Perfluorooctanesulfonic acid (PFOS) (
conjugate base
A conjugate acid, within the Brønsted–Lowry acid–base theory, is a chemical compound formed when an acid gives a proton () to a base—in other words, it is a base with a hydrogen ion added to it, as it loses a hydrogen ion in the reve ...
perfluorooctanesulfonate) is a
chemical compound
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...
having an eight-
carbon
Carbon () is a chemical element; it has chemical symbol, symbol C and atomic number 6. It is nonmetallic and tetravalence, tetravalent—meaning that its atoms are able to form up to four covalent bonds due to its valence shell exhibiting 4 ...
fluorocarbon
Fluorocarbons are chemical compounds with carbon-fluorine bonds. Compounds that contain many C-F bonds often have distinctive properties, e.g., enhanced stability, volatility, and hydrophobicity. Several fluorocarbons and their derivatives are ...
chain and a
sulfonic acid
In organic chemistry, sulfonic acid (or sulphonic acid) refers to a member of the class of organosulfur compounds with the general formula , where R is an organic alkyl or aryl group and the group a sulfonyl hydroxide. As a substituent, it is kn ...
functional group
In organic chemistry, a functional group is any substituent or moiety (chemistry), moiety in a molecule that causes the molecule's characteristic chemical reactions. The same functional group will undergo the same or similar chemical reactions r ...
, and thus it is a
perfluorosulfonic acid and a
perfluoroalkyl substance (PFAS). It is an
anthropogenic
Anthropogenic ("human" + "generating") is an adjective that may refer to:
* Anthropogeny, the study of the origins of humanity
Anthropogenic may also refer to things that have been generated by humans, as follows:
* Human impact on the enviro ...
(man-made)
fluorosurfactant
Per- and polyfluoroalkyl substances (also PFAS, PFASs, and informally referred to as "forever chemicals") are a group of synthetic Organofluorine chemistry, organofluorine chemical compounds that have multiple fluorine atoms attached to an alkyl ...
, now regarded as a global
pollutant
A pollutant or novel entity is a substance or energy introduced into the environment that has undesired effect, or adversely affects the usefulness of a resource. These can be both naturally forming (i.e. minerals or extracted compounds like oi ...
. PFOS was the key ingredient in
Scotchgard
Scotchgard is a 3M brand of stain repellent and durable water repellent applied to fabrics, upholstery, and carpets to protect them from stains. Scotchgard products typically are based on organofluorine chemicals dissolved in a petroleum d ...
, a fabric protector made by
3M, and related stain repellents. The acronym "PFOS" refers to the parent sulfonic acid and to various
salts
In chemistry, a salt or ionic compound is a chemical compound consisting of an assembly of positively charged ions ( cations) and negatively charged ions (anions), which results in a compound with no net electric charge (electrically neutral). ...
of perfluorooctanesulfonate. These are all colorless or white, water-soluble solids. Although of low acute toxicity, PFOS has attracted much attention for its pervasiveness and environmental impact. It was added to Annex B of the
Stockholm Convention on Persistent Organic Pollutants
Stockholm Convention on Persistent Organic Pollutants is an international environmental treaty, signed on 22 May 2001 in Stockholm and effective from 17 May 2004, that aims to eliminate or restrict the production and use of persistent organi ...
in May 2009.
History
In 1949,
3M began producing PFOS-based compounds by
electrochemical fluorination.
In 1968,
organofluorine
Organofluorine chemistry describes the chemistry of organofluorine compounds, organic compounds that contain a carbon–fluorine bond. Organofluorine compounds find diverse applications ranging from Lipophobicity, oil and hydrophobe, water repell ...
compounds were detected in the
blood serum
Serum () is the fluid and solvent component of blood which does not play a role in clotting. It may be defined as blood plasma without the clotting factors, or as blood with all cells and clotting factors removed. Serum contains all proteins ex ...
of consumers, and in 1976,
perfluorooctanoic acid
Perfluorooctanoic acid (PFOA; conjugate acid, conjugate base perfluorooctanoate; also known colloquially as C8, from its chemical formula C8HF15O2) is a perfluorinated carboxylic acid produced and used worldwide as an industrial surfactant in ch ...
