFOS Perfluorooctanesulfonic acid (PFOS) (conjugate base perfluorooctanesulfonate) is a chemical compound having an eight-carbon fluorocarbon chain and a sulfonic acid functional group and thus a perfluorosulfonic acid. It is an anthropogenic (man ...
. In 1999, EPA ordered companies to examine the effects of perfluorinated chemicals after receiving data on the global distribution and toxicity of PFOS. For these reasons, and EPA pressure, in May 2000, 3M announced the phaseout of the production of PFOA, PFOS, and PFOS-related products—the company's best-selling repellent. 3M stated that they would have made the same decision regardless of EPA pressure. Because of the 3M phaseout, in 2002, DuPont built its own plant in
Fayetteville, North Carolina Fayetteville () is a city in and the county seat of Cumberland County, North Carolina, United States. It is best known as the home of Fort Bragg, a major U.S. Army installation northwest of the city. Fayetteville has received the All-America C ...
, to manufacture the chemical. The chemical has received attention due to litigation from the PFOA-contaminated community around DuPont's Washington Works facility in
Washington, West Virginia Washington is a census-designated place (CDP) in Wood County, West Virginia, United States, situated along the Ohio River. It is part of the Parkersburg-Marietta-Vienna, WV- OH Metropolitan Statistical Area. The population was 1,175 at the 2010 ce ...
, along with EPA focus. In 2004,
ChemRisk ChemRisk is a Delaware Limited Liability Company, a for-profit scientific consulting firm headquartered in San Francisco, California that is part of Cardno ChemRisk. ChemRisk founder and former president, Dennis Paustenbach, "has long been an expert ...
—an "industry risk assessor" that had been contracted by Dupont, reported that over 1.7 million pounds of C8 had been "dumped, poured and released" into the environment from Dupont's Parkersburg, West Virginia-based Washington Works plant between 1951 and 2003. Research on PFOA has demonstrated ubiquity, animal-based toxicity, and some associations with human health parameters and potential health effects. Additionally, advances in
analytical chemistry Analytical chemistry studies and uses instruments and methods to separate, identify, and quantify matter. In practice, separation, identification or quantification may constitute the entire analysis or be combined with another method. Separati ...
in recent years have allowed the routine detection of low- and sub-
parts per billion In science and engineering, the parts-per notation is a set of pseudo-units to describe small values of miscellaneous dimensionless quantities, e.g. mole fraction or mass fraction. Since these fractions are quantity-per-quantity measures, they ...
levels of PFOA in a variety of substances. In 2013,
Gore-Tex Gore-Tex is a waterproof, breathable fabric membrane and registered trademark of W. L. Gore & Associates. Invented in 1969, Gore-Tex can repel liquid water while allowing water vapor to pass through and is designed to be a lightweight, waterpr ...
eliminated the use of PFOAs in the manufacture of its weatherproof functional fabrics. Major companies producing PFOA signed with the Global PFOA Stewardship Program with the goal of elimination of PFOA by 2015. Since then it has been eliminated from the production of non-stick materials used in cookware.
GenX The General Electric GEnx ("General Electric Next-generation") is an advanced dual rotor, axial flow, high-bypass turbofan jet engine in production by GE Aviation for the Boeing 787 and 747-8. The GEnx is intended to succeed the CF6 in GE's pro ...
has been introduced as a replacement for PFOA, but in a 2015 study which tested the effects on rats, GenX caused many of the same health problems as PFOA, but required much higher concentrations. This is because GenX (C3) is a short chain alternative to PFOA. GenX also has a significantly shorter half-life than PFOA so it is not as bio-persistent as PFOA or other long chain perfluorinated chemicals.


Robert Bilott investigation

In the fall of 2000, lawyer
Robert Bilott Robert Bilott (born August 2, 1965) is an American environmental attorney from Cincinnati, Ohio. Bilott is known for the lawsuits against DuPont on behalf of plaintiffs injured by waste dumped in rural communities in West Virginia. Bilott has spe ...
, a partner at
Taft Stettinius & Hollister Taft Stettinius & Hollister, commonly known as "Taft", is an American, white-shoe law firm founded in Cincinnati, with offices in Cleveland, Columbus, Dayton and Delaware, Ohio; Chicago, Illinois; Denver, Colorado; Detroit, Michigan; Indianapoli ...
, won a court order forcing DuPont to share all documentation related to PFOA. This included 110,000 files, consisting of confidential studies and reports conducted by DuPont scientists over decades. By 1993, DuPont understood that "PFOA caused cancerous testicular, pancreatic and liver tumors in lab animals" and the company began to investigate alternatives. However, because products manufactured with PFOA were such an integral part of DuPont's earnings, $1 billion in annual profit, they chose to continue using PFOA. Bilott learned that both "3M and DuPont had been conducting secret medical studies on PFOA for more than four decades", and by 1961 DuPont was aware of
hepatomegaly Hepatomegaly is the condition of having an enlarged liver. It is a non-specific medical sign having many causes, which can broadly be broken down into infection, hepatic tumours, or metabolic disorder. Often, hepatomegaly will present as an abdomi ...
in mice fed with PFOA. Later research eventually found that PFOA had an outsized effect based on gender on several negative health outcomes in mice that had been exposed to the chemical. The PFOA exposure in these mice led to a modification of genetic expression. This led to the development of fatty tissue which caused the exposed mice to develop varying rates of
hypercholesterolemia Hypercholesterolemia, also called high cholesterol, is the presence of high levels of cholesterol in the blood. It is a form of hyperlipidemia (high levels of lipids in the blood), hyperlipoproteinemia (high levels of lipoproteins in the blood), ...
(high cholesterol). The impact of PFOA on this health outcome varied greatly between mice of different
genotypes The genotype of an organism is its complete set of genetic material. Genotype can also be used to refer to the alleles or variants an individual carries in a particular gene or genetic location. The number of alleles an individual can have in a ...
across relevant parts of the genome. Also, notably, female mice across all genotypes saw significantly higher rates and more severe cases of hypercholesterolemia. Bilott exposed how DuPont had been knowingly polluting water with PFOAs in
Parkersburg, West Virginia Parkersburg is a city in and the county seat of Wood County, West Virginia, Wood County, West Virginia. Located at the confluence of the Ohio River, Ohio and Little Kanawha River, Little Kanawha rivers, it is the state's fourth-largest city and ...
, since the 1980s. In the 1980s and 1990s, researchers investigated the
toxicity Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a subst ...
of PFOA. For his work in the exposure of the contamination, lawyer Robert Bilott has received several awards including The Right Livelihood Award in 2017. This battle with DuPont is featured in the documentary ''
The Devil We Know ''The Devil We Know'' is a 2018 investigative documentary film by director Stephanie Soechtig regarding allegations of health hazards from perfluorooctanoic acid (PFOA, also known as C8), a key ingredient used in manufacturing Teflon, and DuPont ...
'', which premiered at the
Sundance Film Festival The Sundance Film Festival (formerly Utah/US Film Festival, then US Film and Video Festival) is an annual film festival organized by the Sundance Institute. It is the largest independent film festival in the United States, with more than 46,66 ...
in 2018, and '' Dark Waters'', directed by
Todd Haynes Todd Haynes (; born January 2, 1961) is an American film director, screenwriter, and producer. His films span four decades with themes examining the personalities of well-known musicians, dysfunctional and dystopian societies, and blurred gender ...
.


Synthesis

PFOA has two main synthesis routes,
electrochemical fluorination Electrochemical fluorination (ECF), or electrofluorination, is a foundational organofluorine chemistry method for the preparation of fluorocarbon-based organofluorine compounds.G. Siegemund, W. Schwertfeger, A. Feiring, B. Smart, F. Behr, H. Voge ...
(ECF) and
telomerization Telomerization is a reaction that produces a particular kind of oligomer with two distinct end groups. The oligomer is called a telomer. Some telomerizations proceed by radical pathways, many do not. A generic equation is: : A-B + n M -> A-M_ ...
. The ECF route sees octanoyl chloride (the
acid chloride In organic chemistry, an acyl chloride (or acid chloride) is an organic compound with the functional group . Their formula is usually written , where R is a side chain. They are reactive derivatives of carboxylic acids (). A specific example o ...
of
octanoic acid Caprylic acid (), also known under the systematic name octanoic acid or C8 Acid, is a saturated fatty acid, medium-chain fatty acid (MCFA). It has the structural formula , and is a colorless oily liquid that is minimally soluble in water with a s ...
) reacted with
hydrofluoric acid Hydrofluoric acid is a Solution (chemistry), solution of hydrogen fluoride (HF) in water. Solutions of HF are colourless, acidic and highly Corrosive substance, corrosive. It is used to make most fluorine-containing compounds; examples include th ...
. Multiple products are formed by ECF with the target acid fluoride F(CF2)7COF being produced as only 10–15% of the yield, while the main products are perfluorinated cyclic
ether In organic chemistry, ethers are a class of compounds that contain an ether group—an oxygen atom connected to two alkyl or aryl groups. They have the general formula , where R and R′ represent the alkyl or aryl groups. Ethers can again be c ...
isomer In chemistry, isomers are molecules or polyatomic ions with identical molecular formulae – that is, same number of atoms of each element – but distinct arrangements of atoms in space. Isomerism is existence or possibility of isomers. Iso ...
s, including
FC-75 FC-75 is a fluorocarbon derivative of tetrahydrofuran with the chemical formula C8F16O. It is practically insoluble in water. It is one of the 3M Fluorinert fluids. It is used as an inert coolant fluid in electronics and other applications, and ...
. This acid fluoride is hydrolyzed to yield PFOA as a mixture of straight-chain (78%), terminally branched (13%), and internally branched (9%) molecules, because ECF induces rearrangements the carbon tail of the acid chloride. ECF also results in production wastes. 3M synthesized ECF PFOA at their
Cottage Grove, Minnesota Cottage Grove is a city south of Saint Paul, Minnesota, Saint Paul in Washington County, Minnesota, Washington County in the U.S. state, State of Minnesota. It lies on the north bank of the Mississippi River, north of the confluence with the St ...
facility from 1947 to 2002 and was the world's largest producer. ECF production continues on a smaller scale in Europe and Asia. PFOA is also synthesized by the
telomerization Telomerization is a reaction that produces a particular kind of oligomer with two distinct end groups. The oligomer is called a telomer. Some telomerizations proceed by radical pathways, many do not. A generic equation is: : A-B + n M -> A-M_ ...
represented below, where the telogen is the
organoiodine compound Organoiodine compounds are organic compounds that contain one or more carbon–iodine bonds. They occur widely in organic chemistry, but are relatively rare in nature. The thyroxine hormones are organoiodine compounds that are required for he ...
and the taxogen is the
tetrafluoroethylene Tetrafluoroethylene (TFE) is a fluorocarbon with the chemical formula C2 F4. It is the simplest perfluorinated alkene. This gaseous species is used primarily in the industrial preparation of fluoropolymers. Properties Tetrafluoroethylene is a ...
. Each step is an
addition reaction In organic chemistry, an addition reaction is, in simplest terms, an organic reaction where two or more molecules combine to form a larger one (the adduct).. Addition reactions are limited to chemical compounds that have multiple bonds, such as ...
where the carbon-iodine bond of the telogen is added across the carbon-carbon double bond of the unsaturated taxogen, resulting in the formation of a new telogen. :CF3CF2I + F2C=CF2 → CF3CF2CF2CF2I :CF3(CF2)3I + F2C=CF2 → CF3(CF2)5I :CF3(CF2)5I + F2C=CF2 → CF3(CF2)7I The product is
oxidized Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a d ...
by SO3 to form PFOA. Since each addition produces a new teleomer,
fluorotelomer Fluorotelomers are fluorocarbon-based oligomers, or telomers, synthesized by telomerization. Some fluorotelomers and fluorotelomer-based compounds are a source of environmentally persistent perfluorinated carboxylic acids such as PFOA and PFNA, wh ...
s like these form with varying length chains containing an even number of carbon atoms, depending on reaction conditions. Typically, most products within will contain between two and six taxogens (that is, from CF3(CF2)5I to CF3(CF2)13I). After oxidation,
distillation Distillation, or classical distillation, is the process of separation process, separating the components or substances from a liquid mixture by using selective boiling and condensation, usually inside an apparatus known as a still. Dry distilla ...
is used to separate PFOA from the other perfluorinated carboxylic acids. The telomerization synthesis of PFOA was pioneered by
DuPont DuPont de Nemours, Inc., commonly shortened to DuPont, is an American multinational chemical company first formed in 1802 by French-American chemist and industrialist Éleuthère Irénée du Pont de Nemours. The company played a major role in ...
, and is not well suited to the laboratory. PFOA formed by telomerization is completely linear, in contrast to the mixture of structures formed by ECF.


