Perfluorooctane sulfonate
Encyclopedia
Perfluorooctanesulfonic acid (PFOA), or perfluorooctane sulfonate(PFOS), is a man-made fluorosurfactant
and global pollutant
. PFOS was the key ingredient in Scotchgard
, a fabric protector made by 3M
, and numerous stain repellents. It was added to Annex B of the Stockholm Convention on Persistent Organic Pollutants
in May 2009. PFOS can form from the degradation of precursors in addition to industrial production. The PFOS levels that have been detected in wildlife are considered high enough to affect health parameters, and recently higher serum levels of PFOS 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."
began producing PFOS-based compounds by electrochemical fluorination
resulting in the synthetic precursor perfluorooctane sulfonyl fluoride. 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 1997, 3M detected PFOS in blood from global blood banks. In 1999, the U.S. Environmental Protection Agency
began investigating perfluorinated compounds
after receiving data on the global distribution and toxicity of PFOS, the key ingredient in Scotchgard
. For these reasons, and USEPA pressure, the primary American producer of PFOS, 3M
, announced, in May 2000, the phaseout of the production of PFOS, PFOA
, and PFOS-related products. PFOS and PFOS-related chemicals are currently produced in China
.
Advances in analytical chemistry
in recent years have allowed the routine detection of low- and sub-ppb levels of PFOS in food, wildlife, and humans.
/sulfonate
group adds polarity. PFOS is an exceptionally stable compound in industrial applications and in the environment because of the effect of aggregate carbon–fluorine bond
s. PFOS is a fluorosurfactant
that lowers the surface tension
of water more than that of hydrocarbon
surfactant
s. Although attention is typically focused on the straight-chain isomer (n-PFOS), which is dominant in commercial mixtures and environmental samples, there are 89 linear and branched congeners that are expected to have different physical, chemical, and toxicological properties.
The most important emission sources of PFOS are metal plating and fire-fighting foams.
It has been shown to affect the immune system
of male mice at a blood serum
concentration of ~90 parts per billion, raising the possibility that highly exposed people and wildlife are immunocompromised. Chicken eggs dosed at 1 milligram per kilogram (or 1000 parts per billion) of egg weight developed into juvenile chickens with an average of ~150 parts per billion in blood serum—and showed effects such as brain asymmetry and decreased immunoglobulin levels. Occupationally exposed individuals have an average level of PFOS over 1000 parts per billion, and a small segment of individuals in the upper range of the general population are also over the 91.5 parts per billion level. A variety of wildlife
species have had PFOS levels measured in egg
, liver
, kidney
, serum
, and plasma
samples and some of the highest recorded values as of January 2006 are listed below.
The levels observed in wild animals are considered sufficient to "alter health parameters". In people, the highest exposures to PFOS in blood are 12,830 parts per billion for occupational exposure and 656 parts per billion—or possibly 1,656 parts per billion—in a consumer.
In animal studies PFOS also causes cancer
, physical development delays, endocrine disruption, and neonatal mortality; neonatal mortality might be the most dramatic result of laboratory animal tests with PFOS. Female mice with blood levels of PFOS within ranges found in wildlife and humans demonstrated higher mortality when infected with influenza A. PFOS reduces the birth size of animals; in humans, correlations between PFOS levels and reduced fetal growth are inconsistent.
PFOS is detected in the blood serum
of almost all people in the U.S., where concentrations are decreasing; by contrast, blood levels of PFOS appear to be rising in China
. PFOS levels in pregnant women have been associated with preeclampsia. Levels have also been associated with altered thyroid hormone
values and an increased risk of high cholesterol
. Levels in US children aged 12–15 were associated with an increased risk (60% over the interquartile range
) of attention deficit hyperactivity disorder (ADHD).
sulfonamide
PFOS precursors include N-methyl perfluorooctane sulfonamidoethanol (N-MeFOSE), a carpet
stain repellent, and N-ethyl perfluorooctane sulfonamidoethanol (N-EtFOSE), a paper
treatment. Perfluorooctanesulfonamide
is a precursor. About 50 precursors were named in the 2004 proposed Canadian
ban on PFOS.
by the Fourth Conference of Parties. Canada
has a proposed ban on PFOS, only the second chemical proposed for a complete ban under the Canadian Environmental Protection Act
.
