Perfluorooctanesulfonamide (PFOSA) is a synthetic

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

. It is a

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 ...

derivative and a

perfluorinated compound A perfluorinated compound (PFC) or perfluoro compound is an Organofluorine chemistry, organofluorine compound that lacks C-H bonds. Many perfluorinated compounds have properties that are quite different from their C-H containing analogues. Common ...

, having an eight-carbon chain and a terminal

sulfonamide In organic chemistry, the sulfonamide functional group (also spelled sulphonamide) is an organosulfur group with the Chemical structure, structure . It consists of a sulfonyl group () connected to an amine group (). Relatively speaking this gro ...

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 ...

. PFOSA, a

persistent organic pollutant Persistent organic pollutants (POPs) are organic compounds that are resistant to degradation through chemical, biological, and photolytic processes. They are toxic and adversely affect human health and the environment around the world. Because ...

, was an ingredient in 3M's former

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 ...

formulation from 1956 until 2003, and the compound was used to repel grease and water in food packaging along with other consumer applications. It breaks down to form

perfluorooctane sulfonate Perfluorooctanesulfonic acid (PFOS) (conjugate base perfluorooctanesulfonate) is a chemical compound having an eight-carbon fluorocarbon chain and a sulfonic acid functional group, and thus it is a perfluorosulfonic acid and a perfluoroalkyl sub ...

(PFOS). PFOSA can be synthesized via the

nucleophilic substitution In chemistry, a nucleophilic substitution (SN) is a class of chemical reactions in which an electron-rich chemical species (known as a nucleophile) replaces a functional group within another electron-deficient molecule (known as the electrophile) ...

of POSF with liquid

ammonia Ammonia is an inorganic chemical compound of nitrogen and hydrogen with the chemical formula, formula . A Binary compounds of hydrogen, stable binary hydride and the simplest pnictogen hydride, ammonia is a colourless gas with a distinctive pu ...

or by a two step reaction via an

azide In chemistry, azide (, ) is a linear, polyatomic anion with the formula and structure . It is the conjugate base of hydrazoic acid . Organic azides are organic compounds with the formula , containing the azide functional group. The dominant ...

followed by reduction with Zn and HCl. PFOSA is also a metabolic by-product of ''N''-alkylated perfluorooctanesulfonamides. For example, ''N''-ethyl perfluorooctanesulfonamidoethanol (''N''-EtFOSE), which was primarily used on paper, and ''N''-methyl perfluorooctanesulfonamidoethanol (''N''-MeFOSE), which was primarily used on carpets and textiles, both metabolize via

acetate An acetate is a salt formed by the combination of acetic acid with a base (e.g. alkaline, earthy, metallic, nonmetallic, or radical base). "Acetate" also describes the conjugate base or ion (specifically, the negatively charged ion called ...

s to PFOSA. In addition, PFOSA is thought to be the biologically active form of the

insecticide Insecticides are pesticides used to kill insects. They include ovicides and larvicides used against insect eggs and larvae, respectively. The major use of insecticides is in agriculture, but they are also used in home and garden settings, i ...

Sulfluramid (''N''-ethyl perfluorooctanesulfonamide) as it is an extremely potent

uncoupler An uncoupler or uncoupling agent is a molecule that disrupts oxidative phosphorylation in prokaryotes and mitochondria or photophosphorylation in chloroplasts and cyanobacteria by dissociating the reactions of ATP synthesis from the electron trans ...

oxidative phosphorylation Oxidative phosphorylation(UK , US : or electron transport-linked phosphorylation or terminal oxidation, is the metabolic pathway in which Cell (biology), cells use enzymes to Redox, oxidize nutrients, thereby releasing chemical energy in order ...

with an IC₅₀ of about 1

micromolar Molar concentration (also called molarity, amount concentration or substance concentration) is the number of moles of solute per liter of solution. Specifically, It is a measure of the concentration of a chemical species, in particular, of a s ...