Applications

PFOA has widespread applications. In 1976, PFOA was reported as a water and oil repellent "in fabrics and leather and in the production of floor waxes and
waxed paper Waxed paper (also wax paper, waxpaper, or paraffin paper) is paper that has been made moisture-proof and grease-proof through the application of wax. The practice of oiling parchment or paper in order to make it semi-translucent or moisture-pro ...
s"; however, it is believed that paper is no longer treated with
perfluorinated compounds A perfluorinated compound (PFC) or perfluoro compound is an organofluorine compound containing only carbon-fluorines and C−C bonds, as well as potentially heteroatoms. Perfluorinated compounds have properties that result from the presence of fl ...
, but with
fluorotelomer Fluorotelomers are fluorocarbon-based oligomers, or telomers, synthesized by telomerization. Some fluorotelomers and fluorotelomer-based compounds are a source of environmentally persistent perfluorinated carboxylic acids such as PFOA and PFNA, wh ...
s with less than 0.1% PFOA. The compound is also used in "
insulators Insulator may refer to: * Insulator (electricity), a substance that resists electricity ** Pin insulator, a device that isolates a wire from a physical support such as a pin on a utility pole ** Strain insulator, a device that is designed to work ...
for electric wires, planar etching of
fused silica Fused quartz, fused silica or quartz glass is a glass consisting of almost pure silica (silicon dioxide, SiO2) in amorphous (non-crystalline) form. This differs from all other commercial glasses in which other ingredients are added which change ...
",
fire fighting foam Firefighting foam is a foam used for fire suppression. Its role is to cool the fire and to coat the fuel, preventing its contact with oxygen, thus achieving suppression of the combustion. Firefighting foam was invented by the Russian engineer and ...
, and outdoor clothing. As a protonated species, the acid form of PFOA was the most widely used perfluorocarboxylic acid used as a reactive intermediate in the production of fluoroacrylic esters. As a
salt Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quantitie ...
, its dominant use is as an
emulsifier An emulsion is a mixture of two or more liquids that are normally immiscible (unmixable or unblendable) owing to liquid-liquid phase separation. Emulsions are part of a more general class of two-phase systems of matter called colloids. Altho ...
for the
emulsion polymerization Emulsion polymerization is a type of radical polymerization that usually starts with an emulsion incorporating water, monomer, and surfactant. The most common type of emulsion polymerization is an oil-in-water emulsion, in which droplets of monomer ...
of fluoropolymers such as PTFE,
polyvinylidene fluoride Polyvinylidene fluoride or polyvinylidene difluoride (PVDF) is a highly non-reactive thermoplastic fluoropolymer produced by the polymerization of vinylidene difluoride. PVDF is a specialty plastic used in applications requiring the highest pur ...
, and
fluoroelastomer {{refimprove, date=June 2008 A fluoroelastomer is a fluorocarbon-based synthetic rubber. Fluroelastomers generally have wide chemical resistance. Composition Several compositions of fluoroelastomers exist including FKM (by ASTM D1418 standard, equi ...
s. For this use, 3M subsidiary Dyneon has a replacement emulsifer despite DuPont stating PFOA is an "essential processing aid". In the past PFOA was used in the production of
Gore-Tex Gore-Tex is a waterproof, breathable fabric membrane and registered trademark of W. L. Gore & Associates. Invented in 1969, Gore-Tex can repel liquid water while allowing water vapor to pass through and is designed to be a lightweight, waterpr ...
as it is PTFE-based. In PTFE processing, PFOA is in
aqueous solution An aqueous solution is a solution in which the solvent is water. It is mostly shown in chemical equations by appending (aq) to the relevant chemical formula. For example, a solution of table salt, or sodium chloride (NaCl), in water would be re ...
and forms
micelle A micelle () or micella () (plural micelles or micellae, respectively) is an aggregate (or supramolecular assembly) of surfactant amphipathic lipid molecules dispersed in a liquid, forming a colloidal suspension (also known as associated collo ...
s that contain
tetrafluoroethylene Tetrafluoroethylene (TFE) is a fluorocarbon with the chemical formula C2 F4. It is the simplest perfluorinated alkene. This gaseous species is used primarily in the industrial preparation of fluoropolymers. Properties Tetrafluoroethylene is a ...
and the growing
polymer A polymer (; Greek '' poly-'', "many" + ''-mer'', "part") is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic a ...
. PFOA can be used to stabilize fluoropolymer and fluoroelastomer suspensions before further industrial processing and in
ion-pair In chemistry, ion association is a chemical reaction whereby ions of opposite electric charge come together in solution to form a distinct chemical entity. Ion associates are classified, according to the number of ions that associate with each ot ...
reversed-phase liquid chromatography it can act as an extraction agent. PFOA also finds uses in electronic products and as an industrial
fluorosurfactant Per- and polyfluoroalkyl substances (PFASs) are synthetic organofluorine chemical compounds that have multiple fluorine atoms attached to an alkyl chain. An early definition, from 2011, required that they contain at least one perfluoroalkyl mo ...
. In a 2009 EPA study of 116 products, purchased between March 2007 and May 2008 and found to contain at least 0.01% fluorine by weight, the concentrations of PFOA were determined. Concentrations shown below range from not detected, or ND, (with the
detection limit The limit of detection (LOD or LoD) is the lowest signal, or the lowest corresponding quantity to be determined (or extracted) from the signal, that can be observed with a sufficient degree of confidence or statistical significance. However, the ...
in parenthesis) to 6750 with concentrations in
nanogram To help compare different orders of magnitude, the following lists describe various mass levels between 10−59  kg and 1052 kg. The least massive thing listed here is a graviton, and the most massive thing is the observable universe. ...
s of PFOA per
gram The gram (originally gramme; SI unit symbol g) is a Physical unit, unit of mass in the International System of Units (SI) equal to one one thousandth of a kilogram. Originally defined as of 1795 as "the absolute weight of a volume of pure wate ...
of sample (
parts per billion In science and engineering, the parts-per notation is a set of pseudo-units to describe small values of miscellaneous dimensionless quantities, e.g. mole fraction or mass fraction. Since these fractions are quantity-per-quantity measures, they ...
) unless stated otherwise.