Based on an OECD study on PFOS and a risk assessment by Europe's Scientific Committee on Health and Environmental Risks the European Union practically banned the use of PFOS in finished and semi-finished products in 2006 (maximum content of PFOS: 0.005% by weight). Use of PFOS for industrial applications (e.g. photolithography, mist suppressants for hard chromium plating, hydraulic fluids for aviation) was exempted.
In 2009 this directive was incorporated into the REACH regulation. In summer 2010 PFOS was added to the regulation on persistent organic pollutants and the threshold was lowered to max. 0.001% by weight (10 mg/kg).
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...
and global pollutant
Pollutant
A pollutant is a waste material that pollutes air, water or soil, and is the cause of pollution.Three factors determine the severity of a pollutant: its chemical nature, its concentration and its persistence. Some pollutants are biodegradable and therefore will not persist in the environment in the...
. PFOS was the key ingredient in Scotchgard
Scotchgard
Scotchgard is a 3M brand of products used to protect fabric, furniture, and carpets from stains.The original formula for Scotchgard was discovered accidentally in 1952 by 3M chemists Patsy Sherman and Samuel Smith...
, a fabric protector made by 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....
, and numerous stain repellents. It was added to Annex B of the Stockholm Convention on Persistent Organic Pollutants
Stockholm Convention on Persistent Organic Pollutants
Stockholm Convention on Persistent Organic Pollutants is an international environmental treaty, signed in 2001 and effective from May 2004, that aims to eliminate or restrict the production and use of persistent organic pollutants .- History :...
in May 2009. PFOS can form from the degradation of precursors in addition to industrial production. The PFOS levels that have been detected in wildlife are considered high enough to affect health parameters, and recently higher serum levels of PFOS 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."
History
In 1949, 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 PFOS-based compounds 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...
resulting in the synthetic precursor perfluorooctane sulfonyl fluoride. 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
Perfluorooctanoic acid
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...
or a related compound such as PFOS. In 1997, 3M detected PFOS in blood from global blood banks. In 1999, the 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...
began investigating perfluorinated compounds
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...
after receiving data on the global distribution and toxicity of PFOS, the key ingredient in Scotchgard
Scotchgard
Scotchgard is a 3M brand of products used to protect fabric, furniture, and carpets from stains.The original formula for Scotchgard was discovered accidentally in 1952 by 3M chemists Patsy Sherman and Samuel Smith...
. For these reasons, and USEPA pressure, the primary American producer of PFOS, 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....
, announced, in May 2000, the phaseout of the production of PFOS, PFOA
Perfluorooctanoic acid
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...
, and PFOS-related products. PFOS and PFOS-related chemicals are currently produced in China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
.
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-ppb levels of PFOS in food, wildlife, and humans.
Properties
The C8F17 subunit of PFOS is hydrophobic and lipophobic, like other fluorocarbons, while the sulfonic acidSulfonic acid
Sulfonic acid usually refers to a member of the class of organosulfur compounds with the general formula RS2–OH, where R is an alkyl or aryl. The formal part of acid, HS2–OH, are formally derivatives of the "parent" inorganic compound with the formula HSO2.-Preparation:Sulfonic acid is...
/sulfonate
Sulfonate
A sulfonate is a salt or ester of a sulfonic acid. It contains the functional group R-SO2O-.- Sulfonate salts:Anions with the general formula RSO2O− are called sulfonates. They are the conjugate bases of sulfonic acids with formula RSO2OH. As sulfonic acids tend to be strong acids, the...
group adds polarity. PFOS is an exceptionally stable compound in industrial applications and in the environment because of the effect of aggregate 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. PFOS is a 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...
that lowers 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 that of 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....
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...
s. Although attention is typically focused on the straight-chain isomer (n-PFOS), which is dominant in commercial mixtures and environmental samples, there are 89 linear and branched congeners that are expected to have different physical, chemical, and toxicological properties.
Uses
Perfluorooctanesulfonic acid is usually used as the sodium or potassium salts.- PFOS was the key ingredient in ScotchgardScotchgardScotchgard is a 3M brand of products used to protect fabric, furniture, and carpets from stains.The original formula for Scotchgard was discovered accidentally in 1952 by 3M chemists Patsy Sherman and Samuel Smith...