(≈500

nanogram To help compare different ''Order of magnitude, orders of magnitude'', the following lists describe various ''mass'' levels between 10−67 kilogram, kg and 1052 kg. The least massive thing listed here is a graviton, and the most massive thi ...

s per

milliliter The litre (Commonwealth English, Commonwealth spelling) or liter (American English, American spelling) (SI symbols L and l, other symbol used: ℓ) is a metric units, metric unit of volume. It is equal to 1 cubic decimetre (dm3), 1000 cubic c ...

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 ...

). PFOSA was the most toxic perfluorinated compound in a study with

PC12 cells PC12 is a Cell culture#Common cell lines, cell line derived from a pheochromocytoma of the rat adrenal medulla, that have an Embryonic stem cell, embryonic origin from the neural crest that has a mixture of neuroblast, neuroblastic cells and eosin ...

. Concentrations ranged from 10 to 250 micromolar in the study (or 5000 to 125,000 parts per billion). Wildlife

biomonitoring In analytical chemistry, biomonitoring is the measurement of the body burden of toxic chemical compounds, elements, or their metabolites, in biological substances. Often, these measurements are done in blood and urine. Biomonitoring is performe ...

studies have found the highest level of PFOSA in 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 ...

common dolphin The common dolphin (''Delphinus delphis'') is the most abundant cetacean in the world, with a global population of about six million. Despite this fact and its vernacular name, the common dolphin is not thought of as the archetypal dolphin, wit ...

(

Mediterranean Sea The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern Eur ...

, Italy) with a concentration of 878

; the liver of

mink Mink are dark-colored, semiaquatic, carnivorous mammals of the genera ''Neogale'' and '' Mustela'' and part of the family Mustelidae, which also includes weasels, otters, and ferrets. There are two extant species referred to as "mink": the A ...

from

Illinois Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. It borders on Lake Michigan to its northeast, the Mississippi River to its west, and the Wabash River, Wabash and Ohio River, Ohio rivers to its ...

, US, contained 590 parts per billion.Supporting Information
(PDF). In fish, the highest levels detected were in the liver of Norway

Pike Pike, Pikes or The Pike may refer to: Fish * Blue pike or blue walleye, an extinct color morph of the yellow walleye ''Sander vitreus'' * Ctenoluciidae, the "pike characins", some species of which are commonly known as pikes * ''Esox'', genus of ...

(91 parts per billion) and

homogenate Homogeneity and heterogeneity are concepts relating to the uniformity of a substance, process or image. A homogeneous feature is uniform in composition or character (i.e., color, shape, size, weight, height, distribution, texture, language, i ...

s of

slimy sculpin The slimy sculpin (''Cottus cognatus'') is a freshwater species of fish belonging to the family Cottidae, which is the largest sculpin family. They usually inhabit cold rocky streams or lakes across North America, ranging from the Great Lakes, s ...

(150 parts per billion) from

Lake Ontario Lake Ontario is one of the five Great Lakes of North America. It is bounded on the north, west, and southwest by the Canadian province of Ontario, and on the south and east by the U.S. state of New York (state), New York. The Canada–United Sta ...

. Differences in biotransformation across species could explain some of its presence. In humans, PFOSA has been detected in sub- to low-parts per billion levels; for example, in 1999–2000 US serum samples, the 95th

percentile In statistics, a ''k''-th percentile, also known as percentile score or centile, is a score (e.g., a data point) a given percentage ''k'' of all scores in its frequency distribution exists ("exclusive" definition) or a score a given percentage ...

(or value where only 5% of the population was higher) was 1.4 parts per billion while in 2003–2004 the 95th percentile fell to 0.2 parts per billion.Supplemental Material
(PDF). However, whole-blood concentrations are about five times higher than those in blood plasma or serum.

References

{{reflist, 2

External links

Perfluorinated Alkylated Substances (PFAS) in the European Nordic Environment
Perfluorinated compounds Sulfonamides

See also

References

External links