Perfluorooctanoic acid
Encyclopedia
Perfluorooctanoic acid also known as C8 and perfluorooctanoate, is a synthetic, stable perfluorinated carboxylic acid
and fluorosurfactant
. One industrial application is as a surfactant
in the emulsion polymerization
of fluoropolymers. It has been used in the manufacture of such prominent consumer goods as Teflon and Gore-Tex
. PFOA has been manufactured since the 1940s in industrial quantities. It is also formed by the degradation
of precursors
such as some fluorotelomer
s.
PFOA persists indefinitely in the environment. It is a toxicant
and carcinogen
in animals. PFOA has been detected in the blood of more than 98% of the general US population in the low and sub-parts per billion range, and levels are higher in chemical plant employees and surrounding subpopulations. Exposure has been associated with increased cholesterol
and uric acid
levels, and recently higher serum levels of PFOA were found to be associated with increased risk of chronic kidney disease in the general United States population, consistent with earlier animal studies. "This association was independent of confounders such as age, sex, race/ethnicity, body mass index, diabetes, hypertension, and serum cholesterol level."
As a result of a class-action lawsuit and community settlement with DuPont
, three epidemiologists
are conducting studies on the population surrounding a chemical plant that was exposed to PFOA at levels greater than in the general population. If PFOA exposure is found to be likely to lead to an increased risk of disease, future liabilities for DuPont will be triggered. Full results from the studies are expected in 2012.
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, microwave popcorn bags
, water, food, and PTFE. Although some cookware is marketed
as PFOA-free, PTFE non-stick cookware
is considered an insignificant exposure pathway.
began producing PFOA by electrochemical fluorination
. In 1951, DuPont
started using PFOA in the manufacturing of fluoropolymers in Washington, WV. In 1961, DuPont was aware of hepatomegaly
in mice fed with PFOA. In 1968, organofluorine
content was detected in the blood serum
of consumers, and in 1976 it was suggested to be PFOA or a related compound such as PFOS. In the 1980s and 1990s researchers investigated the toxicity
of PFOA.
In 1999, the United States Environmental Protection Agency
(USEPA) began investigating perfluorinated chemicals after receiving data on the global distribution and toxicity of PFOS. For these reasons, and USEPA pressure, in May 2000, 3M announced the phaseout of the production of PFOA, PFOS, and PFOS-related products. 3M stated that they would have made the same decision regardless of USEPA pressure.
Because of the 3M phaseout, in 2002 DuPont built its own plant in Fayetteville, NC to manufacture the chemical. The chemical has received attention due to litigation from the PFOA-contaminated community around DuPont's Washington Works Washington, WV facility, along with USEPA focus. 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
in recent years have allowed the routine detection of low- and sub-parts per billion levels of PFOA in a variety of substances.
(ECF) and telomerization
. The equation below represents the ECF route with hydrofluoric acid
reacting with octanoic acid chloride.
The equation above shows the multiple products of ECF. The target product, F(CF2)7COF
(not represented) is produced as only 10–15% of the total product, while the main products are perfluorinated
cyclic ether
isomer
s, including FC-75
. To yield PFOA, the perfluorinated acid fluoride is hydrolyzed. The PFOA formed by this method is a mixture of straight chain (78%), terminally branched (13%), and internally branched (9%) molecules, as ECF rearranges the carbon "tail" of the acid chloride. ECF also results in production wastes. 3M
synthesized ECF PFOA at their Cottage Grove, MN 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
represented below, where the telogen is the organoiodine compound
and the taxogen is the unsaturated
tetrafluoroethylene
.
The product is oxidized by SO3
to form PFOA. Under reaction conditions, telomers form with varying length chains containing an even number of carbon atoms, as products mostly contain two to six tetrafluoroethylene taxogens. After oxidation, distillation
is used to separate PFOA from the other perfluorinated carboxylic acids. The telomerization synthesis of PFOA was pioneered by DuPont
, and it is not well suited to the laboratory. PFOA formed by telomerization is completely linear, in contrast to the mixture of structures formed by ECF.
, but with fluorotelomer
s with less than 0.1% PFOA. The compound is also used in "insulators for electric wires
, planar etching of fused silica", fire fighting foam, 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, the dominant use is as an emulsifier
for the emulsion polymerization
of fluoropolymers such as polytetrafluoroethylene
(PTFE, or Teflon), polyvinylidene fluoride
, and fluoroelastomer
s. For this use, 3M subsidiary Dyneon has a replacement emulsifer despite DuPont stating PFOA is an "essential processing aid". PFOA is used in the production of Gore-Tex
as it is PTFE-based. In PTFE processing, PFOA is in aqueous solution
and forms micelle
s that contain tetrafluoroethylene
and the growing polymer
. PFOA can be used to stabilize fluoropolymer and fluoroelastomer suspensions prior to further industrial processing and in ion-pair reversed-phase liquid chromatography it can act as an extraction agent. PFOA also finds uses in electronic products and as an industrial fluorosurfactant
.
In a 2009 USEPA 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
in parenthesis) to 6750 with concentrations in nanograms of PFOA per gram
of sample—or parts per billion—unless stated otherwise.
The carboxylate "head" of PFOA is hydrophilic while the fluorocarbon
tail is hydrophobic and lipophobic. The "tail" is hydrophobic due to being non-polar and lipophobic because fluorocarbons are less susceptible to the London dispersion force
than hydrocarbons. PFOA is an ideal surfactant because it can lower the surface tension
of water more than hydrocarbon
surfactants while possessing exceptional stability due to the presence of multiple carbon–fluorine bond
s. The stability of PFOA is desired industrially, but a cause of concern environmentally. PFOA is resistant to degradation by natural processes such as metabolism
, hydrolysis
, photolysis, or biodegradation
making it persist indefinitely in the environment.
PFOA is found in environmental and biological fluids as the anion perfluorooctanoate. PFOA is absorbed from ingestion and can penetrate skin
. The oxygens on PFOA are how it binds proteins with fatty acid
or hormone
substrates such as serum albumin
, liver
fatty acid
-binding protein, and the nuclear receptor
s PPARα
and possibly CAR
. In animals, PFOA is mainly present in the liver
, blood
, and kidneys. PFOA does not accumulate in fat tissue, unlike traditional organohalogen persistent organic pollutants. In humans, PFOA has an average elimination half-life
of about 3 years. Because of this long half-life, PFOA has the potential to bioaccumulate.
. PFOA has been detected in the central Pacific Ocean at low parts per quadrillion ranges, and at low parts per trillion levels in coastal waters. 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
s, and is present in numerous mammals, fish, and bird species. However, wildlife has much less PFOA than humans, unlike PFOS and other longer perfluorinated carboxylic acid
s; in wildlife, PFOA is not as bioaccumulative as longer perfluorinated carboxylic acids.
Most industrialized nations have average PFOA blood serum
levels ranging from 2 to 8 parts per billion; the highest consumer sub-population identified was in Korea—with about 60 parts per billion. In Peru
, Vietnam
, and Afghanistan
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 is increasing in the blood of US consumers.
) in 2000 and 1,700 pounds in 2004. A 2006 study, with two of four authors DuPont employees, estimated about 80% of historical perfluorocarboxylate emissions were released to the environment from fluoropolymer
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, paper and electronics industries.
The most important emission sources are carpet and textile protection as well as fire-fighting foams.
PFOA can form as a breakdown product from a variety of precursor molecules. PFOA precursors can be transformed to PFOA by metabolism, biodegradation, or atmospheric processes. Examples include 8:2 fluorotelomer alcohol
(F(CF2)8CH2CH2OH), polyfluoroalkyl phosphate surfactants (PAPS), and possibly N-EtFOSE alcohol (F(CF2)8SO2N(Et)CH2CH2OH). When PTFE is degraded by heat (pyrolysis
) it can form PFOA as a minor product. The Organisation for Economic Co-operation and Development
(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 (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
-based polymers; fluorotelomer alcohols attached to hydrocarbon backbones via ester
linkages may detach and be free to biodegrade to PFOA.