(PFOA) or a related compound such as PFOS were suggested as components.
In 1997, 3M detected PFOS in blood from global blood banks, although the company's internal documents indicate knowledge of this decades earlier, dating from the 1970s.
In 1999, the
U.S. Environmental Protection Agency began investigating
perfluorinated compounds
A perfluorinated compound (PFC) or perfluoro compound is an organofluorine compound that lacks C-H bonds. Many perfluorinated compounds have properties that are quite different from their C-H containing analogues. Common functional groups in PFCs ...
after receiving data on the global distribution and toxicity of PFOS, the key ingredient in
Scotchgard
Scotchgard is a 3M brand of stain repellent and durable water repellent applied to fabrics, upholstery, and carpets to protect them from stains. Scotchgard products typically are based on organofluorine chemicals dissolved in a petroleum d ...
. 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.
[3M]
"PFOS-PFOA Information: What is 3M Doing?"
Accessed October 25, 2008. Most other manufacturers (particularly, those in Europe) phased out the production of PFOS and
perfluorooctanoic acid
Perfluorooctanoic acid (PFOA; conjugate acid, conjugate base perfluorooctanoate; also known colloquially as C8, from its chemical formula C8HF15O2) is a perfluorinated carboxylic acid produced and used worldwide as an industrial surfactant in ch ...
(PFOA) in 2000 and 2006, respectively. A shorter-chain PFOS (
perfluorohexanesulfonic acid, PFHxS), was included in Annex A to the Stockholm Convention in 2022.
Currently, most of PFOS and PFOS-related chemicals are produced in China.
Chemistry
The main method used for the industrial scale production of PFOS is
electrochemical fluorination (ECF). ECF is an electrolysis method whereby the precursor of
octanesulfonyl fluoride is electrolyzed in a solution of hydrogen fluoride to give
perfluorooctanesulfonyl fluoride. This production method also results in shorter chain perfluoroalkyl substances being formed. PFOS predominates in the resultant mixture. A distinct isomer ratio has been observed in PFOS produced by ECF, in the order of 70% linear PFOS, 25% branched and 5% terminal; this is not a function of the production process but rather that the precursor also exhibits this isomer ratio. ECF was the means by which 3M produced PFOS up until May 2000 when the company announced a phaseout of
fluorosurfactant
Per- and polyfluoroalkyl substances (also PFAS, PFASs, and informally referred to as "forever chemicals") are a group of synthetic Organofluorine chemistry, organofluorine chemical compounds that have multiple fluorine atoms attached to an alkyl ...
s.
Although 89
constitutional isomers of PFOS are possible, environmental samples usually consist of a mixture of the linear isomer and 10 branched isomers.
Telomerisation involves constructing the PFOS molecule using short chain (often 2-carbon) precursors and adding a sulfonate group as a final step. This production process results in 100% linear PFOS. This production method, whilst cleaner and resulting in a much purer product than ECF, is not known to have been widely used except for the production of reagent grade PFOS and analytical standards.
Indirect routes
Perfluorooctylsulfonyl compounds degrade to PFOS. Examples include (''N''-MeFOSE), a
carpet
A carpet is a textile floor covering typically consisting of an upper layer of Pile (textile), pile attached to a backing. The pile was traditionally made from wool, but since the 20th century synthetic fiber, synthetic fibres such as polyprop ...
stain repellent, and (''N''-EtFOSE), a
paper
Paper is a thin sheet material produced by mechanically or chemically processing cellulose fibres derived from wood, Textile, rags, poaceae, grasses, Feces#Other uses, herbivore dung, or other vegetable sources in water. Once the water is dra ...
treatment. Also
perfluorooctanesulfonamide is a precursor.