Global occurrence and sources

PFOA contaminates every
continent A continent is any of several large landmasses. Generally identified by convention rather than any strict criteria, up to seven geographical regions are commonly regarded as continents. Ordered from largest in area to smallest, these seven ...
. Two of the most common types (PFOS and PFOA) were phased out of production in the United States (US) in 2002 and 2015 respectively, but are still present in some imported products. PFOA and PFOS are found in every American person's blood stream in the parts per billion range, though those concentrations have decreased by 70% for PFOA and 84% for PFOS between 1999 and 2014, which coincides with the end of the production and phase out of PFOA and PFOS in the US. PFOA has been detected in the central Pacific Ocean at low parts per quadrillion ranges, and at low
parts per trillion In science and engineering, the parts-per notation is a set of pseudo-units to describe small values of miscellaneous dimensionless quantities, e.g. mole fraction or mass fraction. Since these fractions are quantity-per-quantity measures, they ...
(ppt) levels in
coastal waters The coast, also known as the coastline or seashore, is defined as the area where land meets the ocean, or as a line that forms the boundary between the land and the coastline. The Earth has around of coastline. Coasts are important zones in n ...
. Due to the surfactant nature of PFOA, it has been found to concentrate in the top layers of ocean water. PFOA is detected widely in
surface water Surface water is water located on top of land forming terrestrial (inland) waterbodies, and may also be referred to as ''blue water'', opposed to the seawater and waterbodies like the ocean. The vast majority of surface water is produced by prec ...
s, and is present in numerous mammals, fish, and bird species. PFOA is in the blood or vital organs of Atlantic salmon, swordfish, striped mullet, gray seals, common cormorants, Alaskan polar bears, brown pelicans, sea turtles, sea eagles, Midwestern bald eagles, California sea lions and Laysan albatrosses on Sand Island, a wildlife refuge on Midway Atoll, in the middle of the North Pacific Ocean, about halfway between North America and Asia. Because PFAS are ubiquitous in households, consumer products, food, and the environment generally, some trace levels reflecting this ubiquitous broad use of these compounds will make their way into the
wastewater Wastewater is water generated after the use of freshwater, raw water, drinking water or saline water in a variety of deliberate applications or processes. Another definition of wastewater is "Used water from any combination of domestic, industr ...
and
solid waste Municipal solid waste (MSW), commonly known as trash or garbage in the United States and rubbish in Britain, is a waste type consisting of everyday items that are discarded by the public. "Garbage" can also refer specifically to food waste, ...
streams.https://casaweb.org/wp-content/uploads/2020/01/National-PFAS-Receivers-Factsheet.pdf However, wildlife has much less PFOA than humans, unlike
PFOS Perfluorooctanesulfonic acid (PFOS) (conjugate base perfluorooctanesulfonate) is a chemical compound having an eight-carbon fluorocarbon chain and a sulfonic acid functional group and thus a perfluorosulfonic acid. It is an anthropogenic (man ...
and other longer
perfluorinated carboxylic acid Perfluoroalkyl carboxylic acids (PFCAs), or perfluorocarboxylic acids are compounds of the formula CnF(2n+1)CO2H that belong to the class of per- and polyfluoroalkyl substances. The simplest example is trifluoroacetic acid. These compounds are o ...
s; in wildlife, PFOA is not as bioaccumulative as longer perfluorinated carboxylic acids. Municipal wastewater and
landfill A landfill site, also known as a tip, dump, rubbish dump, garbage dump, or dumping ground, is a site for the disposal of waste materials. Landfill is the oldest and most common form of waste disposal, although the systematic burial of the waste ...
leachate A leachate is any liquid that, in the course of passing through matter, extracts soluble or suspended solids, or any other component of the material through which it has passed. Leachate is a widely used term in the environmental sciences wher ...
s are considered as important sources of PFOA to the environment, Most industrialized nations have average PFOA
blood serum Serum () is the fluid and solute component of blood which does not play a role in clotting. It may be defined as blood plasma without the clotting factors, or as blood with all cells and clotting factors removed. Serum includes all proteins not u ...
levels ranging from 2 to 8
parts per billion In science and engineering, the parts-per notation is a set of pseudo-units to describe small values of miscellaneous dimensionless quantities, e.g. mole fraction or mass fraction. Since these fractions are quantity-per-quantity measures, they ...
; the highest consumer sub-population identified was in Korea—with about 60
parts per billion In science and engineering, the parts-per notation is a set of pseudo-units to describe small values of miscellaneous dimensionless quantities, e.g. mole fraction or mass fraction. Since these fractions are quantity-per-quantity measures, they ...
. In
Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = Seal (emblem), National seal , national_motto = "Fi ...
,
Vietnam Vietnam or Viet Nam ( vi, Việt Nam, ), officially the Socialist Republic of Vietnam,., group="n" is a country in Southeast Asia, at the eastern edge of mainland Southeast Asia, with an area of and population of 96 million, making i ...
, and
Afghanistan Afghanistan, officially the Islamic Emirate of Afghanistan,; prs, امارت اسلامی افغانستان is a landlocked country located at the crossroads of Central Asia and South Asia. Referred to as the Heart of Asia, it is bordere ...
blood serum levels have been recorded to be below one part per billion. In 2003–2004 99.7% of Americans had detectable PFOA in their serum with an average of about 4 parts per billion, and concentrations of PFOA in US serum have declined by 25% in recent years. Despite a decrease in PFOA, the longer perfluorinated carboxylic acid
PFNA Perfluorononanoic acid, or PFNA, is a synthetic perfluorinated carboxylic acid and fluorosurfactant that is also an environmental contaminant found in people and wildlife along with PFOS and PFOA. Chemistry and properties In acidic form it is a ...
is increasing in the blood of US consumers. PFAS are also found in paper mill residuals, digestates, composts, and soils. Given the ubiquity of PFAS, and the comparative background levels which may be found in wastewater, biosolids, and leachates, setting requirements near analytical detection limits on these sources may not provide a discernable benefit to protecting public health.


Industrial sources

PFOA is released directly from industrial sites. For example, the estimate for the DuPont Washington Works facility is a total PFOA emissions of 80,000 pounds ( lbs) in 2000 and 1,700 pounds in 2004. A 2006 study, with two of four authors being DuPont employees, estimated about 80% of historical perfluorocarboxylate emissions were released to the environment from
fluoropolymer A fluoropolymer is a fluorocarbon-based polymer with multiple carbon–fluorine bonds. It is characterized by a high resistance to solvents, acids, and bases. The best known fluoropolymer is polytetrafluoroethylene under the brand name "Teflon ...
manufacture and use. PFOA can be measured in water from industrial sites other than fluorochemical plants. PFOA has also been detected in emissions from the carpet industry, paper and electronics industries. The most important emission sources are carpet and textile protection products, as well as fire-fighting foams.


Precursors

PFOA can form as a breakdown product from a variety of precursor molecules. In fact, the main products of the fluorotelomer industry, fluorotelomer-based polymers, have been shown to degrade to form PFOA and related compounds, with half-lives of decades, both biotically and by simple abiotic reaction with water. It has been argued that fluorotelomer-based polymers already produced might be major sources of PFOA globally for decades to come. Other precursors that degrade to PFOA include 8:2
fluorotelomer alcohol Fluorotelomer alcohols, or FTOHs, are fluorotelomers with an alcohol functional group. They are volatile precursors to perfluorinated carboxylic acids, such as PFOA and PFNA, and other compounds. Naming Commonly, an individual fluorotelomer alco ...
(F(CF2)8CH2CH2OH), polyfluoroalkyl phosphate surfactants (PAPS), and possibly ''N''-EtFOSE alcohol (F(CF2)8SO2N(Et)CH2CH2OH). When PTFE (Teflon) is degraded by heat (
pyrolysis The pyrolysis (or devolatilization) process is the thermal decomposition of materials at elevated temperatures, often in an inert atmosphere. It involves a change of chemical composition. The word is coined from the Greek-derived elements ''py ...
) it can form PFOA as a minor product. The
Organisation for Economic Co-operation and Development The Organisation for Economic Co-operation and Development (OECD; french: Organisation de coopération et de développement économiques, ''OCDE'') is an intergovernmental organization, intergovernmental organisation with 38 member countries ...
(OECD) has compiled a list of 615 chemicals that have the potential to break down into perfluorocarboxylic acids (PFCA) including PFOA. However, not all 615 have the potential to break down to form PFOA. A majority of
waste water treatment plants Sewage treatment (or domestic wastewater treatment, municipal wastewater treatment) is a type of wastewater treatment which aims to remove contaminants from sewage to produce an effluent that is suitable for discharge to the surrounding envir ...
(WWTPs) that have been tested output more PFOA than is input, and this increased output has been attributed to the biodegradation of fluorotelomer alcohols. A current PFOA precursor concern are
fluorotelomer Fluorotelomers are fluorocarbon-based oligomers, or telomers, synthesized by telomerization. Some fluorotelomers and fluorotelomer-based compounds are a source of environmentally persistent perfluorinated carboxylic acids such as PFOA and PFNA, wh ...
-based polymers; fluorotelomer alcohols attached to hydrocarbon backbones via
ester In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides ar ...
linkages may detach and be free to biodegrade to PFOA.


Sources to people

Food Food is any substance consumed by an organism for nutritional support. Food is usually of plant, animal, or fungal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals. The substance is inge ...
,
drinking water Drinking water is water that is used in drink or food preparation; potable water is water that is safe to be used as drinking water. The amount of drinking water required to maintain good health varies, and depends on physical activity level, a ...
, outdoor
air The atmosphere of Earth is the layer of gases, known collectively as air, retained by Earth's gravity that surrounds the planet and forms its planetary atmosphere. The atmosphere of Earth protects life on Earth by creating pressure allowing f ...
, indoor air,
dust Dust is made of fine particles of solid matter. On Earth, it generally consists of particles in the atmosphere that come from various sources such as soil lifted by wind (an aeolian process), volcanic eruptions, and pollution. Dust in homes ...
, and
food packaging Food packaging is a packaging system specifically designed for food and represents one of the most important aspects among the processes involved in the food industry, as it provides protection from chemical, biological and physical alterations ...
s are all implicated as sources of PFOA to people. However, it is unclear which exposure routes dominate because of data gaps. When water is a source, blood levels are approximately 100 times higher than drinking water levels. People who lived in the PFOA-contaminated area around DuPont's Washington Works facility were found to have higher levels of PFOA in their blood from drinking water. The highest PFOA levels in drinking water were found in the Little Hocking water system, with an average concentration of 3.55 parts per billion during 2002–2005. Individuals who drank more tap water, ate locally grown fruits and vegetables, or ate local meat, were all associated with having higher PFOA levels. Residents who used water
carbon filter Carbon filtering is a method of filtering that uses a bed of activated carbon to remove impurities from a fluid using adsorption. Mechanism Carbon filtering works by adsorption, in which pollutants in the fluid to be treated are trapped inside th ...
systems had lower PFOA levels.