, drinking water
, outdoor air, indoor air, dust
, and food packaging
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.
Citizens that lived in the PFOA contaminated area around DuPont's Washington Works Washington, WV 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
systems had lower PFOA levels.
PFOA is also formed as an unintended byproduct in the production of fluorotelomer
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
: they prevent oil from soaking into the paper from fatty foods. Also, fluorotelomers can be metabolized into PFOA. In an U.S. Food and Drug Administration (USFDA) study, lipophobic 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, while microwave popcorn bags
contained 6–290 parts per billion PFOA. 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. 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 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.
s of land were fertilized with "treated municipal sewage sludge
, or biosolids." PFOA was also detected in the blood of the cattle. The water treatment plant received process wastewater from a nearby perfluorochemical
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
reported—with a detection limits of 20 parts per billion—non-detectable levels for both PFOA and PFOS in cattle muscle tissue.
in the US, on January 15, 2009, the Bush administration U.S. Environmental Protection Agency
(USEPA) set a "provisional health advisory" of 0.4 parts per billion in response to the detection of PFOA in agricultural soil. However, the advisory is not meant to protect the public from long term exposure but might protect individuals for "a couple of years." While water companies are not required to test for PFOA, it is a potential candidate for regulation under the Safe Drinking Water Act
. As for consumer products, there is no federal safety standard for PFOA in the US.
and the Environmental Working Group
, was approved that would have banned PFOA, PFOS, and related seven or more 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, and Schwarzenegger was lobbied by the chemical industry to veto. Schwarzenegger said the compound should be reviewed by the newly established, and more comprehensive, state program.
, liver toxicant, a developmental toxicant, an immune system toxicant, and also exerts hormonal effects including alteration of thyroid hormone
levels. Animal studies show developmental toxicity from reduced birth size, physical developmental delays, endocrine disruption, and neonatal mortality
. PFOA causes liver cancer
in rodents and also induces testicular
and pancreatic cancer
through induction of Leydig cell
tumors and pancreatic acinar cell
tumors. PFOA alters lipid metabolism
. It is an agonist
of PPARα
and is a peroxisome
proliferator in rodents contributing to a well understood form of oxidative stress
. Humans are considered less susceptible to peroxisome proliferation than rodents. However, PFOA has been found to be a liver carcinogen in rainbow trout
via a potential estrogenic mechanism, which may be more relevant to humans. A study found PFOA to be an obesogen
in female mice at mid-age—with altered levels of insulin
and leptin
—at the lowest dose of 0.01 milligrams per kilogram of body weight during development.
While a USEPA review notes PFOA has not "been shown to be mutagenic in a variety of assays" in 1991 researchers from Japan demonstrated oxidative
liver DNA
damage in an experiment with rats. 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
via a peroxisome proliferation pathway that produced oxygen radicals
in HepG2 cells, and a 2006 study demonstrated the induction and suppression of a broad range of genes; therefore, it states that the indirect genotoxic (and thus carcinogenic) potential of PFOA cannot be dismissed. Criteria have been proposed that would allow PFOA, and other perfluorinated compounds, to be classified as "weakly non-specific genotoxic
."
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.
on consumers have been published noting multiple associations. Blood serum levels of PFOA were associated with an increased time to pregnancy—or "infertility
"—in a 2009 study. PFOA exposure was associated with decreased semen quality
, increased serum alanine aminotransferase levels, and increased occurrence of thyroid disease
. In a study of 2003–2004 US samples, a higher (9.8 milligram per deciliter) total cholesterol level was observed when the highest quartile
was compared to the lowest. Along with other related compounds, PFOA exposure was associated with an increased risk of attention deficit hyperactivity disorder (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
by a potential mechanism on breast
maturation in young girls. A C8 Science Panel status report noted an association between exposure in girls and a later onset of puberty
.
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. PFOA exposure in the Danish general population was not associated with an increased risk of prostate
, bladder
, pancreatic
, or liver cancer
. 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.
of the epidemiological
evidence on PFOA exposure in Environmental Health Perspectives
. 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
is unknown. Further data on the 69,030 member cohort that is being studied by the panel is scheduled for release through 2012.
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, however, DuPont 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.
s and health surveys
of residents believed to be affected. Participants number 69,030 in the study, which will be reviewed by three epidemiologists
—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 will pay US$
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
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." On September 28, 2009, Judge Goodwin dismissed the claims of those residents except for medical monitoring.
in the PFOA contaminated area around DuPont's Washington Works WV plant; this level was much higher than any known environmental concentration.
In July 2004, the USEPA filed a suit against DuPont alleging "widespread contamination" of PFOA near the Parkersburg, WV, 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 products.
On January 25, 2006, the USEPA announced a voluntary program with several chemical companies to reduce PFOA and PFOA precursor emissions by the year 2015.
On February 15, 2005, the USEPA's Science Advisory Board (SAB) voted to recommended that PFOA should be considered a "likely human carcinogen
."
On May 26, 2006, the USEPA's SAB addressed a letter to Stephen L. Johnson
. Three-quarters of advisers thought the stronger "likely to be carcinogenic" descriptor was warranted, in opposition to the USEPA's own PFOA hazard descriptor of "suggestive evidence of carcinogenicity, but not sufficient to assess human carcinogenic potential."
On November 21, 2006, the USEPA ordered DuPont company 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
Online article, U.S. Food and Drug Administration 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
(CDC) published data on PFOA concentrations comparing 1999–2000 vs. 2003–2004 NHANES
samples.
On January 15, 2009, the USEPA set a provisional health advisory level of 0.4 parts per billion in drinking water.
On March 1, 2007, the Minnesota Department of Health lowered its Health Based Value for PFOA in drinking water from 1.0 parts per billion to 0.5 parts per billion, where "the sources are landfilled industrial wastes from a 3M manufacturing plant."
Perfluorinated carboxylic acid
Perfluorinated carboxylic acids , or perfluorocarboxylates are fully fluorinated organofluorine compounds—or perfluorinated compounds—with carboxylic acid or carboxylate functional groups. PFCAs are fluorocarbon derivatives...
and fluorosurfactant
Fluorosurfactant
Fluorosurfactants, or fluorinated surfactants, are synthetic organofluorine chemical compounds that have multiple fluorine atoms. They can be polyfluorinated or fluorocarbon-based . As surfactants, they are more effective at lowering the surface tension of water than comparable hydrocarbon...
. One industrial application is as a surfactant
Surfactant
Surfactants are compounds that lower the surface tension of a liquid, the interfacial tension between two liquids, or that between a liquid and a solid...
in the emulsion polymerization
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 are emulsified in a continuous phase of water...
of fluoropolymers. It has been used in the manufacture of such prominent consumer goods as Teflon and Gore-Tex
Gore-Tex
Gore-Tex is a waterproof/breathable fabric, and a registered trademark of W. L. Gore and Associates. It was co-invented by Wilbert L. Gore, Rowena Taylor, and Gore's son, Robert W. Gore. Robert Gore was granted on April 27, 1976, for a porous form of polytetrafluoroethylene with a...
. PFOA has been manufactured since the 1940s in industrial quantities. It is also formed by the degradation
Chemical decomposition
Chemical decomposition, analysis or breakdown is the separation of a chemical compound into elements or simpler compounds. It is sometimes defined as the exact opposite of a chemical synthesis. Chemical decomposition is often an undesired chemical reaction...
of precursors
Precursor (chemistry)
In chemistry, a precursor is a compound that participates in the chemical reaction that produces another compound. In biochemistry, the term "precursor" is used more specifically to refer to a chemical compound preceding another in a metabolic pathway....
such as some fluorotelomer
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, while others are under extended...
s.