, a fabric protector made by 3M3M3M Company , formerly known as the Minnesota Mining and Manufacturing Company, is an American multinational conglomerate corporation based in Maplewood, Minnesota, United States....
, and numerous stain repellents. - PFOS, together with PFOAPerfluorooctanoic acidPerfluorooctanoic 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...
, has also been used to make aqueous film forming foam (AFFF), a component of fire-fighting foamsFire retardant foamFire-fighting foam is a foam used for fire suppression. Its role is to cool the fire and to coat the fuel, preventing its contact with oxygen, resulting in suppression of the combustion. Fire-fighting foam was invented by the Russian engineer and chemist Aleksandr Loran in 1902.The surfactants used...
, and alcohol-type concentrate foams. - PFOS compounds can be also found in some impregnation agents for textiles, paper, and leather; in wax, polishes, paints, varnishes, and cleaning products for general use; in metal surfaces, and carpets.
- In the semiconductorSemiconductorA semiconductor is a material with electrical conductivity due to electron flow intermediate in magnitude between that of a conductor and an insulator. This means a conductivity roughly in the range of 103 to 10−8 siemens per centimeter...
industry, PFOS is used in multiple photolithographic chemicals including: photoacid generators (PAGs) and anti-reflective coatings (ARCs). It has been phased out in the European Union semiconductor industry due to health concerns. - In SkydrolSkydrolSkydrol is an advanced fire resistant aviation hydraulic fluid manufactured by Solutia Inc. There are various lines of Skydrol including Skydrol 500B-4, Skydrol LD-4, and Skydrol 5....
, a hydraulic fluidHydraulic fluidHydraulic fluids, also called hydraulic liquids, are the medium by which power is transferred in hydraulic machinery. Common hydraulic fluids are based on mineral oil or water...
used in commercial aviationCommercial aviationCommercial aviation is the part of civil aviation that involves operating aircraft for hire to transport passengers or cargo...
.
The most important emission sources of PFOS are metal plating and fire-fighting foams.
Threat to people and wildlife
According to a study by the Environmental Directorate of the OECD "PFOS is persistent, bioaccumulative and toxic to mammalian species."It has been shown to affect the immune system
Immune system
An immune system is a system of biological structures and processes within an organism that protects against disease by identifying and killing pathogens and tumor cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own...
of male mice at a 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...
concentration of ~90 parts per billion, raising the possibility that highly exposed people and wildlife are immunocompromised. Chicken eggs dosed at 1 milligram per kilogram (or 1000 parts per billion) of egg weight developed into juvenile chickens with an average of ~150 parts per billion in blood serum—and showed effects such as brain asymmetry and decreased immunoglobulin levels. Occupationally exposed individuals have an average level of PFOS over 1000 parts per billion, and a small segment of individuals in the upper range of the general population are also over the 91.5 parts per billion level. A variety of wildlife
Wildlife
Wildlife includes all non-domesticated plants, animals and other organisms. Domesticating wild plant and animal species for human benefit has occurred many times all over the planet, and has a major impact on the environment, both positive and negative....
species have had PFOS levels measured in egg
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
, 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...
, kidney
Kidney
The kidneys, organs with several functions, serve essential regulatory roles in most animals, including vertebrates and some invertebrates. They are essential in the urinary system and also serve homeostatic functions such as the regulation of electrolytes, maintenance of acid–base balance, and...
, 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...
, and plasma
Blood plasma
Blood plasma is the straw-colored liquid component of blood in which the blood cells in whole blood are normally suspended. It makes up about 55% of the total blood volume. It is the intravascular fluid part of extracellular fluid...
samples and some of the highest recorded values as of January 2006 are listed below.