About 50 precursors were named in the 2004 proposed
Canadian
Canadians () are people identified with the country of Canada. This connection may be residential, legal, historical or cultural. For most Canadians, many (or all) of these connections exist and are collectively the source of their being ''C ...
ban on PFOS.
Degradation
PFOS virtually does not degrade under environmental conditions and is thus highly persistent.
Waste water treatment plant
Water treatment is any process that improves the quality of water to make it appropriate for a specific end-use. The end use may be drinking, industrial water supply, irrigation, river flow maintenance, water recreation or many other uses, inc ...
s are also unable to degrade PFOS. On the other hand, precursors are transformed to PFOS in waste water treatment plants.
Properties
The C
8F
17 subunit of PFOS is
hydrophobic
In chemistry, hydrophobicity is the chemical property of a molecule (called a hydrophobe) that is seemingly repelled from a mass of water. In contrast, hydrophiles are attracted to water.
Hydrophobic molecules tend to be nonpolar and, thu ...
and
lipophobic
Lipophobicity, also sometimes called lipophobia (from the Greek λιποφοβία from λίπος ''lipos'' "fat" and φόβος ''phobos'' "fear"), is a chemical property of chemical compounds which means "fat rejection", literally "fear of fat" ...
, like other
fluorocarbons
Fluorocarbons are chemical compounds with carbon-fluorine bonds. Compounds that contain many C-F bonds often have distinctive properties, e.g., enhanced stability, volatility, and hydrophobicity. Several fluorocarbons and their derivatives are ...
, while the
sulfonic acid
In organic chemistry, sulfonic acid (or sulphonic acid) refers to a member of the class of organosulfur compounds with the general formula , where R is an organic alkyl or aryl group and the group a sulfonyl hydroxide. As a substituent, it is kn ...
/
sulfonate
In organosulfur chemistry, a sulfonate is a salt, anion or ester of a sulfonic acid. Its formula is , containing the functional group , where R is typically an organyl group, amino group or a halogen atom. Sulfonates are the conjugate bases of ...
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
The carbon–fluorine bond is a polar covalent bond between carbon and fluorine that is a component of all organofluorine compounds. It is one of the strongest single bonds in chemistry (after the B–F single bond, Si–F single bond, and H–F ...
s. PFOS is a
fluorosurfactant
Per- and polyfluoroalkyl substances (also PFAS, PFASs, and informally referred to as "forever chemicals") are a group of synthetic Organofluorine chemistry, organofluorine chemical compounds that have multiple fluorine atoms attached to an alkyl ...
that lowers the
surface tension
Surface tension is the tendency of liquid surfaces at rest to shrink into the minimum surface area possible. Surface tension (physics), tension is what allows objects with a higher density than water such as razor blades and insects (e.g. Ge ...
of water more than that of
hydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and Hydrophobe, hydrophobic; their odor is usually fain ...
surfactant
Surfactants are chemical compounds that decrease the surface tension or interfacial tension between two liquids, a liquid and a gas, or a liquid and a solid. The word ''surfactant'' is a Blend word, blend of "surface-active agent",
coined in ...
s.
Uses
Perfluorooctanesulfonic acid was usually used as the sodium or potassium
salts
In chemistry, a salt or ionic compound is a chemical compound consisting of an assembly of positively charged ions ( cations) and negatively charged ions (anions), which results in a compound with no net electric charge (electrically neutral). ...
.
* PFOS was the key ingredient in
Scotchgard
Scotchgard is a 3M brand of stain repellent and durable water repellent applied to fabrics, upholstery, and carpets to protect them from stains. Scotchgard products typically are based on organofluorine chemicals dissolved in a petroleum d ...
, a fabric protector made by
3M, and numerous stain repellents.