PFOA persists indefinitely in the environment. It is a toxicant
Toxicant
A toxicant is a chemical compound that has an effect on organisms.A distinction can be drawn between "toxic" and toxin, with the latter being a subcategory of the former....
and carcinogen
Carcinogen
A carcinogen is any substance, radionuclide, or radiation that is an agent directly involved in causing cancer. This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes...
in animals. PFOA has been detected in the blood of more than 98% of the general US population in the low and sub-parts per billion range, and levels are higher in chemical plant employees and surrounding subpopulations. Exposure has been associated with increased cholesterol
Cholesterol
Cholesterol is a complex isoprenoid. Specifically, it is a waxy steroid of fat that is produced in the liver or intestines. It is used to produce hormones and cell membranes and is transported in the blood plasma of all mammals. It is an essential structural component of mammalian cell membranes...
and uric acid
Uric acid
Uric acid is a heterocyclic compound of carbon, nitrogen, oxygen, and hydrogen with the formula C5H4N4O3. It forms ions and salts known as urates and acid urates such as ammonium acid urate. Uric acid is created when the body breaks down purine nucleotides. High blood concentrations of uric acid...
levels, and recently higher serum levels of PFOA were found to be associated with increased risk of chronic kidney disease in the general United States population, consistent with earlier animal studies. "This association was independent of confounders such as age, sex, race/ethnicity, body mass index, diabetes, hypertension, and serum cholesterol level."
As a result of a class-action lawsuit and community settlement with DuPont
DuPont
E. I. du Pont de Nemours and Company , commonly referred to as DuPont, is an American chemical company that was founded in July 1802 as a gunpowder mill by Eleuthère Irénée du Pont. DuPont was the world's third largest chemical company based on market capitalization and ninth based on revenue in 2009...
, three epidemiologists
Epidemiology
Epidemiology is the study of health-event, health-characteristic, or health-determinant patterns in a population. It is the cornerstone method of public health research, and helps inform policy decisions and evidence-based medicine by identifying risk factors for disease and targets for preventive...
are conducting studies on the population surrounding a chemical plant that was exposed to PFOA at levels greater than in the general population. If PFOA exposure is found to be likely to lead to an increased risk of disease, future liabilities for DuPont will be triggered. Full results from the studies are expected in 2012.
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, microwave popcorn bags
Popcorn bag
A microwave popcorn bag is an engineered, enhanced, sealed paper bag in which un-popped popcorn is sold for the purpose of cooking popcorn in a microwave oven. These bags and their contents are sometimes referred to as microwave popcorn...
, water, food, and PTFE. Although some cookware is marketed
Marketing
Marketing is the process used to determine what products or services may be of interest to customers, and the strategy to use in sales, communications and business development. It generates the strategy that underlies sales techniques, business communication, and business developments...
as PFOA-free, PTFE non-stick cookware
Non-stick pan
Non-stick pans are cooking pans made from or coated with materials designed to prevent food from sticking to their surface during the cooking process. Most non-stick pans are made using Teflon coating although newer materials are also used...
is considered an insignificant exposure pathway.
History
In 1947, 3M3M
3M Company , formerly known as the Minnesota Mining and Manufacturing Company, is an American multinational conglomerate corporation based in Maplewood, Minnesota, United States....
began producing PFOA by electrochemical fluorination
Electrochemical fluorination
Electrochemical fluorination , or electrofluorination, is a foundational organofluorine chemistry method for the preparation of fluorocarbon-based organofluorine compounds. The general approach represents an application of electrosynthesis...
. In 1951, DuPont
DuPont
E. I. du Pont de Nemours and Company , commonly referred to as DuPont, is an American chemical company that was founded in July 1802 as a gunpowder mill by Eleuthère Irénée du Pont. DuPont was the world's third largest chemical company based on market capitalization and ninth based on revenue in 2009...
started using PFOA in the manufacturing of fluoropolymers in Washington, WV. In 1961, DuPont was aware of hepatomegaly
Hepatomegaly
Hepatomegaly is the condition of having an enlarged liver. It is a nonspecific medical sign having many causes, which can broadly be broken down into infection, direct toxicity, hepatic tumours, or metabolic disorder. Often, hepatomegaly will present as an abdominal mass...
in mice fed with PFOA. In 1968, organofluorine
Organofluorine
Organofluorine compounds are organic chemical compounds that contain carbon and fluorine bonded in the polarized and remarkably strong carbon–fluorine bond. Organofluorine compounds are diverse, they can be fluorocarbons, perfluorinated, or biologically synthesized mono-fluorinated compounds, among...
content was detected in the blood serum
Blood serum
In blood, the serum is the component that is neither a blood cell nor a clotting factor; it is the blood plasma with the fibrinogens removed...
of consumers, and in 1976 it was suggested to be PFOA or a related compound such as PFOS. In the 1980s and 1990s researchers investigated the toxicity
Toxicity
Toxicity is the degree to which a substance can damage a living or non-living organisms. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a substructure of the organism, such as a cell or an organ , such as the liver...
of PFOA.
In 1999, the United States Environmental Protection Agency
United States Environmental Protection Agency
The U.S. Environmental Protection Agency is an agency of the federal government of the United States charged with protecting human health and the environment, by writing and enforcing regulations based on laws passed by Congress...
(USEPA) began investigating perfluorinated chemicals after receiving data on the global distribution and toxicity of PFOS. For these reasons, and USEPA pressure, in May 2000, 3M announced the phaseout of the production of PFOA, PFOS, and PFOS-related products. 3M stated that they would have made the same decision regardless of USEPA pressure.
Because of the 3M phaseout, in 2002 DuPont built its own plant in Fayetteville, NC to manufacture the chemical. The chemical has received attention due to litigation from the PFOA-contaminated community around DuPont's Washington Works Washington, WV facility, along with USEPA focus. 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
Analytical chemistry is the study of the separation, identification, and quantification of the chemical components of natural and artificial materials. Qualitative analysis gives an indication of the identity of the chemical species in the sample and quantitative analysis determines the amount of...
in recent years have allowed the routine detection of low- and sub-parts per billion levels of PFOA in a variety of substances.
Synthesis
PFOA has two main synthesis routes, electrochemical fluorinationElectrochemical fluorination
Electrochemical fluorination , or electrofluorination, is a foundational organofluorine chemistry method for the preparation of fluorocarbon-based organofluorine compounds. The general approach represents an application of electrosynthesis...
(ECF) and telomerization
Telomerization
Telomerization is a radical polymerization reaction where a chain transfer limits the size of the oligomer molecule product—the telomer. Telomerization requires a telogen to react with at least one unsaturated taxogen molecule. Fluorotelomers are an example.-See also:*Perfluorooctanoic acid...
. The equation below represents the ECF route with hydrofluoric acid
Hydrofluoric acid
Hydrofluoric acid is a solution of hydrogen fluoride in water. It is a valued source of fluorine and is the precursor to numerous pharmaceuticals such as fluoxetine and diverse materials such as PTFE ....
reacting with octanoic acid chloride.
- H(CH2)7COCl + 17 HF → H(CH2)7COF + C7H16 + 2 C8F16O + HCl + H2
The equation above shows the multiple products of ECF. The target product, F(CF2)7COF
Acyl halide
An acyl halide is a chemical compound derived from an oxoacid by replacing a hydroxyl group with a halide group....
(not represented) is produced as only 10–15% of the total product, while the main products are perfluorinated
Fluorocarbon
Fluorocarbons, sometimes referred to as perfluorocarbons or PFCs, are organofluorine compounds that contain only carbon and fluorine bonded together in strong carbon–fluorine bonds. Fluoroalkanes that contain only single bonds are more chemically and thermally stable than alkanes...
cyclic ether
Ether
Ethers are a class of organic compounds that contain an ether group — an oxygen atom connected to two alkyl or aryl groups — of general formula R–O–R'. A typical example is the solvent and anesthetic diethyl ether, commonly referred to simply as "ether"...
isomer
Isomer
In chemistry, isomers are compounds with the same molecular formula but different structural formulas. Isomers do not necessarily share similar properties, unless they also have the same functional groups. There are many different classes of isomers, like stereoisomers, enantiomers, geometrical...
s, including FC-75
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 as a solvent. FC-75 can be synthesized by the same...