Food contact surfaces

PFOA is also formed as an unintended byproduct in the production of
fluorotelomer Fluorotelomers are fluorocarbon-based oligomers, or telomers, synthesized by telomerization. Some fluorotelomers and fluorotelomer-based compounds are a source of environmentally persistent perfluorinated carboxylic acids such as PFOA and PFNA, wh ...
s and is present in finished goods treated with fluorotelomers, including those intended for food contact. Fluorotelomers are applied to food contact papers because they are
lipophobic Lipophobicity, also sometimes called lipophobia (from the Greek λιποφοβία from λίπος ''lipos'' "fat" and φόβος ''phobos'' "fear"), is a chemical property of chemical compounds which means " fat rejection", literally "fear of fat". ...
: they prevent oil from soaking into the paper from fatty foods. Also, fluorotelomers can be
metabolized Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cell ...
into PFOA. In a
U.S. Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a federal agency of the Department of Health and Human Services. The FDA is responsible for protecting and promoting public health through the control and supervision of food ...
(USFDA) study,
lipophobic Lipophobicity, also sometimes called lipophobia (from the Greek λιποφοβία from λίπος ''lipos'' "fat" and φόβος ''phobos'' "fear"), is a chemical property of chemical compounds which means " fat rejection", literally "fear of fat". ...
fluorotelomer-based paper coatings (which can be applied to food contact paper in the concentration range of 0.4%) were found to contain 88,000–160,000 parts per billion PFOA before application, while the oil from microwave popcorn bags contained 6–290 parts per billion PFOA after heating. Toxicologists estimate that microwave popcorn could account for about 20% of the PFOA levels measured in an individual consuming 10 bags a year if 1% of the fluorotelomers are metabolized to PFOA. In 2008 as news stories began to raise concerns about PFOA in microwaved popcorn, Dan Turner, DuPont's global public relations chief, said, "I serve microwave popcorn to my three-year-old." Five years later, journalist
Peter Laufer Peter David Laufer is an independent American journalist, broadcaster and documentary filmmaker working in traditional and new media. He is the James Wallace Chair in Journalism at the University of Oregon School of Journalism and Communication. ...
wrote to Turner to ask if his child was still eating microwave popcorn. "I am not going to comment on such a personal inquiry", Turner replied. Fluorotelomer coatings are used in fast food wrappers, candy wrappers, and pizza box liners. PAPS, a type of paper fluorotelomer coating, and PFOA precursor, is also used in food contact papers. Despite DuPont's asserting that "cookware coated with DuPont Teflon non-stick coatings does not contain PFOA", residual PFOA was also detected in finished
PTFE Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene that has numerous applications. It is one of the best-known and widely applied PFAS. The commonly known brand name of PTFE-based composition is Teflon by Chemour ...
products including PTFE cookware (4–75 parts per billion). However, PFOA levels ranged from undetectable (<1.5) to 4.3 parts per billion in a more recent study. Also, non-stick cookware is heated—which should volatilize PFOA; PTFE products that are not heated, such as PTFE sealant tape, had higher (1800 parts per billion) levels detected. Overall, PTFE cookware is considered an insignificant exposure pathway to PFOA.


Potential path: sludge to food

PFOA and
PFOS Perfluorooctanesulfonic acid (PFOS) (conjugate base perfluorooctanesulfonate) is a chemical compound having an eight-carbon fluorocarbon chain and a sulfonic acid functional group and thus a perfluorosulfonic acid. It is an anthropogenic (man ...
were detected in "very high" (low
parts per million In science and engineering, the parts-per notation is a set of pseudo-units to describe small values of miscellaneous dimensionless quantities, e.g. mole fraction or mass fraction. Since these fractions are quantity-per-quantity measures, they ...
) levels in agricultural fields for grazing beef cattle and crops around
Decatur, Alabama Decatur (dɪˈkeɪtə(r)) is the largest city and county seat of Morgan County (with a portion also in Limestone County) in the U.S. state of Alabama. Nicknamed "The River City", it is located in northern Alabama on the banks of Wheeler Lake ...
. The approximately 5000
acre The acre is a unit of land area used in the imperial Imperial is that which relates to an empire, emperor, or imperialism. Imperial or The Imperial may also refer to: Places United States * Imperial, California * Imperial, Missouri * Imp ...
s of land were fertilized with "treated municipal sewage
sludge Sludge is a semi-solid slurry that can be produced from a range of industrial processes, from water treatment, wastewater treatment or on-site sanitation systems. For example, it can be produced as a settled suspension obtained from conventiona ...
, or
biosolids Biosolids are solid organic matter recovered from a sewage treatment process and used as fertilizer. In the past, it was common for farmers to use animal manure to improve their soil fertility. In the 1920s, the farming community began also to use ...
". PFOA was also detected in fodder grass grown in these soils and the blood of the cattle feeding on this grass. The water treatment plant received process wastewater from a nearby
perfluorochemical A perfluorinated compound (PFC) or perfluoro compound is an Organofluorine chemistry, organofluorine compound containing only Carbon–fluorine bond, carbon-fluorines and C−C bonds, as well as potentially heteroatoms. Perfluorinated compounds hav ...
manufacturing plant. 3M says they managed their own wastes, but Daikin America "discharged process wastewater to the municipal waste treatment plant". If traced to meat, it would be the first time perfluorochemicals were traced from sludge to food. However, the
USDA The United States Department of Agriculture (USDA) is the federal executive department responsible for developing and executing federal laws related to farming, forestry, rural economic development, and food. It aims to meet the needs of com ...
reported—with a detection limits of 20 parts per billion—non-detectable levels for both PFOA and PFOS in cattle muscle tissue.


Household dust

PFOA is frequently found in household dust, making it an important exposure route for adults, but more substantially, children. Children have higher exposures to PFOA through dust compared to adults. Hand-to-mouth contact and proximity to high concentrations of dust make them more susceptible to ingestion, and increases PFOA exposure. One study showed significant positive associations were recognized between dust ingestion and PFOA serum concentrations. However, an alternate study found exposure due to dust ingestion was associated with minimal risk.


Regulatory status


Drinking water and products

In the United States there are no federal drinking water standards for PFOA or PFOS as of early 2021. EPA began requiring
public water system Public water system is a regulatory term used in the United States and Canada, referring to certain utilities and organizations providing drinking water. United States The US Safe Drinking Water Act and derivative legislation define "public water ...
s to monitor for PFOA and PFOS in 2012, and published drinking water health advisories, which are non-regulatory technical documents, in 2016. The lifetime health advisories and health effects support documents assist federal, state, tribal, and local officials and managers of drinking water systems in protecting public health when these chemicals are present in drinking water. The levels of PFOS and PFOA concentrations under which adverse health effects are not anticipated to occur over a lifetime of exposure are 0.07 ppb (70 ppt). In March 2021 EPA announced that it would develop a National Primary Drinking Water Regulation for these contaminants.EPA (2021-03-03). "Announcement of Final Regulatory Determinations for Contaminants on the Fourth Drinking Water Contaminant Candidate List." ''Federal Register,'' The
State of New Jersey New Jersey is a state in the Mid-Atlantic and Northeastern regions of the United States. It is bordered on the north and east by the state of New York; on the east, southeast, and south by the Atlantic Ocean; on the west by the Delaware Ri ...
published drinking water standards for PFOA and PFOS in 2020. A standard for PFNA was published in 2018. This was the first state to publish PFAS standards in the absence of federal regulations. ''See'' U.S. state government actions. In 2018 the
State of New York New York, officially the State of New York, is a state in the Northeastern United States. It is often called New York State to distinguish it from its largest city, New York City. With a total area of , New York is the 27th-largest U.S. state ...
adopted drinking water standards of 10 ppt for PFOA and 10 ppt for PFOS, the most stringent such standards in the United States. The standards apply to
public water system Public water system is a regulatory term used in the United States and Canada, referring to certain utilities and organizations providing drinking water. United States The US Safe Drinking Water Act and derivative legislation define "public water ...
s and took effect in 2019 after a public comment period. Using information gained through a
Freedom of Information Act Freedom of Information Act may refer to the following legislations in different jurisdictions which mandate the national government to disclose certain data to the general public upon request: * Freedom of Information Act 1982, the Australian act * ...
request, in May 2018 it was learned that January 2018 emails between the
EPA The Environmental Protection Agency (EPA) is an independent executive agency of the United States federal government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it be ...
, the
Office of Management and Budget The Office of Management and Budget (OMB) is the largest office within the Executive Office of the President of the United States (EOP). OMB's most prominent function is to produce the president's budget, but it also examines agency programs, pol ...
, the
Department of Defense Department of Defence or Department of Defense may refer to: Current departments of defence * Department of Defence (Australia) * Department of National Defence (Canada) * Department of Defence (Ireland) * Department of National Defense (Philipp ...
, and the
Department of Health and Human Services The United States Department of Health and Human Services (HHS) is a cabinet-level executive branch department of the U.S. federal government created to protect the health of all Americans and providing essential human services. Its motto is " ...
showed an effort to suppress the release of a draft report on the toxicology of PFOS and PFOA done by the
Agency for Toxic Substances and Disease Registry The Agency for Toxic Substances and Disease Registry (ATSDR) is a federal public health agency within the United States Department of Health and Human Services. The agency focuses on minimizing human health risks associated with exposure to haza ...
. The report found that these chemicals endanger human health at a far lower level than EPA has previously called safe. After media accounts of the effort surfaced, the regional EPA administrator for Colorado denied that EPA had anything to do with suppressing the report. The report was finally released on June 21, 2018. The new ATSDR analysis derives provisional Minimal Risk Levels (MRLs) of 3x10−6 mg/kg/day for PFOA and 2x10−6 mg/kg/day for PFOS during intermediate exposure. The European Food Safety Authority opinion sets a provisional tolerable weekly intake (TWI) of 6 x10−6 mg/kg body weight per week for PFOA.


California and food packaging

An attempt to regulate PFOA in food packaging occurred in the US state of California in 2008. A bill, sponsored by State Senator Ellen Corbett and the
Environmental Working Group The Environmental Working Group (EWG) is an American activist group that specializes in research and advocacy in the areas of agricultural subsidies, toxic chemicals, drinking water pollutants, and corporate accountability. EWG is a nonprofit ...
, was passed in the house and senate that would have banned PFOA,
PFOS Perfluorooctanesulfonic acid (PFOS) (conjugate base perfluorooctanesulfonate) is a chemical compound having an eight-carbon fluorocarbon chain and a sulfonic acid functional group and thus a perfluorosulfonic acid. It is an anthropogenic (man ...
, and seven or more related fluorinated carbon compounds in food packaging starting in 2010, but the bill was vetoed by Governor Schwarzenegger. The bill would have affected fluorochemical manufacturers outside of the state. Schwarzenegger said the compound should be reviewed by the newly established, and more comprehensive, state program.