* PFOS, together with
PFOA
Perfluorooctanoic acid (PFOA; conjugate base perfluorooctanoate; also known colloquially as C8, from its chemical formula C8HF15O2) is a perfluorinated carboxylic acid produced and used worldwide as an industrial surfactant in chemical process ...
, has also been used to make ''
aqueous film forming foam'' (AFFF), a component of
fire-fighting foams, and
alcohol-type concentrate foams.
* PFOS compounds can also be 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
semiconductor
A semiconductor is a material with electrical conductivity between that of a conductor and an insulator. Its conductivity can be modified by adding impurities (" doping") to its crystal structure. When two regions with different doping level ...
industry, PFOS is used in multiple
photolithographic
Photolithography (also known as optical lithography) is a process used in the manufacturing of integrated circuits. It involves using light to transfer a pattern onto a substrate, typically a silicon wafer.
The process begins with a photosensit ...
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.
* PFOS is the key ingredient in
Skydrol, a fire-resistant
hydraulic fluid
A hydraulic fluid or hydraulic liquid is the medium by which power is transferred in hydraulic machinery. Common hydraulic fluids are based on mineral oil or water. Examples of equipment that might use hydraulic fluids are excavators and backho ...
used in
commercial aviation
Commercial aviation is the part of civil aviation that involves operating aircraft for remuneration or hire, as opposed to private aviation.
Definition
Commercial aviation is not a rigorously defined category. All commercial air transport and ae ...
.
The most important emission sources of PFOS have been metal plating and fire-fighting foams. Because of concerns about PFOS,
F-53B has been used as a replacement for mist suppression in metal plating.
Levels in humans
Because of its chemical properties, PFOS will remain in the body for several years. It is estimated that it takes 4 years for half of this substance to be eliminated from the body.
PFOS is detected in the
blood serum
Serum () is the fluid and solvent component of blood which does not play a role in clotting. It may be defined as blood plasma without the clotting factors, or as blood with all cells and clotting factors removed. Serum contains all proteins ex ...
of almost all people in the U.S., but concentrations have been decreasing over time. In contrast, PFOS blood levels appear to be rising in China where PFOS production continues. A study of ca. 2000 teenagers from 9 European countries with most samples collected in years 2016-2018 found higher blood concentrations of several PFOS’s in those, who consumed more seafood, eggs or
offal
Offal (), also called variety meats, pluck or organ meats, is the internal organ (anatomy), organs of a butchered animal. Offal may also refer to the by-products of Milling (grinding), milled grains, such as corn or wheat.
Some cultures strong ...
, as well as in those from North and West (versus the South and East) Europe. Within the same country, boys had a higher PFOS concentrations than girls. A typical PFOS blood concentration range in this study was 1,500–2,500
ppb.
Much higher levels of blood PFOS (12,830
ppb) have been reported in people with occupational exposure —or possibly 1,656 parts per billion—in a consumer. Occupationally exposed individuals may 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 may be over the 91.5 parts per billion level.
PFOS exposure has been demonstrated as early as fetal development during pregnancy since PFOS can easily pass through the
placenta
The placenta (: placentas or placentae) is a temporary embryonic and later fetal organ that begins developing from the blastocyst shortly after implantation. It plays critical roles in facilitating nutrient, gas, and waste exchange between ...
.
It has been shown that fetal exposure to PFOS is quite prevalent and has been shown to be detected in greater than 99% of
umbilical cord
In Placentalia, placental mammals, the umbilical cord (also called the navel string, birth cord or ''funiculus umbilicalis'') is a conduit between the developing embryo or fetus and the placenta. During prenatal development, the umbilical cord i ...
serum samples.
PFOS has been detected in U.S.
freshwater fish
Freshwater fish are fish species that spend some or all of their lives in bodies of fresh water such as rivers, lakes, ponds and inland wetlands, where the salinity is less than 1.05%. These environments differ from marine habitats in many wa ...
, as well as in municipal wastewater and drinking water samples, worldwide, at concentrations ranging between few ng/L and some μg/L.