. To yield PFOA, the perfluorinated acid fluoride is hydrolyzed. The PFOA formed by this method is a mixture of straight chain (78%), terminally branched (13%), and internally branched (9%) molecules, as ECF rearranges the carbon "tail" of the acid chloride. ECF also results in production wastes. 3M
3M
3M Company , formerly known as the Minnesota Mining and Manufacturing Company, is an American multinational conglomerate corporation based in Maplewood, Minnesota, United States....
synthesized ECF PFOA at their Cottage Grove, MN 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
Telomerization is a radical polymerization reaction where a chain transfer limits the size of the oligomer molecule product—the telomer. Telomerization requires a telogen to react with at least one unsaturated taxogen molecule. Fluorotelomers are an example.-See also:*Perfluorooctanoic acid...
represented below, where the telogen is the organoiodine compound
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...
and the taxogen is the unsaturated
Unsaturated compound
In organic chemistry, a saturated compound is a chemical compound that has of a chain of carbon atoms linked together by single bonds and has hydrogen atoms filling all of the other bonding orbitals of the carbon atoms. Alkanes are an example of saturated compounds...
tetrafluoroethylene
Tetrafluoroethylene
Tetrafluoroethylene is a chemical compound with the formula C2F4. It is the simplest alkene fluorocarbon. This gaseous species is used primarily in the industrial preparation of polymers.-Properties:...
.
- C2F5I + 3 C2F4 → C2F5(C2F4)3I
The product is oxidized by SO3
Sulfur trioxide
Sulfur trioxide is the chemical compound with the formula SO3. In the gaseous form, this species is a significant pollutant, being the primary agent in acid rain. It is prepared on massive scales as a precursor to sulfuric acid.-Structure and bonding:Gaseous SO3 is a trigonal planar molecule of...
to form PFOA. Under reaction conditions, telomers form with varying length chains containing an even number of carbon atoms, as products mostly contain two to six tetrafluoroethylene taxogens. After oxidation, distillation
Distillation
Distillation is a method of separating mixtures based on differences in volatilities of components in a boiling liquid mixture. Distillation is a unit operation, or a physical separation process, and not a chemical reaction....
is used to separate PFOA from the other perfluorinated carboxylic acids. The telomerization synthesis of PFOA was pioneered by DuPont
DuPont
E. I. du Pont de Nemours and Company , commonly referred to as DuPont, is an American chemical company that was founded in July 1802 as a gunpowder mill by Eleuthère Irénée du Pont. DuPont was the world's third largest chemical company based on market capitalization and ninth based on revenue in 2009...
, and it 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 papers"; however, it is believed that paper is no longer treated with perfluorinated compoundsPerfluorinated compounds
A perfluorinated compound is an organofluorine compound with all hydrogens replaced by fluorine on a carbon chain—but the molecule also contains at least one different atom or functional group. Thus, PFCs have properties similar to fluorocarbons as they are fluorocarbon derivatives...
, but with fluorotelomer
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, while others are under extended...
s with less than 0.1% PFOA. The compound is also used in "insulators for electric wires
Electrical wiring
Electrical wiring in general refers to insulated conductors used to carry electricity, and associated devices. This article describes general aspects of electrical wiring as used to provide power in buildings and structures, commonly referred to as building wiring. This article is intended to...
, planar etching of fused silica", fire fighting foam, 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, the dominant use is as an emulsifier
Emulsion
An emulsion is a mixture of two or more liquids that are normally immiscible . Emulsions are part of a more general class of two-phase systems of matter called colloids. Although the terms colloid and emulsion are sometimes used interchangeably, emulsion is used when both the dispersed and the...
for the emulsion polymerization
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 are emulsified in a continuous phase of water...
of fluoropolymers such as polytetrafluoroethylene
Polytetrafluoroethylene
Polytetrafluoroethylene is a synthetic fluoropolymer of tetrafluoroethylene that finds numerous applications. PTFE is most well known by the DuPont brand name Teflon....
(PTFE, or Teflon), polyvinylidene fluoride
Polyvinylidene fluoride
Polyvinylidene fluoride, or PVDF is a highly non-reactive and pure thermoplastic fluoropolymer.PVDF is a specialty plastic material in the fluoropolymer family; it is used generally in applications requiring the highest purity, strength, and resistance to solvents, acids, bases and heat and low...
, and fluoroelastomer
Fluoroelastomer
A fluoroelastomer is a special purpose fluorocarbon-based synthetic rubber. It has wide chemical resistance and superior performance, especially in high temperature application in different media....
s. For this use, 3M subsidiary Dyneon has a replacement emulsifer despite DuPont stating PFOA is an "essential processing aid". PFOA is used in the production of Gore-Tex
Gore-Tex
Gore-Tex is a waterproof/breathable fabric, and a registered trademark of W. L. Gore and Associates. It was co-invented by Wilbert L. Gore, Rowena Taylor, and Gore's son, Robert W. Gore. Robert Gore was granted on April 27, 1976, for a porous form of polytetrafluoroethylene with a...
as it is PTFE-based. In PTFE processing, PFOA is in aqueous solution
Aqueous solution
An aqueous solution is a solution in which the solvent is water. It is usually shown in chemical equations by appending aq to the relevant formula, such as NaCl. The word aqueous means pertaining to, related to, similar to, or dissolved in water...
and forms micelle
Micelle
A micelle is an aggregate of surfactant molecules dispersed in a liquid colloid. A typical micelle in aqueous solution forms an aggregate with the hydrophilic "head" regions in contact with surrounding solvent, sequestering the hydrophobic single tail regions in the micelle centre. This phase is...
s that contain tetrafluoroethylene
Tetrafluoroethylene
Tetrafluoroethylene is a chemical compound with the formula C2F4. It is the simplest alkene fluorocarbon. This gaseous species is used primarily in the industrial preparation of polymers.-Properties:...
and the growing polymer
Polymer
A polymer is a large molecule composed of repeating structural units. These subunits are typically connected by covalent chemical bonds...
. PFOA can be used to stabilize fluoropolymer and fluoroelastomer suspensions prior to further industrial processing and in ion-pair reversed-phase liquid chromatography it can act as an extraction agent. PFOA also finds uses in electronic products and as an industrial fluorosurfactant
Fluorosurfactant
Fluorosurfactants, or fluorinated surfactants, are synthetic organofluorine chemical compounds that have multiple fluorine atoms. They can be polyfluorinated or fluorocarbon-based . As surfactants, they are more effective at lowering the surface tension of water than comparable hydrocarbon...
.
In a 2009 USEPA 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
Detection limit
In analytical chemistry, the detection limit, lower limit of detection, or LOD , is the lowest quantity of a substance that can be distinguished from the absence of that substance within a stated confidence limit...
in parenthesis) to 6750 with concentrations in nanograms of PFOA per gram
Gram
The gram is a metric system unit of mass....
of sample—or parts per billion—unless stated otherwise.
