Perfluorooctanesulfonic acid (PFOS) (

conjugate base A conjugate acid, within the Brønsted–Lowry acid–base theory, is a chemical compound formed when an acid donates a proton () to a base—in other words, it is a base with a hydrogen ion added to it, as in the reverse reaction it loses a ...

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 with the symbol C and atomic number 6. It is nonmetallic and tetravalent—its atom making four electrons available to form covalent chemical bonds. It belongs to group 14 of the periodic table. Carbon ma ...

fluorocarbon Fluorocarbons are chemical compounds with carbon-fluorine bonds. Compounds that contain many C-F bonds often has distinctive properties, e.g., enhanced stability, volatility, and hydrophobicity. Fluorocarbons and their derivatives are commerci ...

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 k ...

functional group In organic chemistry, a functional group is a substituent or moiety in a molecule that causes the molecule's characteristic chemical reactions. The same functional group will undergo the same or similar chemical reactions regardless of the r ...

and thus a perfluorosulfonic acid. It is an

anthropogenic Anthropogenic ("human" + "generating") is an adjective that may refer to: * Anthropogeny, the study of the origins of humanity Counterintuitively, anthropogenic may also refer to things that have been generated by humans, as follows: * Human i ...

(man-made)

fluorosurfactant Per- and polyfluoroalkyl substances (PFASs) are synthetic organofluorine chemical compounds that have multiple fluorine atoms attached to an alkyl chain. An early definition, from 2011, required that they contain at least one perfluoroalkyl ...

, now regarded as a global

pollutant A pollutant or novel entity is a substance or energy introduced into the environment that has undesired effects, or adversely affects the usefulness of a resource. These can be both naturally forming (i.e. minerals or extracted compounds like o ...

. PFOS was the key ingredient in

Scotchgard Scotchgard is a 3M brand of products, a stain and durable water repellent applied to fabric, furniture, and carpets to protect them from stains. Scotchgard products typically rely on organofluorine chemicals as the main active ingredient along w ...

, 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 is a chemical compound consisting of an ionic assembly of positively charged cations and negatively charged anions, which results in a compound with no net electric charge. A common example is table salt, with positively c ...

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 Electrochemical fluorination (ECF), or electrofluorination, is a foundational organofluorine chemistry method for the preparation of fluorocarbon-based organofluorine compounds.G. Siegemund, W. Schwertfeger, A. Feiring, B. Smart, F. Behr, H. Vogel, ...

resulting in the synthetic precursor

perfluorooctanesulfonyl fluoride Perfluorooctanesulfonyl fluoride (POSF) is a synthetic perfluorinated compound with a sulfonyl fluoride functional group. It is used to make perfluorooctanesulfonic acid (PFOS) and PFOS-based compounds. These compounds have a variety of industr ...

. In 1968,

organofluorine Organofluorine chemistry describes the chemistry of the organofluorines, organic compounds that contain the carbon–fluorine bond. Organofluorine compounds find diverse applications ranging from oil and water repellents to pharmaceuticals, r ...

content was detected in the

blood serum Serum () is the fluid and solute component of blood which does not play a role in clotting. It may be defined as blood plasma without the clotting factors, or as blood with all cells and clotting factors removed. Serum includes all proteins not ...

of consumers, and in 1976 it was suggested to be

perfluorooctanoic acid Perfluorooctanoic acid (PFOA; conjugate base perfluorooctanoate; also known colloquially as C8, for its 8 carbon chain structure) is a perfluorinated carboxylic acid produced and used worldwide as an industrial surfactant in chemical processes a ...

(PFOA) or a related compound such as PFOS. 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 containing only carbon-fluorines and C−C bonds, as well as potentially heteroatoms. Perfluorinated compounds have properties that result from the presence of flu ...

after receiving data on the global distribution and toxicity of PFOS, the key ingredient in

. 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. PFOS and PFOS-related chemicals are currently produced in China.

Chemistry

The main method used for the industrial scale production of PFOS is electrochemical fluorination (ECF). ECF is an electrolysis production method where a precursor of

is dispersed in a solution of hydrogen fluoride and electrolyzed. This production method, whilst economic and mainly results in PFOS, also results in shorter chain perfluoroalkyl substances being formed. PFOS predominates in the resultant mixture, however, if the reaction is allowed to continue this begins to favor the production of shorter chain PFAS. 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

s. 89 constitutional isomers of PFOS are theoretically possible, environmental samples usually contain 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 more pure 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''-methyl perfluorooctane sulfonamidoethanol (''N''-MeFOSE), a

carpet A carpet is a textile floor covering typically consisting of an upper layer of pile attached to a backing. The pile was traditionally made from wool, but since the 20th century synthetic fibers such as polypropylene, nylon, or polyester ...

stain repellent, and ''N''-ethyl perfluorooctane sulfonamidoethanol (''N''-EtFOSE), a

paper Paper is a thin sheet material produced by mechanically or chemically processing cellulose fibres derived from wood, rags, grasses or other vegetable sources in water, draining the water through fine mesh leaving the fibre evenly distribu ...

treatment. Also perfluorooctanesulfonamide is a precursor. About 50 precursors were named in the 2004 proposed

Canadian Canadians (french: Canadiens) 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 ...

ban on PFOS.