Levels in wildlife
A variety of
wildlife
Wildlife refers to domestication, undomesticated animals and uncultivated plant species which can exist in their natural habitat, but has come to include all organisms that grow or live wilderness, wild in an area without being species, introdu ...
species have had PFOS levels measured in
egg
An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the ...
,
liver
The liver is a major metabolic organ (anatomy), organ exclusively found in vertebrates, which performs many essential biological Function (biology), functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of var ...
,
kidney
In humans, the kidneys are two reddish-brown bean-shaped blood-filtering organ (anatomy), organs that are a multilobar, multipapillary form of mammalian kidneys, usually without signs of external lobulation. They are located on the left and rig ...
,
serum, and
plasma samples and some of the highest recorded values as of January 2006 are listed below.
[Supporting Information]
(PDF).
Despite the global wide-ranging restriction, PFOS concentrations in air continued to increase at many monitoring stations between 2009 and 2017.
Health effects in humans and wildlife
There is a growing body of research investigating the health effects of PFOS in humans and animals, including the reproductive, developmental, liver, kidney, thyroid, and immunological effects.
According to a 2002 report by the Environmental Directorate of the
OECD
The Organisation for Economic Co-operation and Development (OECD; , OCDE) is an international organization, intergovernmental organization with 38 member countries, founded in 1961 to stimulate economic progress and international trade, wor ...
, "PFOS is
persistent, bioaccumulative, and toxic to mammalian species."
Pregnancy outcomes
Several studies have focused on pregnancy outcomes in infants and mothers who are exposed to PFOS during pregnancy. For developing offspring, exposure to PFOS occurs through the placenta.
While the impact of PFOS compounds on fetal development continues to be an ongoing investigation, findings have demonstrated a relationship between PFOS exposure in pregnant mothers and negative birth outcomes.
There has been some evidence to suggest that PFOS levels in pregnant women have been associated with
preeclampsia
Pre-eclampsia is a multi-system disorder specific to pregnancy, characterized by the new onset of high blood pressure and often a significant amount of protein in the urine or by the new onset of high blood pressure along with significant end- ...
,
preterm labor
Preterm birth, also known as premature birth, is the birth of a baby at fewer than 37 weeks gestational age, as opposed to full-term delivery at approximately 40 weeks. Extreme preterm is less than 28 weeks, very early preterm birth is between ...
,
low birth weight
Low birth weight (LBW) is defined by the World Health Organization as a birth weight of an infant of or less, regardless of gestational age. Infants born with LBW have added health risks which require close management, often in a neonatal inten ...
and
gestational diabetes
Gestational diabetes is a condition in which a woman without diabetes develops hyperglycemia, high blood sugar levels during pregnancy. Gestational diabetes generally results in few symptoms. Obesity increases the rate of pre-eclampsia, cesarea ...
.
Although, the strongest association is between PFOS levels with preterm birth and preeclampsia.
There has been some evidence to suggest that PFOS impairs fetal growth during pregnancy, although findings have been inconsistent.
The specific physiological mechanisms behind adverse pregnancy outcomes with PFOS exposure remain unclear. One proposed cause has to do with PFOS impairment on placental blood flow.
This mechanism could help explain several of the pregnancy-related outcomes from PFOS exposure including such as intrauterine growth development, low birth weight, preterm birth labor, and preeclampsia. Additional physiological mechanisms may include disruption in inflammatory signals during pregnancy, decreased trophoblast signaling and trophoblast migration. Additionally, PFOS exposure has been shown to be related to the downregulation genes corresponding to growth factors, pregnancy-related signal transducers, and maternal hormones. PFOS impact on thyroid hormone regulation also has the potential to impact several birth outcomes.