| Product | Range |
|---|---|
| Pre-treated carpet Carpet A carpet is a textile floor covering consisting of an upper layer of "pile" attached to a backing. The pile is generally either made from wool or a manmade fibre such as polypropylene,nylon or polyester and usually consists of twisted tufts which are often heat-treated to maintain their... ing |
ND (<1.5) to 462 |
| Carpet-care liquids Carpet cleaning Carpet cleaning, for beautification, and the removal of stains, dirt, grit, sand, and allergens can be achieved by several methods, both traditional and modern... |
19 to 6750 |
| Treated apparel | 5.4 to 161 |
| Treated upholstery Upholstery Upholstery is the work of providing furniture, especially seats, with padding, springs, webbing, and fabric or leather covers. The word upholstery comes from the Middle English word upholder, which referred to a tradesman who held up his goods. The term is equally applicable to domestic,... |
0.6 to 293 |
| Treated home textile Textile A textile or cloth is a flexible woven material consisting of a network of natural or artificial fibres often referred to as thread or yarn. Yarn is produced by spinning raw fibres of wool, flax, cotton, or other material to produce long strands... s |
3.8 to 438 |
| Treated non-woven medical garments | 46 to 369 |
| Industrial floor wax Wax thumb|right|[[Cetyl palmitate]], a typical wax ester.Wax refers to a class of chemical compounds that are plastic near ambient temperatures. Characteristically, they melt above 45 °C to give a low viscosity liquid. Waxes are insoluble in water but soluble in organic, nonpolar solvents... and wax removers |
7.5 to 44.8 |
| Stone, tile, and wood sealant Sealant A sealant may be viscous material that has little or no flow characteristics and stay where they are applied or thin and runny so as to allow it to penetrate the substrate by means of capillary reaction... s |
477 to 3720 |
| Membrane Artificial membrane An artificial membrane, or synthetic membrane, is a synthetically created membrane which is usually intended for separation purposes in laboratory or in industry. Synthetic membranes have been successfully used for small and large-scale industrial processes since the middle of twentieth century. A... s for apparel |
0.1 to 2.5 ng/cm2 |
| Food contact paper Food contact materials Food contact materials are materials that are intended to be in contact with food. These can be things that are quite obvious like a glass, a can for soft drinks, but also machinery in a food factory or a coffee machine.... |
ND (<1.5) to 4640 |
| Dental floss Dental floss Dental floss is made of either a bundle of thin nylon filaments or a plastic ribbon used to remove food and dental plaque from teeth. The floss is gently inserted between the teeth and scraped along the teeth sides, especially close to the gums. Dental floss may be flavored or unflavored, and... /tape |
ND (<1.5) to 96.7 |
| Thread sealant tape Thread seal tape Thread seal tape, or teflon tape can be used in many ways, the most common use in America is to seal things. Thread seal tape — commonly known as "Teflon tape", "PTFE tape", "tape dope", or "plumber's tape"–is a polytetrafluoroethylene film cut to specified widths for use in sealing pipe... |
ND (<1.5) to 3490 |
| PTFE cookware Non-stick pan Non-stick pans are cooking pans made from or coated with materials designed to prevent food from sticking to their surface during the cooking process. Most non-stick pans are made using Teflon coating although newer materials are also used... |
ND (<1.5) to 4.3 |
Properties
Fluorocarbon
Fluorocarbons, sometimes referred to as perfluorocarbons or PFCs, are organofluorine compounds that contain only carbon and fluorine bonded together in strong carbon–fluorine bonds. Fluoroalkanes that contain only single bonds are more chemically and thermally stable than alkanes...
tail is hydrophobic and lipophobic. The "tail" is hydrophobic due to being non-polar and lipophobic because fluorocarbons are less susceptible to the London dispersion force
London dispersion force
London dispersion forces is a type of force acting between atoms and molecules. They are part of the van der Waals forces...
than hydrocarbons. PFOA is an ideal surfactant because it can lower the surface tension
Surface tension
Surface tension is a property of the surface of a liquid that allows it to resist an external force. It is revealed, for example, in floating of some objects on the surface of water, even though they are denser than water, and in the ability of some insects to run on the water surface...
of water more than hydrocarbon
Hydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons from which one hydrogen atom has been removed are functional groups, called hydrocarbyls....
surfactants while possessing exceptional stability due to the presence of multiple carbon–fluorine bond
Carbon–fluorine bond
The carbon–fluorine bond is a bond between carbon and fluorine that is a component of all organofluorine compounds. It is the strongest single bond in organic chemistry—and relatively short—due to its partial ionic character. The bond also strengthens and shortens as more fluorines are...
s. The stability of PFOA is desired industrially, but a cause of concern environmentally. PFOA is resistant to degradation by natural processes such as metabolism
Metabolism
Metabolism is the set of chemical reactions that happen in the cells of living organisms to sustain life. These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually divided into two categories...
, hydrolysis
Hydrolysis
Hydrolysis is a chemical reaction during which molecules of water are split into hydrogen cations and hydroxide anions in the process of a chemical mechanism. It is the type of reaction that is used to break down certain polymers, especially those made by condensation polymerization...
, photolysis, or biodegradation
Biodegradation
Biodegradation or biotic degradation or biotic decomposition is the chemical dissolution of materials by bacteria or other biological means...
making it persist indefinitely in the environment.
PFOA is found in environmental and biological fluids as the anion perfluorooctanoate. PFOA is absorbed from ingestion and can penetrate skin
Skin
-Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...
. The oxygens on PFOA are how it binds proteins with fatty acid
Fatty acid
In chemistry, especially biochemistry, a fatty acid is a carboxylic acid with a long unbranched aliphatic tail , which is either saturated or unsaturated. Most naturally occurring fatty acids have a chain of an even number of carbon atoms, from 4 to 28. Fatty acids are usually derived from...
or hormone
Hormone
A hormone is a chemical released by a cell or a gland in one part of the body that sends out messages that affect cells in other parts of the organism. Only a small amount of hormone is required to alter cell metabolism. In essence, it is a chemical messenger that transports a signal from one...
substrates such as serum albumin
Albumin
Albumin refers generally to any protein that is water soluble, which is moderately soluble in concentrated salt solutions, and experiences heat denaturation. They are commonly found in blood plasma, and are unique to other blood proteins in that they are not glycosylated...
, liver
Liver
The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...
fatty acid
Fatty acid
In chemistry, especially biochemistry, a fatty acid is a carboxylic acid with a long unbranched aliphatic tail , which is either saturated or unsaturated. Most naturally occurring fatty acids have a chain of an even number of carbon atoms, from 4 to 28. Fatty acids are usually derived from...
-binding protein, and the nuclear receptor
Nuclear receptor
In the field of molecular biology, nuclear receptors are a class of proteins found within cells that are responsible for sensing steroid and thyroid hormones and certain other molecules...
s PPARα
Peroxisome proliferator-activated receptor
In the field of molecular biology, the peroxisome proliferator-activated receptors are a group of nuclear receptor proteins that function as transcription factors regulating the expression of genes...
and possibly CAR
Constitutive androstane receptor
The constitutive androstane receptor also known as nuclear receptor subfamily 1, group I, member 3 is a protein that in humans is encoded by the NR1I3 gene...
. In animals, PFOA is mainly present in the liver
Liver
The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...
, blood
Blood
Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....
, and kidneys. PFOA does not accumulate in fat tissue, unlike traditional organohalogen persistent organic pollutants. In humans, PFOA has an average elimination half-life
Biological half-life
The biological half-life or elimination half-life of a substance is the time it takes for a substance to lose half of its pharmacologic, physiologic, or radiologic activity, as per the MeSH definition...
of about 3 years. Because of this long half-life, PFOA has the potential to bioaccumulate.
Global occurrence and sources
PFOA contaminates every continentContinent
A continent is one of several very large landmasses on Earth. They are generally identified by convention rather than any strict criteria, with seven regions commonly regarded as continents—they are : Asia, Africa, North America, South America, Antarctica, Europe, and Australia.Plate tectonics is...
. PFOA has been detected in the central Pacific Ocean at low parts per quadrillion ranges, and at low parts per trillion levels in coastal waters. 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
Surface water is water collecting on the ground or in a stream, river, lake, wetland, or ocean; it is related to water collecting as groundwater or atmospheric water....
s, and is present in numerous mammals, fish, and bird species. However, wildlife has much less PFOA than humans, unlike PFOS and other longer perfluorinated carboxylic acid
Perfluorinated carboxylic acid
Perfluorinated carboxylic acids , or perfluorocarboxylates are fully fluorinated organofluorine compounds—or perfluorinated compounds—with carboxylic acid or carboxylate functional groups. PFCAs are fluorocarbon derivatives...
s; in wildlife, PFOA is not as bioaccumulative as longer perfluorinated carboxylic acids.
