Fluorotelomer alcohols, or FTOHs, are fluorotelomer

Fluorotelomer

Fluorotelomers are fluorocarbon-based oligomers, or telomers, synthesized by telomerization. Some fluorotelomers and fluorotelomer-based compounds are a source of environmentally persistent perfluorinated carboxylic acids such as PFOA and PFNA, while others are under extended...

s with an alcohol

Alcohol

In chemistry, an alcohol is an organic compound in which the hydroxy functional group is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms....

 functional group

Functional group

In organic chemistry, functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules. The same functional group will undergo the same or similar chemical reaction regardless of the size of the molecule it is a part of...

. They are volatile

Volatility (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...

 precursors to perfluorinated carboxylic acid

Perfluorinated carboxylic acid

Perfluorinated carboxylic acids , or perfluorocarboxylates are fully fluorinated organofluorine compounds—or perfluorinated compounds—with carboxylic acid or carboxylate functional groups. PFCAs are fluorocarbon derivatives...

s, such as PFOA and PFNA, and other compound

Chemical compound

A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...

s.

Naming

Commonly, an individual fluorotelomer alcohol molecule

Molecule

A molecule is an electrically neutral group of at least two atoms held together by covalent chemical bonds. Molecules are distinguished from ions by their electrical charge...

 is named by the number of carbons that are fluorinated versus the number that are 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....

-based. For example, 8:2 fluorotelomer alcohol would represent a molecule with 8 fluorinated carbons and a 2 carbon ethyl alcohol group. The structure of a fluorotelomer alcohol is most commonly F(CF₂)_nCH₂CH₂OH, where n is an even number.

Chemistry and economic concerns

The synthesis of fluorotelomer alcohols requires a varying number of tetrafluoroethylene

Tetrafluoroethylene

Tetrafluoroethylene is a chemical compound with the formula C2F4. It is the simplest alkene fluorocarbon. This gaseous species is used primarily in the industrial preparation of polymers.-Properties:...

 monomers that form an oligomer

Oligomer

In chemistry, an oligomer is a molecule that consists of a few monomer units , in contrast to a polymer that, at least in principle, consists of an unlimited number of monomers. Dimers, trimers, and tetramers are oligomers. Many oils are oligomeric, such as liquid paraffin...

 with a pentafluoroethyl iodide telogen. The fluorinated iodide then undergoes an addition with ethylene

Ethylene

Ethylene is a gaseous organic compound with the formula . It is the simplest alkene . Because it contains a carbon-carbon double bond, ethylene is classified as an unsaturated hydrocarbon. Ethylene is widely used in industry and is also a plant hormone...

 to form a organoiodine compound

Organoiodine compound

Organoiodine compounds are organic compounds that contain one or more carbon–iodine bonds. They occur widely in organic chemistry, but are relatively rare in nature...

 with increased synthesis possibilities. The terminal iodine

Iodine

Iodine is a chemical element with the symbol I and atomic number 53. The name is pronounced , , or . The name is from the , meaning violet or purple, due to the color of elemental iodine vapor....

 is replaced by a hydroxyl

Hydroxyl

A hydroxyl is a chemical group containing an oxygen atom covalently bonded with a hydrogen atom. In inorganic chemistry, the hydroxyl group is known as the hydroxide ion, and scientists and reference works generally use these different terms though they refer to the same chemical structure in...

 group to yield the fluorotelomer alcohol. Then the fluorotelomer alcohol can then be used to produce acrylate

Acrylate

The acrylate ion is the ion of acrylic acid.Acrylates are the salts and esters of acrylic acid. They are also known as propenoates ....

 polymer

Polymer

A polymer is a large molecule composed of repeating structural units. These subunits are typically connected by covalent chemical bonds...

s with 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....

 "backbones" with the fluorotelomer alcohols attached via ester

Ester

Esters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH group is replaced by an -O-alkyl group, and most commonly from carboxylic acids and...

 functional group

Functional group

In organic chemistry, functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules. The same functional group will undergo the same or similar chemical reaction regardless of the size of the molecule it is a part of...

s. However, because ester groups are vulnerable to hydrolysis

Hydrolysis

Hydrolysis is a chemical reaction during which molecules of water are split into hydrogen cations and hydroxide anions in the process of a chemical mechanism. It is the type of reaction that is used to break down certain polymers, especially those made by condensation polymerization...

 and microbial enzymes, these polymers are under investigation for their potential to degrade into environmental contaminants, threatening "the future of some carpet and fabric stain repellants and paper coatings made from these polymers." FTOHs can also be used as intermediates in the production of surfactants

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...

.

Environmental and health concerns

Fluorotelomer alcohols are volatile and widely detected in air. Fluorotelomer alcohols can biodegrade

Biodegradation

Biodegradation or biotic degradation or biotic decomposition is the chemical dissolution of materials by bacteria or other biological means...

 to perfluorinated carboxylic acids that persist in the environment and are found in the blood serum of populations and wildlife, such as the toxic PFOA and PFNA. The fluorotelomer alcohols 6:2 FTOH and 8:2 FTOH have been found to be estrogenic.
The atmospheric oxidation of fluorotelomer alcohols can also result in anthropogenic perfluorinated carboxylic acids. In addition to perfluorinated carboxylic acids, fluorotelomer alcohols can degrade to form unsaturated

Unsaturated compound

In organic chemistry, a saturated compound is a chemical compound that has of a chain of carbon atoms linked together by single bonds and has hydrogen atoms filling all of the other bonding orbitals of the carbon atoms. Alkanes are an example of saturated compounds...

 carboxylic acids which have been detected in 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...

s.
Fluorotelomer alcohols such as 4:2 FTOH, 6:2 FTOH, 8:2 FTOH, and 10:2 FTOH, have been identified as residuals in consumer products such as stain repellents, Zonyl FSE, and windshield wash, among others. The United States Environmental Protection Agency

United States Environmental Protection Agency

The U.S. Environmental Protection Agency is an agency of the federal government of the United States charged with protecting human health and the environment, by writing and enforcing regulations based on laws passed by Congress...

has asked eight chemical companies to reduce the amount of residuals, including fluorotelomer alcohols, from products.