Breastfeeding and lactation
PFOS has been measured in breastmilk and is estimated to contribute the greatest level of PFOS exposure in infants. Specifically, the duration of breastfeeding has been shown to be associated with increases in PFOS in infants. Some evidence has shown that breastmilk accounts for more than 94% of the PFOS exposure in infants up to six months old. The Agency for Toxic Substances and Disease Registry (ATSDR) concluded that breastfeeding benefits continue to outweigh potential risks associated with PFOS in breastmilk.
Thyroid disease
Increased levels of PFOS have been shown to accumulate in
thyroid
The thyroid, or thyroid gland, is an endocrine gland in vertebrates. In humans, it is a butterfly-shaped gland located in the neck below the Adam's apple. It consists of two connected lobes. The lower two thirds of the lobes are connected by ...
gland cells and have been associated with altered
thyroid hormone
File:Thyroid_system.svg, upright=1.5, The thyroid system of the thyroid hormones triiodothyronine, T3 and T4
rect 376 268 820 433 Thyroid-stimulating hormone
rect 411 200 849 266 Thyrotropin-releasing hormone
rect 297 168 502 200 Hypothalamus
r ...
levels in adults.
Appropriate levels of thyroid hormone during pregnancy are critical for a developing fetus as this hormone is involved with brain development and body growth. Studies have demonstrated a relationship between PFOS exposure and thyroid dysfunction during pregnancy resulting in altered thyroid hormone levels in both the mother and the fetus.
Hypercholesterolemia
PFOS has been associated with increased risk of abnormal levels of
cholesterol
Cholesterol is the principal sterol of all higher animals, distributed in body Tissue (biology), tissues, especially the brain and spinal cord, and in Animal fat, animal fats and oils.
Cholesterol is biosynthesis, biosynthesized by all anima ...
.
Specifically,
epidemiological studies
Epidemiology is the study and analysis of the distribution (who, when, and where), patterns and determinants of health and disease conditions in a defined population, and application of this knowledge to prevent diseases.
It is a cornerstone ...
in humans have reported an association between increased PFOS levels and the total cholesterol and
low density lipoprotein
Low-density lipoprotein (LDL) is one of the five major groups of lipoprotein that transport all fat molecules around the body in extracellular water. These groups, from least dense to most dense, are chylomicrons (aka ULDL by the overall densit ...
(LDL) cholesterol.
Chronic kidney disease
Serum levels of PFOS were found to be associated with increased risk of
chronic kidney disease
Chronic kidney disease (CKD) is a type of long-term kidney disease, defined by the sustained presence of abnormal kidney function and/or abnormal kidney structure. To meet criteria for CKD, the abnormalities must be present for at least three mo ...
in the general US population.
"This
association was independent of
confounders such as age, sex, race/ethnicity,
body mass index
Body mass index (BMI) is a value derived from the mass (Mass versus weight, weight) and height of a person. The BMI is defined as the human body weight, body mass divided by the square (algebra), square of the human height, body height, and is ...
, diabetes, hypertension, and serum cholesterol level."
Cancer
Research demonstrating the association between PFOS and cancer is still ongoing. A few studies have demonstrated an elevated risk for prostate and bladder cancer, however, there were notable limitations in the design and analysis of these studies.
As of November 2023, the
International Agency for Research on Cancer
The International Agency for Research on Cancer (IARC; ) is an intergovernmental agency forming part of the World Health Organization of the United Nations.
Its role is to conduct and coordinate research into the causes of cancer. It also cance ...
(IARC) has classified PFOS as possibly carcinogenic to humans (Group 2b) based on “strong” mechanistic evidence. The Division of Cancer Epidemiology & Genetics (DCEG) is currently investigating the association of several PFAS compounds and cancers including kidney cancer, testicular cancer, prostate cancer, ovarian and endometrial cancer, thyroid cancer, non-hodgkins lymphoma, and childhood leukemia.
In wildlife
The levels observed in wild animals are considered sufficient to "alter health parameters".