Most industrialized nations have average PFOA blood serum
Blood serum
In blood, the serum is the component that is neither a blood cell nor a clotting factor; it is the blood plasma with the fibrinogens removed...
levels ranging from 2 to 8 parts per billion; the highest consumer sub-population identified was in Korea—with about 60 parts per billion. In Peru
Peru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....
, Vietnam
Vietnam
Vietnam – sometimes spelled Viet Nam , officially the Socialist Republic of Vietnam – is the easternmost country on the Indochina Peninsula in Southeast Asia. It is bordered by China to the north, Laos to the northwest, Cambodia to the southwest, and the South China Sea –...
, and Afghanistan
Afghanistan
Afghanistan , officially the Islamic Republic of Afghanistan, is a landlocked country located in the centre of Asia, forming South Asia, Central Asia and the Middle East. With a population of about 29 million, it has an area of , making it the 42nd most populous and 41st largest nation in the world...
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 is increasing in the blood of US consumers.
Industrial sources
PFOA is released directly from industrial sites. For example, the DuPont Washington Works facility in Washington, WV estimated total PFOA emissions of 80,000 pounds (lbsPound (mass)
The pound or pound-mass is a unit of mass used in the Imperial, United States customary and other systems of measurement...
) in 2000 and 1,700 pounds in 2004. A 2006 study, with two of four authors DuPont employees, estimated about 80% of historical perfluorocarboxylate emissions were released to the environment from fluoropolymer
Fluoropolymer
A fluoropolymer is a fluorocarbon based polymer with multiple strong carbon–fluorine bonds. It is characterized by a high resistance to solvents, acids, and bases.-History:Fluoropolymers were accidentally discovered in 1938 by Dr. Roy J...
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, paper and electronics industries.
The most important emission sources are carpet and textile protection as well as fire-fighting foams.
Precursors
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:...
(F(CF2)8CH2CH2OH), polyfluoroalkyl phosphate surfactants (PAPS), and possibly N-EtFOSE alcohol (F(CF2)8SO2N(Et)CH2CH2OH). When PTFE is degraded by heat (pyrolysis
Pyrolysis
Pyrolysis is a thermochemical decomposition of organic material at elevated temperatures without the participation of oxygen. It involves the simultaneous change of chemical composition and physical phase, and is irreversible...
) it can form PFOA as a minor product. The Organisation for Economic Co-operation and Development
Organisation for Economic Co-operation and Development
The Organisation for Economic Co-operation and Development is an international economic organisation of 34 countries founded in 1961 to stimulate economic progress and world trade...
(OECD) has compiled a list of 615 chemicals that have the potential to break down into perfluorocarboxylic acids
Perfluorinated carboxylic acid
Perfluorinated carboxylic acids , or perfluorocarboxylates are fully fluorinated organofluorine compounds—or perfluorinated compounds—with carboxylic acid or carboxylate functional groups. PFCAs are fluorocarbon derivatives...
(PFCA) including PFOA. However, not all 615 have the potential to break down to form PFOA.
A majority of waste water treatment plants (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
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, while others are under extended...
-based polymers; fluorotelomer alcohols attached to hydrocarbon backbones via ester
Ester
Esters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH group is replaced by an -O-alkyl group, and most commonly from carboxylic acids and...
linkages may detach and be free to biodegrade to PFOA.
Sources to people
FoodFood
Food is any substance consumed to provide nutritional support for the body. It is usually of plant or animal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals...
, drinking water
Drinking water
Drinking water or potable water is water pure enough to be consumed or used with low risk of immediate or long term harm. In most developed countries, the water supplied to households, commerce and industry is all of drinking water standard, even though only a very small proportion is actually...
, outdoor air, indoor air, dust
Dust
Dust consists of particles in the atmosphere that arise from various sources such as soil dust lifted up by wind , volcanic eruptions, and pollution...
, and food packaging
Food packaging
Food packaging is packaging for food. It requires protection, tampering resistance, and special physical, chemical, or biological needs. It also shows the product that is labeled to show any nutrition information on the food being consumed....
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.
Citizens that lived in the PFOA contaminated area around DuPont's Washington Works Washington, WV 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
Carbon filtering is a method of filtering that uses a piece of activated carbon to remove contaminants and impurities, utilizing chemical adsorption....
systems had lower PFOA levels.
Food contact surfaces
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, while others are under extended...
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
Lipophobicity, also sometimes called lipophobia, is a chemical property of chemical compounds which means "fat rejection", literally "fear of fat". Lipophobic compounds are those not soluble in lipids or other non-polar solvents...
: they prevent oil from soaking into the paper from fatty foods. Also, fluorotelomers can be metabolized into PFOA. In an U.S. Food and Drug Administration (USFDA) study, lipophobic 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, while microwave popcorn bags
Popcorn bag
A microwave popcorn bag is an engineered, enhanced, sealed paper bag in which un-popped popcorn is sold for the purpose of cooking popcorn in a microwave oven. These bags and their contents are sometimes referred to as microwave popcorn...
contained 6–290 parts per billion PFOA. 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. 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 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
Evaporation
Evaporation is a type of vaporization of a liquid that occurs only on the surface of a liquid. The other type of vaporization is boiling, which, instead, occurs on the entire mass of the liquid....
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 were detected in "very high" (low parts per million) levels in agricultural fields for grazing beef cattle and crops around Decatur, AL. The approximately 5000 acreAcre
The acre is a unit of area in a number of different systems, including the imperial and U.S. customary systems. The most commonly used acres today are the international acre and, in the United States, the survey acre. The most common use of the acre is to measure tracts of land.The acre is related...
s of land were fertilized with "treated municipal sewage sludge
Sludge
Sludge refers to the residual, semi-solid material left from industrial wastewater, or sewage treatment processes. It can also refer to the settled suspension obtained from conventional drinking water treatment, and numerous other industrial processes...
, or biosolids." PFOA was also detected in the blood of the cattle. The water treatment plant received process wastewater from a nearby perfluorochemical
Perfluorinated compounds
A perfluorinated compound is an organofluorine compound with all hydrogens replaced by fluorine on a carbon chain—but the molecule also contains at least one different atom or functional group. Thus, PFCs have properties similar to fluorocarbons as they are fluorocarbon derivatives...
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
United States Department of Agriculture
The United States Department of Agriculture is the United States federal executive department responsible for developing and executing U.S. federal government policy on farming, agriculture, and food...
reported—with a detection limits of 20 parts per billion—non-detectable levels for both PFOA and PFOS in cattle muscle tissue.
Drinking water and products
While there is no "legally enforceable federal standard" for the level of PFOA in drinking waterDrinking water
Drinking water or potable water is water pure enough to be consumed or used with low risk of immediate or long term harm. In most developed countries, the water supplied to households, commerce and industry is all of drinking water standard, even though only a very small proportion is actually...
in the US, on January 15, 2009, the Bush administration U.S. Environmental Protection Agency
United States Environmental Protection Agency
The U.S. Environmental Protection Agency is an agency of the federal government of the United States charged with protecting human health and the environment, by writing and enforcing regulations based on laws passed by Congress...
(USEPA) set a "provisional health advisory" of 0.4 parts per billion in response to the detection of PFOA in agricultural soil. However, the advisory is not meant to protect the public from long term exposure but might protect individuals for "a couple of years." While water companies are not required to test for PFOA, it is a potential candidate for regulation under the Safe Drinking Water Act
Safe Drinking Water Act
The Safe Drinking Water Act is the principle federal law in the United States intended to ensure safe drinking water for the public. Pursuant to the act, the Environmental Protection Agency is required to set standards for drinking water quality and oversee all states, localities, and water...
. As for consumer products, there is no federal safety standard for PFOA in the US.
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 CorbettEllen Corbett
Ellen Marie Corbett is a Democratic politician from San Leandro, California. She is currently serving her second term in the California State Senate. Corbett represents the 10th District, which includes San Leandro, Hayward, Pleasanton, Union City, Fremont, Newark, Milpitas and part of San Jose...
and the Environmental Working Group
Environmental Working Group
The Environmental Working Group is an American environmental organization that specializes in research and advocacy in the areas of toxic chemicals, agricultural subsidies, public lands, and corporate accountability...