Fluorotelomers

Fluorotelomer Fluorotelomers are fluorocarbon-based oligomers, or telomers, synthesized by telomerization. Some fluorotelomers and fluorotelomer-based compounds are a source of environmentally persistent perfluorinated carboxylic acids such as PFOA and PFNA, wh ...
-based products have been shown to degrade to PFOA over periods of decades; these studies could lead EPA to require DuPont and others to reformulate products with a value over $1 billion.


Health concerns


Toxicology data

PFOA is a possible
carcinogen A carcinogen is any substance, radionuclide, or radiation that promotes carcinogenesis (the formation of cancer). This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes. Several radioactive substan ...
, a possible liver toxicant, a possible developmental toxicant, and a possible
immune system The immune system is a network of biological processes that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to parasitic worms, as well as cancer cells and objects such as wood splinte ...
toxicant, and also exerts
hormonal A hormone (from the Greek participle , "setting in motion") is a class of signaling molecules in multicellular organisms that are sent to distant organs by complex biological processes to regulate physiology and behavior. Hormones are required fo ...
effects including alteration of
thyroid hormone File:Thyroid_system.svg, upright=1.5, The thyroid system of the thyroid hormones T3 and T4 rect 376 268 820 433 Thyroid-stimulating hormone rect 411 200 849 266 Thyrotropin-releasing hormone rect 297 168 502 200 Hypothalamus rect 66 216 386 25 ...
levels at very high concentrations Animal studies show developmental toxicity from reduced birth size, physical developmental delays,
endocrine disruption Endocrine disruptors, sometimes also referred to as hormonally active agents, endocrine disrupting chemicals, or endocrine disrupting compounds are chemicals that can interfere with endocrine (or hormonal) systems. These disruptions can cause c ...
, and
neonatal mortality Perinatal mortality (PNM) refers to the death of a fetus or neonate and is the basis to calculate the perinatal mortality rate. Variations in the precise definition of the perinatal mortality exist, specifically concerning the issue of inclusion o ...
. PFOA alters
lipid metabolism Lipid metabolism is the synthesis and degradation of lipids in cells, involving the breakdown or storage of fats for energy and the synthesis of structural and functional lipids, such as those involved in the construction of cell membranes. In anim ...
. It is an
agonist An agonist is a chemical that activates a receptor to produce a biological response. Receptors are cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an antagonist blocks the action of the ago ...
of
PPARα Peroxisome proliferator-activated receptor alpha (PPAR-α), also known as NR1C1 (nuclear receptor subfamily 1, group C, member 1), is a nuclear receptor protein functioning as a transcription factor that in humans is encoded by the ''PPARA'' gen ...
and is a
peroxisome A peroxisome () is a membrane-bound organelle, a type of microbody, found in the cytoplasm of virtually all eukaryotic cells. Peroxisomes are oxidative organelles. Frequently, molecular oxygen serves as a co-substrate, from which hydrogen pero ...
proliferator in
rodent Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are na ...
s contributing to a well understood form of
oxidative stress Oxidative stress reflects an imbalance between the systemic manifestation of reactive oxygen species and a biological system's ability to readily Detoxification, detoxify the reactive intermediates or to repair the resulting damage. Disturbances ...
. Humans are considered less susceptible to
peroxisome A peroxisome () is a membrane-bound organelle, a type of microbody, found in the cytoplasm of virtually all eukaryotic cells. Peroxisomes are oxidative organelles. Frequently, molecular oxygen serves as a co-substrate, from which hydrogen pero ...
proliferation than rodents. However, PFOA has been found to be a liver carcinogen in
rainbow trout The rainbow trout (''Oncorhynchus mykiss'') is a species of trout native to cold-water tributaries of the Pacific Ocean in Asia and North America. The steelhead (sometimes called "steelhead trout") is an anadromous (sea-run) form of the coasta ...
via a potential
estrogenic Estrogen or oestrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal activ ...
mechanism, which may be more relevant to humans. PFOA has been described as a member of a group of "classic non-genotoxic carcinogens". However, a provisional German assessment notes that a 2005 study found PFOA to be
genotoxic Genotoxicity is the property of chemical agents that damage the genetic information within a cell causing mutations, which may lead to cancer. While genotoxicity is often confused with Mutagen, mutagenicity, all mutagens are genotoxic, but some geno ...
via a peroxisome proliferation pathway that produced
oxygen radicals In chemistry, a radical, also known as a free radical, is an atom, molecule, or ion that has at least one unpaired valence electron. With some exceptions, these unpaired electrons make radicals highly chemically reactive. Many radicals spont ...
in HepG2 cells, and a 2006 study demonstrated the induction and suppression of a broad range of
gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...
s; therefore, it states that the indirect
genotoxic Genotoxicity is the property of chemical agents that damage the genetic information within a cell causing mutations, which may lead to cancer. While genotoxicity is often confused with Mutagen, mutagenicity, all mutagens are genotoxic, but some geno ...
(and thus carcinogenic) potential of PFOA ''cannot'' be dismissed. An additional study has shown PFOA to be developmentally toxic, hepatotoxic, immunotoxic, and to have negative effects of thyroid hormone production. Criteria have been proposed that would allow PFOA, and other perfluorinated compounds, to be classified as "weakly non-specific
genotoxic Genotoxicity is the property of chemical agents that damage the genetic information within a cell causing mutations, which may lead to cancer. While genotoxicity is often confused with Mutagen, mutagenicity, all mutagens are genotoxic, but some geno ...
".


Endocrine disruption of sexual steroids

In 2018, an in vitro toxicology study analyzed the disruptor effect of PFOS and PFOA on porcine ovarian cell
steroidogenesis A steroid is a biologically active organic compound with four rings arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes that alter membrane fluidity; and a ...
. Specifically, the study focused on secretion in porcine
theca In biology, a theca (plural thecae) is a sheath or a covering. Botany In botany, the theca is related to plant's flower anatomy. The theca of an angiosperm consists of a pair of microsporangia that are adjacent to each other and share a commo ...
and
granulosa cell A granulosa cell or follicular cell is a somatic cell of the sex cord that is closely associated with the developing female gamete (called an oocyte or egg) in the ovary of mammals. Structure and function In the primordial ovarian follicle, an ...
s, controlling
gonadotropic Gonadotropins are glycoprotein hormones secreted by gonadotropic cells of the anterior pituitary of vertebrates. This family includes the mammalian hormones follicle-stimulating hormone (FSH) and luteinizing hormone (LH), the placental/chorio ...
stimulation. Five ovaries were obtained and dissected to collect theca and granulosa cells. The experimental design included: evaluation of PFOS and PFOA on basal steroid secretion, stimulation of LH on theca cells and FSH on granulosa cells, effect of PFOS and PFOA on
steroidogenesis A steroid is a biologically active organic compound with four rings arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes that alter membrane fluidity; and a ...
in the stimulated cells, quantification of
steroid hormone A steroid hormone is a steroid that acts as a hormone. Steroid hormones can be grouped into two classes: corticosteroids (typically made in the adrenal cortex, hence ''cortico-'') and sex steroids (typically made in the gonads or placenta). Wi ...
s by
chemiluminescence Chemiluminescence (also chemoluminescence) is the emission of light (luminescence) as the result of a chemical reaction. There may also be limited emission of heat. Given reactants A and B, with an excited intermediate ◊, : + -> lozenge -> ...
,
protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
content determination,
statistical analysis Statistical inference is the process of using data analysis to infer properties of an underlying distribution of probability.Upton, G., Cook, I. (2008) ''Oxford Dictionary of Statistics'', OUP. . Inferential statistical analysis infers propertie ...
. The treatment groups had 9 data points each, from which the mean and standard deviation were calculated. The control group had 15 data points. A multi-factor analysis of variance (
ANOVA Analysis of variance (ANOVA) is a collection of statistical models and their associated estimation procedures (such as the "variation" among and between groups) used to analyze the differences among means. ANOVA was developed by the statistician ...
) and Tukey's test were used for the concentrations of P4, A4 and E2. The two groups were compared using a Student's "t", with statistical significance set at p < 0.05. Results show the disruptor effect of PFOS and PFOA depends on cell type. PFOS and PFOA inhibit the secretion of steroid hormones in both theca cells and granulosa cells with gonadotropic stimulus. In cells without gonadotropic stimulus, PFOS inhibit theca cells but not granulosa, while PFOA inhibit granulosa cells but not theca. These differences are explained by the different types of PPARs in cell type. The study used concentrations below the range found in human blood circulation, suggesting that this may occur in human population. These results indicated PFOS and PFOA act as endocrine disruptors on ovarian cells which could affect subsequent sexual steroids.