PFOS affects the
immune system
The immune system is a network of biological systems that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to bacteria, as well as Tumor immunology, cancer cells, Parasitic worm, parasitic ...
of male mice at a
blood serum
Serum () is the fluid and solvent component of blood which does not play a role in clotting. It may be defined as blood plasma without the clotting factors, or as blood with all cells and clotting factors removed. Serum contains all proteins ex ...
concentration of 91.5
parts per billion
In science and engineering, the parts-per notation is a set of pseudo-units to describe the small values of miscellaneous dimensionless quantities, e.g. mole fraction or mass fraction.
Since these fractions are quantity-per-quantity measur ...
, raising the possibility that highly exposed people and wildlife are
immunocompromised
Immunodeficiency, also known as immunocompromise, is a state in which the immune system's ability to fight infectious diseases and cancer is compromised or entirely absent. Most cases are acquired ("secondary") due to extrinsic factors that affe ...
.
Chicken eggs dosed at 1 milligram per kilogram (or 1 part per million) of egg weight developed into juvenile chickens with an average of ~150 parts per billion in blood serum—and showed brain asymmetry and decreased
immunoglobulin
An antibody (Ab) or immunoglobulin (Ig) is a large, Y-shaped protein belonging to the immunoglobulin superfamily which is used by the immune system to identify and neutralize antigens such as pathogenic bacteria, bacteria and viruses, includin ...
levels.
Regulation
Globally
It was added to Annex B of the
Stockholm Convention on Persistent Organic Pollutants
Stockholm Convention on Persistent Organic Pollutants is an international environmental treaty, signed on 22 May 2001 in Stockholm and effective from 17 May 2004, that aims to eliminate or restrict the production and use of persistent organi ...
in May 2009.
Originally, parties agreed on acceptable proposes (time-unlimited exemptions) for the following uses—in addition to a range of specific exemptions (time-limited):
* Photo-imaging
* Photo-resist and anti-reflective coatings for semi-conductors
*
Etching
Etching is traditionally the process of using strong acid or mordant to cut into the unprotected parts of a metal surface to create a design in intaglio (incised) in the metal. In modern manufacturing, other chemicals may be used on other type ...
agent for compound semi-conductors and ceramic filters
* Aviation hydraulic fluids
*
Metal plating
Plating is a finishing process in which a metal is deposited on a surface. Plating has been done for hundreds of years; it is also critical for modern technology. Plating is used to decorate objects, for corrosion inhibition, to improve solderab ...
(hard metal plating) only in closed-loop systems
* Certain medical devices (such as ethylene tetrafluoroethylene copolymer (
ETFE
Ethylene tetrafluoroethylene (ETFE) is a fluorine-based plastic. It was designed to have high corrosion resistance and strength over a wide temperature range. ETFE is a polymer and its source-based name is poly (ethene-co-tetrafluoroethene). It i ...
) layers and radio-opaque ETFE production, in-vitro diagnostic medical devices, and CCD colour filters)
*
Fire-fighting foam
Firefighting foam is a foam used for fire suppression systems, fire suppression. Its role is to cool the fire and to coat the fuel, preventing its contact with oxygen, thus achieving suppression of the combustion. Firefighting foam was invented b ...
* Insect baits for control of leaf-cutting ants from ''
Atta spp.'' and ''
Acromyrmex
''Acromyrmex'' is a genus of New World ants of the subfamily Myrmicinae. This genus is found in South America and parts of Central America, México and the Caribbean Islands, and contains 33 known species.
Commonly known as " leafcutter ants" th ...
spp.''
In 2019, it was decided to only keep one acceptable purpose:
* Insect baits with
sulfluramid (CAS No. 4151-50-2) as an active ingredient for control of leaf-cutting ants from ''Atta'' spp. and ''Acromyrmex'' spp. for agricultural use only
Canada
In 2023, the Government of Canada is considering addressing PFAS as a class rather than as individual substances or in smaller groups. A report to conclude that PFAS as a class are harmful to human health and the environment, and to define risk management aspects and alternatives to PFAs, is under developmen
"Per-and polyfluoroalkyl substances (PFAS)"
Europe
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). However, PFOS use 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 the summer of 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).