, was approved that would have banned PFOA, PFOS, and related seven or more 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, and Schwarzenegger was lobbied by the chemical industry to veto. Schwarzenegger said the compound should be reviewed by the newly established, and more comprehensive, state program.
Fluorotelomers
Fluorotelomer-based products are under extended investigation to determine their potential to degrade to PFOA; these studies could lead the USEPA to require DuPont and others to reformulate products with a value over $1 billion.Toxicology data
PFOA is a carcinogenCarcinogen
A carcinogen is any substance, radionuclide, or radiation that is an agent directly involved in causing cancer. This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes...
, liver toxicant, a developmental toxicant, an immune system toxicant, and also exerts hormonal effects including alteration of thyroid hormone
Thyroid hormone
The thyroid hormones, thyroxine and triiodothyronine , are tyrosine-based hormones produced by the thyroid gland primarily responsible for regulation of metabolism. An important component in the synthesis of thyroid hormones is iodine. The major form of thyroid hormone in the blood is thyroxine ,...
levels. Animal studies show developmental toxicity from reduced birth size, physical developmental delays, endocrine disruption, and neonatal mortality
Perinatal mortality
Perinatal mortality , also perinatal death, 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 or exclusion of early fetal and...
. PFOA causes liver cancer
Liver cancer
Liver tumors or hepatic tumors are tumors or growths on or in the liver . Several distinct types of tumors can develop in the liver because the liver is made up of various cell types. These growths can be benign or malignant...
in rodents and also induces testicular
Testicular cancer
Testicular cancer is cancer that develops in the testicles, a part of the male reproductive system.In the United States, between 7,500 and 8,000 diagnoses of testicular cancer are made each year. In the UK, approximately 2,000 men are diagnosed each year. Over his lifetime, a man's risk of...
and pancreatic cancer
Pancreatic cancer
Pancreatic cancer refers to a malignant neoplasm of the pancreas. The most common type of pancreatic cancer, accounting for 95% of these tumors is adenocarcinoma, which arises within the exocrine component of the pancreas. A minority arises from the islet cells and is classified as a...
through induction of Leydig cell
Leydig cell
Leydig cells, also known as interstitial cells of Leydig, are found adjacent to the seminiferous tubules in the testicle. They produce testosterone in the presence of luteinizing hormone...
tumors and pancreatic acinar cell
Acinar cell
Acinar cell may refer to:* Centroacinar cells of the pancreas* Other acinus cells...
tumors. PFOA alters lipid metabolism
Lipid metabolism
Lipid metabolism refers to the processes that involve the intercourse and degradation of lipids.The types of lipids involved include:* Bile salts* Cholesterols* Eicosanoids* Glycolipids* Ketone bodies* Fatty acids - see also fatty acid metabolism...
. It is an agonist
Agonist
An agonist is a chemical that binds to a receptor of a cell and triggers a response by that cell. Agonists often mimic the action of a naturally occurring substance...
of PPARα
Peroxisome proliferator-activated receptor
In the field of molecular biology, the peroxisome proliferator-activated receptors are a group of nuclear receptor proteins that function as transcription factors regulating the expression of genes...
and is a peroxisome
Peroxisome
Peroxisomes are organelles found in virtually all eukaryotic cells. They are involved in the catabolism of very long chain fatty acids, branched chain fatty acids, D-amino acids, polyamines, and biosynthesis of plasmalogens, etherphospholipids critical for the normal function of mammalian brains...
proliferator in rodents contributing to a well understood form of oxidative stress
Oxidative stress
Oxidative stress represents an imbalance between the production and manifestation of reactive oxygen species and a biological system's ability to readily detoxify the reactive intermediates or to repair the resulting damage...
. Humans are considered less susceptible to peroxisome proliferation than rodents. However, PFOA has been found to be a liver carcinogen in rainbow trout
Rainbow trout
The rainbow trout is a species of salmonid native to tributaries of the Pacific Ocean in Asia and North America. The steelhead is a sea run rainbow trout usually returning to freshwater to spawn after 2 to 3 years at sea. In other words, rainbow trout and steelhead trout are the same species....
via a potential estrogenic mechanism, which may be more relevant to humans. A study found PFOA to be an obesogen
Obesogen
Obesogens are foreign chemical compounds that disrupt normal development and balance of lipid metabolism, which in some cases, can lead to obesity...
in female mice at mid-age—with altered levels of insulin
Insulin
Insulin is a hormone central to regulating carbohydrate and fat metabolism in the body. Insulin causes cells in the liver, muscle, and fat tissue to take up glucose from the blood, storing it as glycogen in the liver and muscle....
and leptin
Leptin
Leptin is a 16 kDa protein hormone that plays a key role in regulating energy intake and energy expenditure, including appetite and metabolism. It is one of the most important adipose derived hormones...
—at the lowest dose of 0.01 milligrams per kilogram of body weight during development.
While a USEPA review notes PFOA has not "been shown to be mutagenic in a variety of assays" in 1991 researchers from Japan demonstrated oxidative
Oxidative stress
Oxidative stress represents an imbalance between the production and manifestation of reactive oxygen species and a biological system's ability to readily detoxify the reactive intermediates or to repair the resulting damage...
liver DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
damage in an experiment with rats. 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
Genotoxic
In genetics, genotoxicity describes a deleterious action on a cell's genetic material affecting its integrity. This includes both certain chemical compounds and certain types of radiation....
via a peroxisome proliferation pathway that produced oxygen radicals
Reactive oxygen species
Reactive oxygen species are chemically reactive molecules containing oxygen. Examples include oxygen ions and peroxides. Reactive oxygen species are highly reactive due to the presence of unpaired valence shell electrons....
in HepG2 cells, and a 2006 study demonstrated the induction and suppression of a broad range of genes; therefore, it states that the indirect genotoxic (and thus carcinogenic) potential of PFOA cannot be dismissed. Criteria have been proposed that would allow PFOA, and other perfluorinated compounds, to be classified as "weakly non-specific genotoxic
Genotoxic
In genetics, genotoxicity describes a deleterious action on a cell's genetic material affecting its integrity. This includes both certain chemical compounds and certain types of radiation....
."
Human data
The levels of PFOA exposure in humans vary widely. While an average American might have 3 or 4 parts per billion of PFOA present in his blood serum, individuals occupationally exposed to PFOA have had blood serum levels over 100,000 parts per billion (100 parts per million or 0.01%) recorded. In a study of individuals living around DuPont's Washington Works WV plant, those who had no occupational exposure had a medianMedian
In probability theory and statistics, a median is described as the numerical value separating the higher half of a sample, a population, or a probability distribution, from the lower half. The median of a finite list of numbers can be found by arranging all the observations from lowest value to...
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.
Consumers
Single cross-sectional studiesCross-sectional study
Cross-sectional studies form a class of research methods that involve observation of all of a population, or a representative subset, at one specific point in time...
on consumers have been published noting multiple associations. Blood serum levels of PFOA were associated with an increased time to pregnancy—or "infertility
Infertility
Infertility primarily refers to the biological inability of a person to contribute to conception. Infertility may also refer to the state of a woman who is unable to carry a pregnancy to full term...
"—in a 2009 study. PFOA exposure was associated with decreased semen quality
Semen quality
Semen quality is a measure of the ability of semen to accomplish fertilization. Thus, it is a measure of fertility in a man. It is the sperm in the semen that are of importance, and therefore semen quality involves both sperm quantity and quality...
, increased serum alanine aminotransferase levels, and increased occurrence of thyroid disease
Thyroid disease
-Hyper- and hypofunction:Imbalance in production of thyroid hormones arises from dysfunction of the thyroid gland itself, the pituitary gland, which produces thyroid-stimulating hormone , or the hypothalamus, which regulates the pituitary gland via thyrotropin-releasing hormone . Concentrations of...