| Species | Geography | Year | Sample | PFOS (ppb) |
|---|---|---|---|---|
| Bald Eagle Bald Eagle The Bald Eagle is a bird of prey found in North America. It is the national bird and symbol of the United States of America. This sea eagle has two known sub-species and forms a species pair with the White-tailed Eagle... |
Midwestern USA | 1990–93 | plasma | 2,200 |
| Brandt's Cormorant Brandt's Cormorant The Brandt's Cormorant is a strictly marine bird of the cormorant family of seabirds that inhabits the Pacific coast of North America. It ranges, in the summer, from Alaska to the Gulf of California, but the population north of Vancouver Island migrates south during the winter... |
California California California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area... , USA |
1997 | liver | 970 |
| Guillemot Guillemot Guillemots is the common name for several species of seabird in the auk family . In British use, the term comprises two genera: Uria and Cepphus. In North America the Uria species are called "murres" and only the Cepphus species are called "guillemots"... |
Baltic Sea Baltic Sea The Baltic Sea is a brackish mediterranean sea located in Northern Europe, from 53°N to 66°N latitude and from 20°E to 26°E longitude. It is bounded by the Scandinavian Peninsula, the mainland of Europe, and the Danish islands. It drains into the Kattegat by way of the Øresund, the Great Belt and... |
1997 | egg | 614 |
| Carrion Crow Carrion Crow The Carrion Crow is a member of the passerine order of birds and the crow family which is native to western Europe and eastern Asia.-Taxonomy:... |
Tokyo Bay Tokyo Bay is a bay in the southern Kantō region of Japan. Its old name was .-Geography:Tokyo Bay is surrounded by the Bōsō Peninsula to the east and the Miura Peninsula to the west. In a narrow sense, Tokyo Bay is the area north of the straight line formed by the on the Miura Peninsula on one end and on... , Japan Japan Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south... |
2000 | liver | 464 |
| Red-throated Loon | North Carolina North Carolina North Carolina is a state located in the southeastern United States. The state borders South Carolina and Georgia to the south, Tennessee to the west and Virginia to the north. North Carolina contains 100 counties. Its capital is Raleigh, and its largest city is Charlotte... , USA |
1998 | liver | 861 |
| Polar Bear Polar Bear The polar bear is a bear native largely within the Arctic Circle encompassing the Arctic Ocean, its surrounding seas and surrounding land masses. It is the world's largest land carnivore and also the largest bear, together with the omnivorous Kodiak Bear, which is approximately the same size... |
Sanikiluaq, Nunavut Nunavut Nunavut is the largest and newest federal territory of Canada; it was separated officially from the Northwest Territories on April 1, 1999, via the Nunavut Act and the Nunavut Land Claims Agreement Act, though the actual boundaries had been established in 1993... |
2002 | liver | 3,100 |
| Harbor Seal Harbor Seal The harbor seal , also known as the common seal, is a true seal found along temperate and Arctic marine coastlines of the Northern Hemisphere... |
Dutch Wadden Sea, Denmark Denmark Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark... |
2002 | muscle | 2,725 |
| Bottlenose Dolphin Bottlenose Dolphin Bottlenose dolphins, the genus Tursiops, are the most common and well-known members of the family Delphinidae, the family of oceanic dolphins. Recent molecular studies show the genus contains two species, the common bottlenose dolphin and the Indo-Pacific bottlenose dolphin , instead of one... |
Charleston, South Carolina Charleston, South Carolina Charleston is the second largest city in the U.S. state of South Carolina. It was made the county seat of Charleston County in 1901 when Charleston County was founded. The city's original name was Charles Towne in 1670, and it moved to its present location from a location on the west bank of the... , USA |
2003 | plasma | 1,315 |
| Common Dolphin Common dolphin The common dolphin is the name given to two species of dolphin making up the genus Delphinus.Prior to the mid-1990s, most taxonomists only recognised one species in this genus, the common dolphin Delphinus delphis... |
Mediterranean Sea Mediterranean Sea The Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant... , Italy Italy Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and... |
1998 | liver | 940 |
| Mink Mink There are two living species referred to as "mink": the European Mink and the American Mink. The extinct Sea Mink is related to the American Mink, but was much larger. All three species are dark-colored, semi-aquatic, carnivorous mammals of the family Mustelidae, which also includes the weasels and... |
Michigan Michigan Michigan is a U.S. state located in the Great Lakes Region of the United States of America. The name Michigan is the French form of the Ojibwa word mishigamaa, meaning "large water" or "large lake".... , USA |
2000–01 | liver | 59,500 |
The levels observed in wild animals are considered sufficient to "alter health parameters". In people, the highest exposures to PFOS in blood are 12,830 parts per billion for occupational exposure and 656 parts per billion—or possibly 1,656 parts per billion—in a consumer.
In animal studies PFOS also causes cancer
Cancer
Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...