Degradation

PFOS does virtually not degrade under environmental conditions and is thus highly persistent. Waste water treatment plants are also unable to degrade PFOS. On the other hand, precursors are transformed to PFOS in waste water treatment plants.

Properties

The C₈F₁₇ subunit of PFOS is

hydrophobic In chemistry, hydrophobicity is the physical property of a molecule that is seemingly repelled from a mass of water (known as a hydrophobe). In contrast, hydrophiles are attracted to water. Hydrophobic molecules tend to be nonpolar and, ...

and lipophobic, like other

fluorocarbons Fluorocarbons are chemical compounds with carbon-fluorine bonds. Compounds that contain many C-F bonds often has distinctive properties, e.g., enhanced stability, volatility, and hydrophobicity. Fluorocarbons and their derivatives are commerci ...

, while the

/ 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 bonds. PFOS is a

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 is what allows objects with a higher density than water such as razor blades and insects (e.g. water striders) t ...

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 hydrophobic, and their odors are usually weak or ...

surfactant Surfactants are chemical compounds that decrease the surface tension between two liquids, between a gas and a liquid, or interfacial tension between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsion#Emulsifiers , ...

Uses

Perfluorooctanesulfonic acid is usually used as the sodium or potassium

. * PFOS was the key ingredient in

, a fabric protector made by 3M, and numerous stain repellents. * PFOS, together with PFOA, 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 which has an electrical conductivity value falling between that of a conductor, such as copper, and an insulator, such as glass. Its resistivity falls as its temperature rises; metals behave in the opposite way ...

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. * PFOS is the key ingredient in

Skydrol Skydrol is a fire-resistant aviation hydraulic fluid manufactured by Solutia (now part of Eastman Chemical Company), and formerly manufactured by Monsanto. There are various lines of Skydrol including Skydrol 500B-4, Skydrol LD-4, and Skydrol 5. Sk ...

, 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 backhoe ...

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 ...

. The most important emission sources of PFOS are 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 nature, 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

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. In people, the highest exposures to PFOS in blood have been 12,830 parts per billion for occupational exposure and 656 parts per billion—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 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 the physically separate mate ...

. 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 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 is physiologi ...

serum samples. PFOS has been detected 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 undomesticated animal species, but has come to include all organisms that grow or live wild in an area without being introduced by humans. Wildlife was also synonymous to game: those birds and mammals that were hunted ...

species have had PFOS levels measured in egg,

liver The liver is a major organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the synthesis of proteins and biochemicals necessary for digestion and growth. In humans, it i ...

kidney The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; blo ...

serum Serum may refer to: * Serum (blood), plasma from which the clotting proteins have been removed **Antiserum, blood serum with specific antibodies for passive immunity * Serous fluid, any clear bodily fluid *Truth serum, a drug that is likely to mak ...

, and plasma samples and some of the highest recorded values as of January 2006 are listed below.Supporting Information
(PDF).

Health effects in humans and wildlife

There has been a growing body of evidence investigating the health effects of PFOS on the reproductive, developmental, liver, kidney, thyroid, and immunological effects in humans.

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 disorder of pregnancy characterized by the onset of high blood pressure and often a significant amount of protein in the urine. When it arises, the condition begins after 20 weeks of pregnancy. In severe cases of the disease ...

, preterm labor,

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 int ...

and

gestational diabetes Gestational diabetes is a condition in which a woman without diabetes develops high blood sugar levels during pregnancy. Gestational diabetes generally results in few symptoms; however, it increases the risk of pre-eclampsia, depression, and ...

. 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 provides 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.

Infertility

PFAS compounds such as PFOS act as an endocrine disruptor of the reproductive system. As such, there is concern over the impact of this compound on fertility. There is some evidence to suggest that PFOS may impair fertility in both females and males. One study found that women with higher levels of PFOS and PFOA took longer to become pregnant than those with lower levels, suggesting that the chemicals may impair fertility. The impact of PFOS on male fertility is still under investigation. There have been some studies that demonstrated that PFOS is associated with a decrease in sperm count and as well as a decrease in the number of morphologically normal sperm. There has also been evidence to suggest that PFOS may also reduce

testosterone Testosterone is the primary sex hormone and anabolic steroid in males. In humans, testosterone plays a key role in the development of male reproductive tissues such as testes and prostate, as well as promoting secondary sexual characteristi ...

levels.