Human data

PFOA is resistant to degradation by natural processes such as
metabolism Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cell ...
,
hydrolysis Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution reaction, substitution, elimination reaction, elimination, and solvation reactions in which water ...
,
photolysis Photodissociation, photolysis, photodecomposition, or photofragmentation is a chemical reaction in which molecules of a chemical compound are broken down by photons. It is defined as the interaction of one or more photons with one target molecule. ...
, or
biodegradation Biodegradation is the breakdown of organic matter by microorganisms, such as bacteria and fungi. It is generally assumed to be a natural process, which differentiates it from composting. Composting is a human-driven process in which biodegrada ...
and has been found to persist in the environment. PFOA is found in environmental and biological fluids as the anion perfluorooctanoate. PFOA can be absorbed from ingestion and can penetrate
skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other cuticle, animal coverings, such as the arthropod exoskeleton, have diffe ...
. The acid headgroup of PFOA enables binding to
protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
s with
fatty acid In chemistry, particularly in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, fr ...
or
hormone A hormone (from the Greek participle , "setting in motion") is a class of signaling molecules in multicellular organisms that are sent to distant organs by complex biological processes to regulate physiology and behavior. Hormones are required ...
substrates such as
serum albumin Serum albumin, often referred to simply as blood albumin, is an albumin (a type of globular protein) found in vertebrate blood. Human serum albumin is encoded by the ''ALB'' gene. Other mammalian forms, such as bovine serum albumin, are chemical ...
, liver fatty acid-binding protein, and the
nuclear receptor In the field of molecular biology, nuclear receptors are a class of proteins responsible for sensing steroids, thyroid hormones, vitamins, and certain other molecules. These receptors work with other proteins to regulate the expression of speci ...
s
PPARα Peroxisome proliferator-activated receptor alpha (PPAR-α), also known as NR1C1 (nuclear receptor subfamily 1, group C, member 1), is a nuclear receptor protein functioning as a transcription factor that in humans is encoded by the ''PPARA'' gen ...
and possibly
CAR A car or automobile is a motor vehicle with wheels. Most definitions of ''cars'' say that they run primarily on roads, seat one to eight people, have four wheels, and mainly transport people instead of goods. The year 1886 is regarded as ...
. In animals, PFOA is mainly present in the
liver The liver is a major Organ (anatomy), organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of proteins and biochemicals necessary for ...
,
blood Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the c ...
, and
kidney The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; blood ...
s. PFOA does not accumulate in
fat tissue Adipose tissue, body fat, or simply fat is a loose connective tissue composed mostly of adipocytes. In addition to adipocytes, adipose tissue contains the stromal vascular fraction (SVF) of cells including preadipocytes, fibroblasts, vascular en ...
, unlike traditional
organohalogen Halocarbon compounds are chemicals in which one or more carbon atoms are linked by covalent bonds with one or more halogen atoms (fluorine, chlorine, bromine or iodine – ) resulting in the formation of organofluorine compounds, organochlorin ...
persistent organic pollutant Persistent organic pollutants (POPs), sometimes known as "forever chemicals", are organic compounds that are resistant to environmental degradation through chemical, biological, and photolytic processes. They are toxic chemicals that adversely ...
s. In humans, PFOA has an average
elimination half-life Biological half-life (also known as elimination half-life, pharmacologic half-life) is the time taken for concentration of a biological substance (such as a medication) to decrease from its maximum concentration ( Cmax) to half of Cmax in the bl ...
of about three years. Because of this long half-life, PFOA has the potential to
bioaccumulate Bioaccumulation is the gradual accumulation of substances, such as pesticides or other chemicals, in an organism. Bioaccumulation occurs when an organism absorbs a substance at a rate faster than that at which the substance is lost or eliminated ...
. The levels of PFOA exposure in humans vary widely. While an average American might have 3 or 4
parts per billion In science and engineering, the parts-per notation is a set of pseudo-units to describe small values of miscellaneous dimensionless quantities, e.g. mole fraction or mass fraction. Since these fractions are quantity-per-quantity measures, they ...
of PFOA present in their blood serum, individuals occupationally exposed to PFOA have had blood serum levels over 100,000 parts per billion (100
parts per million In science and engineering, the parts-per notation is a set of pseudo-units to describe small values of miscellaneous dimensionless quantities, e.g. mole fraction or mass fraction. Since these fractions are quantity-per-quantity measures, they ...
or 0.01%) recorded. In a study of individuals living around DuPont's Washington Works plant, those who had no occupational exposure had a
median In statistics and probability theory, the median is the value separating the higher half from the lower half of a data sample, a population, or a probability distribution. For a data set, it may be thought of as "the middle" value. The basic fe ...
blood serum level of 329 parts per billion while the median of those with occupational exposure was 775 parts per billion. While no amount of PFOA in humans is legally recognized as harmful, DuPont was "not satisfied" with data showing their Chinese workers accumulated an average of about 2,250 parts per billion of PFOA in their blood from a starting average of around 50 parts per billion less than a year prior. In late 2012, scientists at
Emory University Emory University is a private research university in Atlanta, Georgia. Founded in 1836 as "Emory College" by the Methodist Episcopal Church and named in honor of Methodist bishop John Emory, Emory is the second-oldest private institution of ...
compared health risks in workers at a DuPont chemical plant in West Virginia with high PFOA exposure to the risks of the same diseases in other regional DuPont factory workers and in the US population. In comparison with the other DuPont workers, workers at the high-PFOA plant were at roughly three times the risk of dying of
mesothelioma Mesothelioma is a type of cancer that develops from the thin layer of tissue that covers many of the internal organs (known as the mesothelium). The most common area affected is the lining of the lungs and chest wall. Less commonly the lining ...
or chronic kidney disease, and roughly twice the risk of dying of
diabetes mellitus Diabetes, also known as diabetes mellitus, is a group of metabolic disorders characterized by a high blood sugar level ( hyperglycemia) over a prolonged period of time. Symptoms often include frequent urination, increased thirst and increased ap ...
. Workers were at similarly elevated risk for kidney cancer and for non-cancer kidney diseases. In rodents, PFOA concentrates in the kidneys.


Consumers

Single
cross-sectional studies In medical research, social science, and biology, a cross-sectional study (also known as a cross-sectional analysis, transverse study, prevalence study) is a type of observational study that analyzes data from a population, or a representative su ...
on consumers have been published noting multiple associations. Blood serum levels of PFOA were associated with an increased time to pregnancy—or "
infertility Infertility is the inability of a person, animal or plant to reproduce by natural means. It is usually not the natural state of a healthy adult, except notably among certain eusocial species (mostly haplodiploid insects). It is the normal state ...
"—in a 2009 study. PFOA exposure was associated with decreased
semen quality Semen quality is a measure of male fertility, a measure of the ability of sperm in semen to accomplish fertilization. Semen quality involves both sperm quantity and quality Cryptorchidism, hypospadias, testicular cancer and poor semen quality ma ...
, increased serum
alanine aminotransferase Alanine transaminase (ALT) is a transaminase enzyme (). It is also called alanine aminotransferase (ALT or ALAT) and was formerly called serum glutamate-pyruvate transaminase or serum glutamic-pyruvic transaminase (SGPT) and was first character ...
levels, and increased occurrence of
thyroid disease Thyroid disease is a medical condition that affects the function of the thyroid gland. The thyroid gland is located at the front of the neck and produces thyroid hormones that travel through the blood to help regulate many other organs, meaning t ...
. In a study of 2003–2004 US samples, a higher (9.8 milligram per
deciliter The litre (international spelling) or liter (American English spelling) (SI symbols L and l, other symbol used: ℓ) is a metric unit of volume. It is equal to 1 cubic decimetre (dm3), 1000 cubic centimetres (cm3) or 0.001 cubic metre (m3). ...
) total cholesterol level was observed when the highest
quartile In statistics, a quartile is a type of quantile which divides the number of data points into four parts, or ''quarters'', of more-or-less equal size. The data must be ordered from smallest to largest to compute quartiles; as such, quartiles are a ...
was compared to the lowest. Along with other related compounds, PFOA exposure was associated with an increased risk of
attention deficit hyperactivity disorder Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterised by excessive amounts of inattention, hyperactivity, and impulsivity that are pervasive, impairing in multiple contexts, and otherwise age-inap ...
(ADHD) in a study of US children aged 12–15. In a paper presented at the 2009 annual meeting of the International Society of Environmental Epidemiology, PFOA appeared to act as an
endocrine disruptor Endocrine disruptors, sometimes also referred to as hormonally active agents, endocrine disrupting chemicals, or endocrine disrupting compounds are chemicals that can interfere with endocrine (or hormonal) systems. These disruptions can cause c ...
by a potential mechanism on
breast The breast is one of two prominences located on the upper ventral region of a primate's torso. Both females and males develop breasts from the same embryological tissues. In females, it serves as the mammary gland, which produces and secret ...
maturation in young girls. A C8 Science Panel status report noted an association between exposure in girls and a later onset of
puberty Puberty is the process of physical changes through which a child's body matures into an adult body capable of sexual reproduction. It is initiated by hormonal signals from the brain to the gonads: the ovaries in a girl, the testes in a boy. ...
. PFOA exposure and incident cancer research Extensive research on PFOA and its role in the causal pathway of cancers exists for animals, however human studies are rare—most studies are mortality studies, which have small sample sizes.  A longitudinal study focused on residents living in Mid-Ohio Valley concluded that PFOA concentrations are positively associated with kidney and testicular cancers azard ratio = 1.10 and 1.34, respectively, for a 1-unit increase in log-transformed serum PFOA The study consisted of 32,254 residents with 2,507 reported cancer diagnoses occurring during study period. PFOA serum concentrations were measured at baseline and three to six year follow-up meetings. Retrospective yearly PFOA serum levels were estimated for each subject from 1952 through 2011. Initial subject recruitment was performed using eligibility criteria and surveys—subjects were eligible if they lived or worked in one of the six contaminated water districts for at least one year between 1950 and December 3, 2004. Follow-up surveys were administered and remaining subjects (completion of at least one survey) were then included in the analysis dataset—selection bias was assessed and the final subjects did not differ significantly from the original population. Retrospective PFOA serum concentrations were calculated using the published method of Shin et al. 2011a, 2011b). Historical regional data including emission rates by the DuPont facility, temporal patterns and groundwater flow are incorporated in the model as well as individual specific occupational exposure level was included. A job-exposure matrix was developed to assess estimated PFOA levels for workers across times and job roles. Incident data was self-reported by study participants and followed up with a medical chart review. Cancer diagnoses were verified using Ohio/West Virginia cancer registries. A proportional hazards regression model was used for each cancer type with the cancer as the outcome and PFOA serum level included as a time-varying covariate. Participants were followed from age 20 (or age in 1952) to the age of cancer diagnosis. Models were adjusted for time-varying- smoking and alcohol consumption, as well as sex, education and five-year birth cohort. The outcome of PFOA serum level was log-transformed due to the scarcity of very high cumulative exposure values. Participants who worked at the DuPont facility had higher PFOA serum levels and higher estimated annual PFOA levels than subjects who never worked at the facility. After cancer diagnosis validation, thyroid, kidney and testicular cancer risk were found to increase with an increase in the PFOA serum concentration (log-transformed), with testicular cancer being significantly associated (α =0.05). The results are consistent with previous mortality analyses performed using DuPont data. There is a positive exposure-response trend for cancer incidence and PFOA serum levels. Kidney and testicular cancer are of interest given that animal studies have found that PFOA is distributed mainly in the kidneys and because PFOA has been found to induce testicular tumors in rats. Impact of in utero exposure on reproductive organs Due to the fact that PFOA is able to readily pass through the placental barrier, exposure is of particular concern during in utero development. Numerous studies have analyzed the impacts of PFOA on fetal development of reproductive organs. One study that followed a Danish pregnancy cohort suggests that in utero exposure to PFOA could be associated with lower levels of sperm concentration and total sperm count in adult males, reduced testicular size, and higher adjusted levels of luteinizing hormone and follicle-stimulating hormone. In utero PFOA exposure is also demonstrated to impact female development. For example, a study following a Danish population-based cohort found a 5.3 month later age of menarche in girls exposed to higher levels of PFOA in utero. Delayed onset of menarche is associated with lower bone mineral density and may have psychosocial impacts. Other impacts on exposure in utero PFOA exposure on thyroid function has also been a topic of concern, and has found to negatively impact thyroid stimulating hormone even at low levels when exposed during fetal development. PFOA is also shown to have obesogenic effects, and an experimental study found a positive correlation to low-dose prenatal exposure of PFOA and prevalence of overweight and high waist circumference in females at age 20. A correlation between in utero PFOA exposure and mental performance has yet to be established, as many studies have resulted in insignificant results. For example, a study conducted near Parkersburg, West Virginia did not find a significant association between in utero PFOA exposure and performance of math skills or reading performance in children ages 6 to 12 living in the PFOA-contaminated water district. Based on a cohort study conducted in the Mid-Ohio Valley, no clear association was found between prenatal exposure to PFOA and birth defects, although a possible association with brain defects was observed and requires further research and assessment. PFOA has been associated with signs of reduced fetal growth including lower birth weight. However, other studies have not replicated the lower birth weight finding including a study on the DuPont exposed community. Extrapolated epidemiological data suggests a slight association between PFOA exposure and low birth weight. This was consistent based on blood levels of PFOA metabolites regardless of the geographic residence of subjects. Generally, the findings among human fetuses exposed to the chemical were considerably less drastic than what was seen in mice studies. Because of this, studies linking exposure to low birth weight can be considered inconclusive. PFOA exposure in the Danish general population was not associated with an increased risk of
prostate The prostate is both an Male accessory gland, accessory gland of the male reproductive system and a muscle-driven mechanical switch between urination and ejaculation. It is found only in some mammals. It differs between species anatomically, ...
,
bladder The urinary bladder, or simply bladder, is a hollow organ in humans and other vertebrates that stores urine from the kidneys before disposal by urination. In humans the bladder is a distensible organ that sits on the pelvic floor. Urine enters ...
,
pancreatic The pancreas is an Organ (anatomy), organ of the digestive system and endocrine system of vertebrates. In humans, it is located in the abdominal cavity, abdomen behind the stomach and functions as a gland. The pancreas is a mixed or heterocrine ...
, or
liver cancer Liver cancer (also known as hepatic cancer, primary hepatic cancer, or primary hepatic malignancy) is cancer that starts in the liver. Liver cancer can be primary (starts in liver) or secondary (meaning cancer which has spread from elsewhere to th ...
. Maternal PFOA levels were not associated with an offspring's increased risk of hospitalization due to infectious diseases, behavioral and motor coordination problems, or delays in reaching developmental milestones.