, physical development delays, endocrine disruption, and neonatal mortality; neonatal mortality might be the most dramatic result of laboratory animal tests with PFOS. Female mice with blood levels of PFOS within ranges found in wildlife and humans demonstrated higher mortality when infected with influenza A. PFOS reduces the birth size of animals; in humans, correlations between PFOS levels and reduced fetal growth are inconsistent.
PFOS is 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 almost all people in the U.S., where concentrations are decreasing; by contrast, blood levels of PFOS appear to be rising in China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
. PFOS levels in pregnant women have been associated with preeclampsia. Levels have also been associated with altered 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 ,...
values and an increased risk of high 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...
. Levels in US children aged 12–15 were associated with an increased risk (60% over the interquartile range
Interquartile range
In descriptive statistics, the interquartile range , also called the midspread or middle fifty, is a measure of statistical dispersion, being equal to the difference between the upper and lower quartiles...
) of attention deficit hyperactivity disorder (ADHD).
Precursors
VolatileVolatility (chemistry)
In chemistry and physics, volatility is the tendency of a substance to vaporize. Volatility is directly related to a substance's vapor pressure. At a given temperature, a substance with higher vapor pressure vaporizes more readily than a substance with a lower vapor pressure.The term is primarily...
sulfonamide
Sulfonamide (chemistry)
In chemistry, the sulfonamide functional group is -S2-NH2, a sulfonyl group connected to an amine group.A sulfonamide is a compound that contains this group. The general formula is RSO2NH2, where R is some organic group. For example, "methanesulfonamide" is CH3SO2NH2...
PFOS precursors include N-methyl perfluorooctane sulfonamidoethanol (N-MeFOSE), a 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...
stain repellent, and N-ethyl perfluorooctane sulfonamidoethanol (N-EtFOSE), a paper
Paper
Paper is a thin material mainly used for writing upon, printing upon, drawing or for packaging. It is produced by pressing together moist fibers, typically cellulose pulp derived from wood, rags or grasses, and drying them into flexible sheets....
treatment. Perfluorooctanesulfonamide
Perfluorooctanesulfonamide
Perfluorooctanesulfonamide is a synthetic organofluorine compound. It is a fluorocarbon derivative, or perfluorinated compound, with eight carbons and a terminal sulfonamide functional group. PFOSA was an ingredient in 3M's former Scotchgard formulation and the compound was used to repel grease...
is a precursor. About 50 precursors were named in the 2004 proposed Canadian
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
ban on PFOS.
Regulatory Status
In May 2009 PFOS was included in Annex B of the Stockholm Convention on persistent organic pollutantsStockholm Convention on Persistent Organic Pollutants
Stockholm Convention on Persistent Organic Pollutants is an international environmental treaty, signed in 2001 and effective from May 2004, that aims to eliminate or restrict the production and use of persistent organic pollutants .- History :...
by the Fourth Conference of Parties. Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
has a proposed ban on PFOS, only the second chemical proposed for a complete ban under the Canadian Environmental Protection Act
Canadian Environmental Protection Act
The Canadian Environmental Protection Act of 1999 is "An Act respecting pollution prevention and the protection of the environment and human health in order to contribute to sustainable development."...
.
Based on an OECD study on PFOS and a risk assessment by Europe's Scientific Committee on Health and Environmental Risks the European Union practically banned the use of PFOS in finished and semi-finished products in 2006 (maximum content of PFOS: 0.005% by weight). Use of PFOS for industrial applications (e.g. photolithography, mist suppressants for hard chromium plating, hydraulic fluids for aviation) was exempted.
In 2009 this directive was incorporated into the REACH regulation. In summer 2010 PFOS was added to the regulation on persistent organic pollutants and the threshold was lowered to max. 0.001% by weight (10 mg/kg).
External links
- Mason Chemical Company, Fluorosurfactant Structure/Function page
- PFOS risk assessment report
- The Environmental Working Group, PFC page
- Centers for Disease Control and Prevention, Polyfluorochemicals fact sheet
- Perfluorinated substances and their uses in Sweden
- Perfluoroalkylated substances, Aquatic environmental assessment
- Chain of Contamination: The Food Link, Perfluorinated Chemicals (PFCs) Incl. PFOS & PFOA
- Provisional evaluation of PFT in drinking water with the guide substances perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) as examples
- OECD Hazard Assessment