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 in the neck and consists of two connected lobes. The lower two thirds of the lobes are connected by a thin band of tissue called the thyroid isthmus. The ...

gland cells and have been associated with altered

thyroid hormone File:Thyroid_system.svg, upright=1.5, The thyroid system of the thyroid hormones T3 and T4 rect 376 268 820 433 Thyroid-stimulating hormone rect 411 200 849 266 Thyrotropin-releasing hormone rect 297 168 502 200 Hypothalamus rect 66 216 386 25 ...

levels 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 any of a class of certain organic molecules called lipids. It is a sterol (or modified steroid), a type of lipid. Cholesterol is biosynthesized by all animal cells and is an essential structural component of animal cell memb ...

. 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. It is a cornerstone of public health, and shapes policy decisions and evid ...

in humans have reported an association between increased PFOS levels and the total cholesterol and low density lipoprotein (LDL) cholesterol.

ADHD

Levels of PFOS in US children aged 12–15 were associated with an increased risk (60% over the

interquartile range In descriptive statistics, the interquartile range (IQR) is a measure of statistical dispersion, which is the spread of the data. The IQR may also be called the midspread, middle 50%, fourth spread, or H‑spread. It is defined as the differen ...

) of

attention deficit hyperactivity disorder Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterised by excessive amounts of inattention, hyperactivity, and impulsivity that are pervasive, impairing in multiple contexts, and otherwise age-inap ...

(ADHD). The importance of exposure timing during development is unclear, however, some evidence has shown that exposure to PFOS during fetal development was not associated with an increased risk for developing of ADHD later in childhood.

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 kidney disease in which a gradual loss of kidney function occurs over a period of months to years. Initially generally no symptoms are seen, but later symptoms may include leg swelling, feeling tired, vo ...

in the general US population. "This association was independent of

confounders In statistics, a confounder (also confounding variable, confounding factor, extraneous determinant or lurking variable) is a variable that influences both the dependent variable and independent variable, causing a spurious association. Con ...

such as age, sex, race/ethnicity,

body mass index Body mass index (BMI) is a value derived from the mass ( weight) and height of a person. The BMI is defined as the body mass divided by the square of the body height, and is expressed in units of kg/m2, resulting from mass in kilograms and ...

, diabetes, hypertension, and serum cholesterol level." According to a 2002 study by the Environmental Directorate of the

OECD The Organisation for Economic Co-operation and Development (OECD; french: Organisation de coopération et de développement économiques, ''OCDE'') is an intergovernmental organisation with 38 member countries, founded in 1961 to stimulate ...

, "PFOS is persistent, bioaccumulative, and toxic to mammalian species."

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. PFOA, another long-chain PFAS compound, has been classified as "possibly carcinogenic to humans" (class 2b) by the International Agency for Research on Cancer (IARC) based on evidence demonstrating an association with testicular and kidney cancer. 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 processes that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to parasitic worms, as well as cancer cells and objects such as wood splinte ...

of male mice at a

concentration of 91.5

parts per billion In science and engineering, the parts-per notation is a set of pseudo-units to describe small values of miscellaneous dimensionless quantities, e.g. mole fraction or mass fraction. Since these fractions are quantity-per-quantity measures, th ...

, raising the possibility that highly exposed people and wildlife are immunocompromised. 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), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of th ...

levels.

Regulation

Globally

It was added to Annex B of the

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 types ...

agent for compound semi-conductors and ceramic filters * Aviation hydraulic fluids * Metal plating (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 is ...

) layers and radio-opaque ETFE production, in-vitro diagnostic medical devices, and CCD colour filters) * Fire-fighting foam * 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 and the Caribbean Islands, and contains 33 known species. Commonly known as "leafcutter ants" they compris ...

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 2008 Canada proposed a ban on PFOS, only the second chemical proposed for a complete ban under the ''

Canadian Environmental Protection Act The ''Canadian Environmental Protection Act, 1999'' (''CEPA, 1999''; french: Loi canadienne sur la protection de l'environnement (1999)) is an act of the 36th Parliament of Canada, whose goal is to contribute to sustainable development through p ...

''.

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 Reach or REACH may refer to: Companies and organizations * Reach plc, formerly Trinity Mirror, large British newspaper, magazine, and digital publisher * Reach Canada, an NGO in Canada * Reach Limited, an Asia Pacific cable network company ...

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 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 levels (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 an environmental contaminant found in people and wildlife along with PFOS and PFOA. Chemistry and properties In acidic form it is a h ...

, PFHxA, PFHxS,

PFBS Perfluorobutanesulfonic acid (PFBS) is a chemical compound having a four-carbon fluorocarbon chain and a sulfonic acid functional group. It is stable and unreactive because of the strength of carbon–fluorine bonds. It can occur in the form of ...

, and HFPO-DA. 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 Environmental Protection Agency ...

Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA).

References

External links

*
Mason Chemical Company, Fluorosurfactant Structure/Function pagePFOS risk assessment reportCenters for Disease Control and Prevention, Polyfluorochemicals fact sheetPerfluorinated substances and their uses in SwedenChain of Contamination: The Food Link, Perfluorinated Chemicals (PFCs) Incl. PFOS & PFOAProvisional 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