Fluorotelomer alcohol

Fluorotelomer alcohols, or FTOHs, are fluorotelomers with an alcohol functional group. They are volatile precursors to perfluorinated carboxylic acids, such as PFOA and PFNA, and other compounds.

8:2 fluorotelomer alcohol (8:2 FTOH)

Naming

Commonly, an individual fluorotelomer alcohol molecule is named by the number of carbons that are fluorinated versus the number that are hydrocarbon-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

The synthesis of fluorotelomer alcohols requires a varying number of tetrafluoroethylene monomers that form an oligomer with a pentafluoroethyl iodide telogen. The fluorinated iodide then undergoes an addition with ethylene to form an organoiodine compound with increased synthesis possibilities.[1] The terminal iodine is replaced by a hydroxyl group to yield the fluorotelomer alcohol. The fluorotelomer alcohol can then be used to produce acrylate polymers with the fluorotelomer alcohols attached via ester functional groups.[2]

Environmental and health concerns

Fluorotelomer alcohols are volatile and widely detected in air.[3][4]

Acrylate polymers with fluorotelomer substituents are under investigation for their potential to degrade into environmental contaminants."[2] FTOHs can also be used as intermediates in the production of surfactants.[5]

Fluorotelomer alcohols can biodegrade to perfluorinated carboxylic acids, whichpersist in the environment and are found in the blood serum of populations and wildlife, such as the toxic PFOA and PFNA.[6][7] The fluorotelomer alcohols 6:2 FTOH and 8:2 FTOH have been found to be estrogenic.[8]

10:2 fluorotelomer alcohol (10:2 FTOH)

The atmospheric oxidation of fluorotelomer alcohols can also result in anthropogenic perfluorinated carboxylic acids.[9] In addition to perfluorinated carboxylic acids, fluorotelomer alcohols can degrade to form unsaturated carboxylic acids which have been detected in bottlenose dolphins.[10] 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.[11] The United States Environmental Protection Agency has asked eight chemical companies to reduce the amount of residuals, including fluorotelomer alcohols, from products.[11]

References
  1. Lehmler HJ (March 2005). "Synthesis of environmentally relevant fluorinated surfactants—a review". Chemosphere. 58 (11): 1471–96. Bibcode:2005Chmsp..58.1471L. doi:10.1016/j.chemosphere.2004.11.078. PMID 15694468.
  2. Renner, Rebecca (February 2008). "Do perfluoropolymers biodegrade into PFOA?". Environ. Sci. Technol. 42 (3): 648–50. Bibcode:2008EnST...42..648R. doi:10.1021/es087093l. PMID 18323078.
  3. Oono S, Harada KH, Mahmoud MA, Inoue K, Koizumi A (October 2008). "Current levels of airborne polyfluorinated telomers in Japan". Chemosphere. 73 (6): 932–7. Bibcode:2008Chmsp..73..932O. doi:10.1016/j.chemosphere.2008.06.069. PMID 18701130.
  4. Piekarz AM, Primbs T, Field JA, Barofsky DF, Simonich S (December 2007). "Semivolatile fluorinated organic compounds in Asian and western U.S. air masses". Environ. Sci. Technol. 41 (24): 8248–55. Bibcode:2007EnST...41.8248P. doi:10.1021/es0713678. PMID 18200847.
  5. Martin JW, Chan K, Mabury SA, O'Brien PJ (February 2009). "Bioactivation of fluorotelomer alcohols in isolated rat hepatocytes". Chem. Biol. Interact. 177 (3): 196–203. doi:10.1016/j.cbi.2008.11.001. PMID 19041856.
  6. Henderson WM, Smith MA (February 2007). "Perfluorooctanoic acid and perfluorononanoic acid in fetal and neonatal mice following in utero exposure to 8-2 fluorotelomer alcohol". Toxicol. Sci. 95 (2): 452–61. doi:10.1093/toxsci/kfl162. PMID 17093205.
  7. Fang X, Zhang L, Feng Y, Zhao Y, Dai J (October 2008). "Immunotoxic effects of perfluorononanoic acid on BALB/c mice". Toxicol. Sci. 105 (2): 312–21. doi:10.1093/toxsci/kfn127. PMID 18583369.
  8. Maras M, Vanparys C, Muylle F, et al. (January 2006). "Estrogen-like properties of fluorotelomer alcohols as revealed by mcf-7 breast cancer cell proliferation". Environ. Health Perspect. 114 (1): 100–5. doi:10.1289/ehp.8149. PMC 1332663. PMID 16393665. Archived from the original on 2012-07-12.
  9. Sulbaek Andersen MP, Nielsen OJ, Hurley MD, et al. (March 2005). "Atmospheric chemistry of 4:2 fluorotelomer alcohol (n-C4F9CH2CH2OH): products and mechanism of Cl atom initiated oxidation in the presence of NOx". J Phys Chem A. 109 (9): 1849–56. Bibcode:2005JPCA..109.1849S. doi:10.1021/jp045672g. PMID 16833516.
  10. Houde M, Wells RS, Fair PA, et al. (September 2005). "Polyfluoroalkyl compounds in free-ranging bottlenose dolphins (Tursiops truncatus) from the Gulf of Mexico and the Atlantic Ocean". Environ. Sci. Technol. 39 (17): 6591–8. Bibcode:2005EnST...39.6591H. doi:10.1021/es0506556. PMID 16190216.
  11. Renner R; Eichenseher, Tasha; Thrall, Lizz (March 2006). "Leftovers may explain perfluorinated compound puzzle". Environ. Sci. Technol. 40 (5): 1376–7. Bibcode:2006EnST...40.1376R. doi:10.1021/es0626436. PMID 16568742.
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