Employees and DuPont exposed community

In 2010, the three members of the C8 Science Panel published a
review A review is an evaluation of a publication, product, service, or company or a critical take on current affairs in literature, politics or culture. In addition to a critical evaluation, the review's author may assign the work a content rating, ...
of the
epidemiological Epidemiology is the study and analysis of the distribution (who, when, and where), patterns and determinants of health and disease conditions in a defined population. It is a cornerstone of public health, and shapes policy decisions and evidenc ...
evidence on PFOA exposure in ''
Environmental Health Perspectives ''Environmental Health Perspectives'' (''EHP'') is a peer-reviewed Peer review is the evaluation of work by one or more people with similar competencies as the producers of the work (peers). It functions as a form of self-regulation by qua ...
''. Insufficient evidence exists to conclude PFOA causes adverse health effects in humans, but consistent evidence exists on associations with higher cholesterol and uric acid. Whether or not these potential effects result in an increase in
cardiovascular disease Cardiovascular disease (CVD) is a class of diseases that involve the heart or blood vessels. CVD includes coronary artery diseases (CAD) such as angina and myocardial infarction (commonly known as a heart attack). Other CVDs include stroke, h ...
is unknown. Further data on the 69,030 member cohort that is being studied by the panel is scheduled for release through 2012. A 2011 epidemiological study demonstrated "probable link" between PFOA and kidney cancer, testicular cancer, thyroid disease, high cholesterol, pre-eclampsia and ulcerative colitis. Facial birth defects, an effect observed in rat offspring, occurred with the children of two out of seven female DuPont employees from the Washington Works facility from 1979 to 1981. Bucky Bailey is one of the affected individuals; DuPont, however, does not accept any liability from the toxicity of PFOA. While 3M sent DuPont results from a study that showed birth defects to rats administered PFOA and DuPont moved the women out of the Teflon production unit, subsequent animal testing led DuPont to conclude there was no reproductive risk to women, and they were returned to the production unit. However, data released in March 2009 on the community around DuPont's Washington Works plant showed "a modest, imprecise indication of an elevation in risk ... above the 90th percentile ... based on 12 cases in the uppermost category", which was deemed "suggestive of a possible relationship" between PFOA exposure and birth defects.


Legal actions


International action: Stockholm Convention

PFOA was proposed for listing under the
Stockholm Convention on Persistent Organic Pollutants Stockholm Convention on Persistent Organic Pollutants is an international environmental treaty, signed on 22 May 2001 in Stockholm and effective from 17 May 2004, that aims to eliminate or restrict the production and use of persistent organic ...
in 2015, and on May 10, 2019, PFOA, its salts, and PFOA-related compounds were added to Annex A of the Stockholm Convention by the Conference of the Parties. Several hundred salts and precursors of PFOA fall within the scope of the restriction. A few specific exemptions remained. Among them is a time-bound exemption for PFOA in fire-fighting foam.


Industry and legal actions

DuPont has used PFOA for over 50 years at its Washington Works plant. Area residents sued DuPont in August 2001 and claimed DuPont released PFOA in excess of their community guideline of 1 part per billion resulting in lower property values and increased risk of illness. The class was certified by Wood Circuit Court Judge George W. Hill. As part of the settlement, DuPont has paid for
blood test A blood test is a laboratory analysis performed on a blood sample that is usually extracted from a vein in the arm using a hypodermic needle, or via fingerprick. Multiple tests for specific blood components, such as a glucose test or a cholester ...
s and
health surveys Health, according to the World Health Organization, is "a state of complete physical, Mental health, mental and social well-being and not merely the absence of disease and infirmity".World Health Organization. (2006)''Constitution of the World H ...
of residents believed to be affected. Participants numbered 69,030 in the study, which was reviewed by three
epidemiologists Epidemiology is the study and analysis of the distribution (who, when, and where), patterns and determinants of health and disease conditions in a defined population. It is a cornerstone of public health, and shapes policy decisions and evidenc ...
—the C8 Science Panel—to determine if any health effects are the likely result of exposure. On December 13, 2005, DuPont announced a settlement with the EPA in which DuPont would pay
US$ The United States dollar (symbol: $; code: USD; also abbreviated US$ or U.S. Dollar, to distinguish it from other dollar-denominated currencies; referred to as the dollar, U.S. dollar, American dollar, or colloquially buck) is the official ...
10.25 million in fines and an additional US$6.25 million for two supplemental environmental projects without any admission of liability. On September 30, 2008, Chief Judge Joseph R. Goodwin of the
United States District Court for the Southern District of West Virginia The United States District Court for the Southern District of West Virginia (in case citations, S.D. W. Va.) is a federal court in the Fourth Circuit (except for patent claims and claims against the U.S. government under the Tucker Act, which are ...
denied the certification of a class of Parkersburg residents exposed to PFOA from DuPont's facility because they did not "show the common individual injuries needed to certify a class action".Goodwin, C.J
"''Rhodes, et al. v. E.I. Du Pont De Nemours and Company''"
United States District Court for the Southern District of West Virginia The United States District Court for the Southern District of West Virginia (in case citations, S.D. W. Va.) is a federal court in the Fourth Circuit (except for patent claims and claims against the U.S. government under the Tucker Act, which are ...
. Case Number, 6:06-cv-530 (30 September 2008). Retrieved 12 October 2008.
On September 28, 2009, Judge Goodwin dismissed the claims of those residents except for medical monitoring. By 2015, more than three thousand plaintiffs have filed personal-injury lawsuits against DuPont. In 2017, DuPont reached a $670.7 million cash settlement related to 3,550 personal injury lawsuits tied to PFOA contamination of drinking water in the Parkersburg area. Chemours, which was spun off from DuPont in 2015, agreed to pay half the settlement. Both companies denied any wrongdoing.