. In a study of 2003–2004 US samples, a higher (9.8 milligram per deciliter) total cholesterol level was observed when the highest quartile
Quartile
In descriptive statistics, the quartiles of a set of values are the three points that divide the data set into four equal groups, each representing a fourth of the population being sampled...
was compared to the lowest. Along with other related compounds, PFOA exposure was associated with an increased risk of attention deficit hyperactivity disorder (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 disruptor
Endocrine disruptors are chemicals that interfere with endocrine in animals, including humans. These disruptions can cause cancerous tumors, birth defects, and other developmental disorders...
by a potential mechanism on breast
Breast
The breast is the upper ventral region of the torso of a primate, in left and right sides, which in a female contains the mammary gland that secretes milk used to feed infants.Both men and women develop breasts from the same embryological tissues...
maturation in young girls. A C8 Science Panel status report noted an association between exposure in girls and a later onset of puberty
Puberty
Puberty is the process of physical changes by which a child's body matures into an adult body capable of reproduction, as initiated by hormonal signals from the brain to the gonads; the ovaries in a girl, the testes in a boy...
.
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. PFOA exposure in the Danish general population was not associated with an increased risk of prostate
Prostate cancer
Prostate cancer is a form of cancer that develops in the prostate, a gland in the male reproductive system. Most prostate cancers are slow growing; however, there are cases of aggressive prostate cancers. The cancer cells may metastasize from the prostate to other parts of the body, particularly...
, bladder
Bladder cancer
Bladder cancer is any of several types of malignant growths of the urinary bladder. It is a disease in which abnormal cells multiply without control in the bladder. The bladder is a hollow, muscular organ that stores urine; it is located in the pelvis...
, pancreatic
Pancreatic cancer
Pancreatic cancer refers to a malignant neoplasm of the pancreas. The most common type of pancreatic cancer, accounting for 95% of these tumors is adenocarcinoma, which arises within the exocrine component of the pancreas. A minority arises from the islet cells and is classified as a...
, or liver cancer
Liver cancer
Liver tumors or hepatic tumors are tumors or growths on or in the liver . Several distinct types of tumors can develop in the liver because the liver is made up of various cell types. These growths can be benign or malignant...
. 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 reviewLiterature review
A literature review is a body of text that aims to review the critical points of current knowledge including substantive findings as well as theoretical and methodological contributions to a particular topic...
of the epidemiological
Epidemiology
Epidemiology is the study of health-event, health-characteristic, or health-determinant patterns in a population. It is the cornerstone method of public health research, and helps inform policy decisions and evidence-based medicine by identifying risk factors for disease and targets for preventive...
evidence on PFOA exposure in Environmental Health Perspectives
Environmental Health Perspectives
Environmental Health Perspectives is a peer-reviewed open-access medical journal published monthly by the National Institute of Environmental Health Sciences. According to the Journal Citation Reports, the journal has a 2009 impact factor of 6.191....
. 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
Heart disease or cardiovascular disease are the class of diseases that involve the heart or blood vessels . While the term technically refers to any disease that affects the cardiovascular system , it is usually used to refer to those related to atherosclerosis...
is unknown. Further data on the 69,030 member cohort that is being studied by the panel is scheduled for release through 2012.
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, however, DuPont 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
Percentile
In statistics, a percentile is the value of a variable below which a certain percent of observations fall. For example, the 20th percentile is the value below which 20 percent of the observations may be found...
...based on 12 cases in the uppermost
category" which was deemed "suggestive of a possible relationship" between PFOA exposure and birth defects.
Industry and legal actions
DuPont has used PFOA for over 50 years at its Washington Works plant near Parkersburg, WV. 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 is paying for blood testBlood 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 needle, or via fingerprick....
s and health surveys
Biomonitoring
Aquatic biomonitoring is the science of inferring the ecological condition of rivers, lakes, streams, and wetlands by examining the organisms that live there...
of residents believed to be affected. Participants number 69,030 in the study, which will be reviewed by three epidemiologists
Epidemiology
Epidemiology is the study of health-event, health-characteristic, or health-determinant patterns in a population. It is the cornerstone method of public health research, and helps inform policy decisions and evidence-based medicine by identifying risk factors for disease and targets for preventive...
—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 will pay US$
United States dollar
The United States dollar , also referred to as the American dollar, is the official currency of the United States of America. It is divided into 100 smaller units called cents or pennies....
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
United States District Court for the Southern District of West Virginia
The United States District Court for the Southern District of West Virginia is a trial-level federal court. Decisions from the Court may be appealed to the Fourth Circuit Fourth Circuit, except for patent claims and claims against the U.S. government under the Tucker Act, which are appealed to...
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." On September 28, 2009, Judge Goodwin dismissed the claims of those residents except for medical monitoring.
U.S. federal government actions
In 2002, a panel of toxicologists, including several from the USEPA, proposed a level of 150 parts per billion for drinking waterDrinking water
Drinking water or potable water is water pure enough to be consumed or used with low risk of immediate or long term harm. In most developed countries, the water supplied to households, commerce and industry is all of drinking water standard, even though only a very small proportion is actually...
in the PFOA contaminated area around DuPont's Washington Works WV plant; this level was much higher than any known environmental concentration.
In July 2004, the USEPA filed a suit against DuPont alleging "widespread contamination" of PFOA near the Parkersburg, WV, 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 products.
On January 25, 2006, the USEPA announced a voluntary program with several chemical companies to reduce PFOA and PFOA precursor emissions by the year 2015.
On February 15, 2005, the USEPA's Science Advisory Board (SAB) voted to recommended that PFOA should be considered a "likely human carcinogen
Carcinogen
A carcinogen is any substance, radionuclide, or radiation that is an agent directly involved in causing cancer. This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes...
."
On May 26, 2006, the USEPA's SAB addressed a letter to Stephen L. Johnson
Stephen L. Johnson
Stephen L. Johnson was the Administrator of the Environmental Protection Agency under President George W. Bush during the second term of his administration...
. Three-quarters of advisers thought the stronger "likely to be carcinogenic" descriptor was warranted, in opposition to the USEPA's own PFOA hazard descriptor of "suggestive evidence of carcinogenicity, but not sufficient to assess human carcinogenic potential."
On November 21, 2006, the USEPA ordered DuPont company 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
Environmental Science & Technology , is a peer-reviewed scientific journal, published since 1967 by the American Chemical Society. As the name indicates, it publishes original research in environmental science, but also comprehensive, critical reviews. Publication is currently every other week...
Online article, U.S. Food and Drug Administration 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
Centers for Disease Control and Prevention
The Centers for Disease Control and Prevention are a United States federal agency under the Department of Health and Human Services headquartered in Druid Hills, unincorporated DeKalb County, Georgia, in Greater Atlanta...
(CDC) published data on PFOA concentrations comparing 1999–2000 vs. 2003–2004 NHANES
National Health and Nutrition Examination Survey
The National Health and Nutrition Examination Survey is a survey research program conducted by the National Center for Health Statistics to asses the health and nutritional status of adults and children in the United States, and to track changes over time. The survey combines interviews and...
samples.
On January 15, 2009, the USEPA set a provisional health advisory level of 0.4 parts per billion in drinking water.
U.S. state government actions
On February 13, 2007, the New Jersey Department of Environmental Protection issued a preliminary health-based guidance level of 0.04 parts per billion in drinking water, due to PFOA being found at "elevated levels in the system's drinking water near DuPont's massive Chambers Works chemical plant."On March 1, 2007, the Minnesota Department of Health lowered its Health Based Value for PFOA in drinking water from 1.0 parts per billion to 0.5 parts per billion, 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. The German Federal Environmental Agency issued guidelines for the sum of PFOA and PFOS 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."External links
- USEPA: PFOA and Fluorotelomer page
- USEPA: Links to related progams and studies
- Sustained Outrage Blog – C8 (PFOA) Category published by the Charleston Gazette
- 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