United States
In 2018 the
State of Michigan
Michigan ( ) is a peninsular U.S. state, state in the Great Lakes region, Great Lakes region of the Upper Midwest, Upper Midwestern United States. It shares water and land boundaries with Minnesota to the northwest, Wisconsin to the west, ...
established a legally enforceable groundwater cleanup level of 70 ppt for both PFOA and PFOS.
In 2020 the
Michigan Department of Environment, Great Lakes, and Energy
The Michigan Department of Environment, Great Lakes, and Energy (EGLE), formerly Michigan Department of Environmental Quality (Michigan DEQ, MDEQ, or simply DEQ), is a principal department of the U.S. state of Michigan for environmental issues. T ...
(EGLE) adopted stricter drinking water standards in the form of
maximum contaminant level
Maximum contaminant levels (MCLs) are standards that are set by the United States Environmental Protection Agency (EPA) for drinking water quality.Joseph Cotruvo, Victor Kimm, Arden Calvert“Drinking Water: A Half Century of Progress.”EPA Alumn ...
s (MCLs), lowering acceptable levels from the 2018 enforceable groundwater cleanup levels of 70 ppt to 8 ppt for PFOA and 16 ppt for PFOS and adding MCLs for 5 previously unregulated PFAS compounds
PFNA
Perfluorononanoic acid, or PFNA, is a synthetic perfluorinated carboxylic acid and fluorosurfactant that is also a persistent organic pollutant.
Chemistry and properties
In acidic form it is a highly reactive strong acid. In its conjugate base for ...
,
PFHxA,
PFHxS,
PFBS, and
HFPO-DA.
In 2020, a California bill was passed banning PFOS and the following salts as an intentionally added ingredient from cosmetics: ammonium perfluorooctane sulfonate, diethanolamine perfluorooctane sulfonate, lithium perfluorooctane sulfonate and potassium perfluorooctane sulfonate.
In March 2021 the U.S. EPA announced that it will develop national drinking water standards for PFOA and PFOS.
In October 2021 the EPA proposed to designate PFOA and PFOS as hazardous substances in its PFAS Strategic Roadmap.
[Docke]
EPA-HQ-OLEM-2019-0341
/ref> In September 2022 the EPA proposed to designate as hazardous substances under the Superfund
Superfund is a United States federal environmental remediation program established by the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA). The program is administered by the United States Environmental Pro ...
Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA).
See also
*2005 Hertfordshire Oil Storage Terminal fire
5 (five) is a number, numeral and digit. It is the natural number, and cardinal number, following 4 and preceding 6, and is a prime number.
Humans, and many other animals, have 5 digits on their limbs.
Mathematics
5 is a Fermat pri ...
*Fluorocarbon
Fluorocarbons are chemical compounds with carbon-fluorine bonds. Compounds that contain many C-F bonds often have distinctive properties, e.g., enhanced stability, volatility, and hydrophobicity. Several fluorocarbons and their derivatives are ...
s
*Per- and polyfluoroalkyl substances
Per- and polyfluoroalkyl substances (also PFAS, PFASs, and informally referred to as "forever chemicals") are a group of synthetic organofluorine chemical compounds that have multiple fluorine atoms attached to an alkyl chain; there are 7 milli ...
* Timeline of events related to per- and polyfluoroalkyl substances
References
External links
*
Mason Chemical Company, Fluorosurfactant Structure/Function page
PFOS risk assessment report
Centers for Disease Control and Prevention, Polyfluorochemicals fact sheet
Perfluorinated substances and their uses in Sweden
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
{{Authority control
Anionic surfactants
Persistent organic pollutants under the Stockholm Convention
Endocrine disruptors
Perfluorosulfonic acids