U.S. federal government actions

In 2002, a panel of toxicologists, including several from EPA, proposed a level of 150 ppb for
drinking water Drinking water is water that is used in drink or food preparation; potable water is water that is safe to be used as drinking water. The amount of drinking water required to maintain good health varies, and depends on physical activity level, a ...
in the PFOA contaminated area around DuPont's Washington Works plant. This initially proposed level was much higher than any known environmental concentration and was over 2,000 times the level EPA eventually settled on for the drinking water health advisory. In July 2004, EPA filed a suit against DuPont alleging "widespread contamination" of PFOA near the Parkersburg, West Virginia plant "at levels exceeding the company's community exposure guidelines;" the suit also alleged that "DuPont had—over a 20 year period—repeatedly failed to submit information on adverse effects (in particular, information on liver enzyme alterations and birth defects in offspring of female Parkersburg workers)." In October 2005, a USFDA study was published revealing PFOA and PFOA precursor chemicals in food contact and
PTFE Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene that has numerous applications. It is one of the best-known and widely applied PFAS. The commonly known brand name of PTFE-based composition is Teflon by Chemour ...
products. On January 25, 2006, EPA announced a voluntary program with several chemical companies to reduce PFOA and PFOA precursor emissions by the year 2015. On February 15, 2005, EPA's Science Advisory Board (SAB) voted to recommended that PFOA should be considered a "likely human
carcinogen A carcinogen is any substance, radionuclide, or radiation that promotes carcinogenesis (the formation of cancer). This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes. Several radioactive substan ...
". On May 26, 2006, EPA's SAB addressed a letter to Administrator Stephen L. Johnson. Three-quarters of advisers thought the stronger "likely to be carcinogenic" descriptor was warranted, in opposition to EPA's own PFOA hazard descriptor of "suggestive evidence of carcinogenicity, but not sufficient to assess human carcinogenic potential". On November 21, 2006, EPA ordered DuPont to offer alternative drinking water or treatment for public or private water users living near DuPont's Washington Works plant in West Virginia (and in Ohio), if the level of PFOA detected in drinking water is equal to or greater than 0.5 parts per billion. This measure sharply lowered the previous action level of 150 parts per billion that was established in March 2002. According to a May 23, 2007, ''
Environmental Science & Technology ''Environmental Science & Technology'' is a biweekly peer-reviewed scientific journal published since 1967 by the American Chemical Society. It covers research in environmental science and environmental technology, including environmental policy. ...
'' Online article,
U.S. Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a federal agency of the Department of Health and Human Services. The FDA is responsible for protecting and promoting public health through the control and supervision of food ...
research regarding food contact papers as a potential source of PFOA to humans is ongoing. In November 2007, the
Centers for Disease Control and Prevention The Centers for Disease Control and Prevention (CDC) is the national public health agency of the United States. It is a United States federal agency, under the Department of Health and Human Services, and is headquartered in Atlanta, Georgi ...
(CDC) published data on PFOA concentrations comparing 1999–2000 vs. 2003–2004
NHANES The National Health and Nutrition Examination Survey (NHANES) is a survey research program conducted by the National Center for Health Statistics (NCHS) to assess the health and nutritional status of adults and children in the United States, and t ...
samples. On January 15, 2009, EPA set a provisional health advisory level of 0.4 ppb in drinking water. On May 19, 2016, EPA lowered the drinking water health advisory level to 0.07 ppb for PFOA and PFOS. In June 2022 the agency issued updated advisories, stating that "some negative health effects may occur with concentrations of PFOA or PFOS in water that are near zero and below EPA's ability to detect at this time." EPA also issued new health advisories for GenX and
PFBS Perfluorobutanesulfonic acid (PFBS) is a chemical compound having a four-carbon fluorocarbon chain and a sulfonic acid functional group. It is stable and unreactive because of the strength of carbon–fluorine bonds. It can occur in the form of ...
. In March 2021 EPA announced that it will develop drinking water standards for PFOA and PFOS in public water systems. In October 2021 the EPA proposed to designate PFOA and PFOS as hazardous substances in its PFAS Strategic Roadmap. In September 2022 the EPA proposed to designate as hazardous substances under the
Superfund Superfund is a United States federal environmental remediation program established by the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA). The program is administered by the United States Environmental Pro ...
Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA).


U.S. state government actions


New Jersey

In 2007 the
New Jersey Department of Environmental Protection The New Jersey Department of Environmental Protection (NJDEP) is a government agency in the U.S. state of New Jersey that is responsible for managing the state's natural resources and addressing issues related to pollution. NJDEP now has a staff o ...
(NJDEP) announced that it found PFOA at "elevated levels in the system's drinking water near DuPont's massive Chambers Works chemical plant". In 2018 the state published a drinking water standard for PFNA.
Public water system Public water system is a regulatory term used in the United States and Canada, referring to certain utilities and organizations providing drinking water. United States The US Safe Drinking Water Act and derivative legislation define "public water ...
s in New Jersey are required to meet a maximum contaminant level (MCL) standard of 13 ppt. In 2019 New Jersey filed lawsuits against the owners of two plants that had manufactured PFASs (the Chambers Works and the Parlin plant in
Sayreville Sayreville is a borough in Middlesex County, New Jersey, United States. Sayreville is within the heart of the Raritan Valley region, located on the south banks of the Raritan River, and also located on the Raritan Bay. As of the 2010 United Sta ...
), and two plants that were cited for water pollution from other chemicals. The companies cited are DuPont, Chemours and 3M. In 2020 the NJDEP set a PFOA standard at 14 ppt and a PFOS standard at 13 ppt.


New York

In 2018 the
New York State Department of Health The New York State Department of Health (NYSDOH) is the department of the New York state government responsible for public health. It is headed by Health Commissioner Mary T. Bassett, who was appointed by Governor Hochul and confirmed by the S ...
adopted drinking water standards of 10 ppt for PFOA and 10 ppt for PFOS, effective in 2019 after a public comment period.


Michigan

In November 2017, the Michigan PFAS Action Response Team (MPART) was created to address growing pollution concerns after multiple sites contaminated by PFAS were identified. MPART is a multi-agency team tasked with investigating PFAS contamination sites and sources in the state, protecting drinking water, enhancing interagency communication and keeping the public informed. In January 2018, Michigan established a legally enforceable groundwater cleanup level of 70 ppt for both PFOA and PFOS. Two science advisory committees were also created and joined MPART to "coordinate and review medical and environmental health, PFAS science and develop evidence-based recommendations". In August 2020, the Michigan Department Department of Environment, Great Lakes, and Energy adopted stricter drinking water standards in the form of MCLs, lowering acceptable levels from the 2018 enforceable groundwater cleanup levels of 70 ppt to 8 ppt for PFOA and 16 ppt for PFOS and adding MCLs for 5 previously unregulated PFAS compounds PFNA, PFHxA, PFHxS,
PFBS Perfluorobutanesulfonic acid (PFBS) is a chemical compound having a four-carbon fluorocarbon chain and a sulfonic acid functional group. It is stable and unreactive because of the strength of carbon–fluorine bonds. It can occur in the form of ...
, and HFPO-DA.


Minnesota

In 2007, the
Minnesota Minnesota () is a state in the upper midwestern region of the United States. It is the 12th largest U.S. state in area and the 22nd most populous, with over 5.75 million residents. Minnesota is home to western prairies, now given over to ...
Department of Health lowered its Health Based Value for PFOA in drinking water from 1.0 ppb to 0.5 ppb, where "the sources are landfilled industrial wastes from a 3M manufacturing plant".


European action

PFOA contaminated waste was incorporated into soil improver and spread on agricultural land in Germany, leading to PFOA drinking water contamination of up to 0.519
parts per billion In science and engineering, the parts-per notation is a set of pseudo-units to describe small values of miscellaneous dimensionless quantities, e.g. mole fraction or mass fraction. Since these fractions are quantity-per-quantity measures, they ...
. The German Federal Environmental Agency issued guidelines for the sum of PFOA and
PFOS Perfluorooctanesulfonic acid (PFOS) (conjugate base perfluorooctanesulfonate) is a chemical compound having an eight-carbon fluorocarbon chain and a sulfonic acid functional group and thus a perfluorosulfonic acid. It is an anthropogenic (man ...
concentrations in drinking water: 0.1 parts per billion for precaution and 0.3 parts per billion for a threshold. Residents were found to have a 6–8 factor increase of PFOA serum levels over unexposed Germans, with average PFOA concentrations in the 22–27 parts per billion range. An expert panel concluded that "concentrations were considered too low to cause overt adverse health effects in the exposed population". In the Netherlands, after questions by members of Parliament, the minister of Environment ordered a study into the potential exposure to PFOA of people living in the vicinity of the DuPont factory in
Dordrecht Dordrecht (), historically known in English as Dordt (still colloquially used in Dutch, ) or Dort, is a city and municipality in the Western Netherlands, located in the province of South Holland. It is the province's fifth-largest city after R ...
. The report was published in March 2016 and concluded that "prior to 2002 residents were exposed to levels of PFOA at which health effects could not be ruled out". As a result of this, the government commissioned several further studies, including blood tests and measurements in drinking water. PFOA was identified as a PBT substance in the EU in 2013. It was then included in the candidate list of substances of very high concern. In 2017, PFOA, its salts and PFOA-related substances were added to annex XVII (restriction) of the
REACH Regulation Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) is a European Union regulation dating from 18 December 2006. REACH addresses the production and use of chemical substances, and their potential impacts on both human he ...
. The EU adopted the listing of PFOA in Annex A of the Stockholm Convention with Commission Delegated Regulation (EU) 2020/784 of 8 April 2020 and introduced a limit value of 0,025 mg/kg for PFOA including its salts, and at 1 mg/kg for the individual PFOA-related compounds or a combination of those compounds. They also included some specific exemptions. Among them is a time-bound exemption for PFOA in fire-fighting foam.


Australian action

On August 10, 2016, Australian litigation funder IMF Bentham announced an agreement to fund a class action led by the law firm Gadens against the Australian Department of Defence for economic losses to homeowners, fishers, and farmers resulting from the use of
aqueous film forming foam Firefighting foam is a foam used for fire suppression. Its role is to cool the fire and to coat the fuel, preventing its contact with oxygen, thus achieving suppression of the combustion. Firefighting foam was invented by the Russian engineer a ...
(containing PFOA) at
RAAF Base Williamtown RAAF Base Williamtown is a Royal Australian Air Force (RAAF) military air base located north of the coastal city of Newcastle ( by road) in the local government area of Port Stephens, in New South Wales, Australia. The base serves as the h ...
.


See also

*
Timeline of events related to per- and polyfluoroalkyl substances (PFAS) A timeline is a display of a list of events in chronological order. It is typically a graphic design showing a long bar labelled with dates paralleling it, and usually contemporaneous events. Timelines can use any suitable scale representi ...


References


External links


US EPA: Per- and Polyfluoroalkyl Substances (PFAS)
– Overview, regulatory actions, tools & resources
Sustained Outrage Blog – C8 (PFOA) Category
published by the ''
Charleston Gazette The ''Charleston Gazette-Mail'' is the only daily morning newspaper in Charleston, West Virginia. It is the product of a July 2015 merger between ''The Charleston Gazette'' and the ''Charleston Daily Mail''. The paper is one of nine owned by HD ...
''
Internet Movie Database (IMDB) listing ''The Devil We Know''

Callie Lyons blog on C8
author of ''Stain-Resistant, Nonstick, Waterproof, and Lethal: The Hidden Dangers of C8''
Perfluorooctanoic Acid (PFOA); Fluorinated Telomers enforceable consent agreement development

Perfluorinated substances and their uses in Sweden

Chain of Contamination: The Food Link, Perfluorinated Chemicals (PFCs) Incl. PFOS & PFOA
{{PPAR modulators Anionic surfactants Perfluorocarboxylic acids IARC Group 2B carcinogens PBT substances Persistent organic pollutants under the Stockholm Convention