{{Chembox | Name = Perfluorohexanoic acid | ImageFile = Perfluorohexanoic acid.svg | ImageFile2 = Perfluorohexanoic acid 3D BS.png | OtherNames = undecafluorohexanoic acid <br /> C<sub>6</sub> | IUPACName = 2,2,3,3,4,4,5,5,6,6,6-undecafluorohexanoic acid | Section1 = {{Chembox Identifiers | Abbreviations = PFHxA | CASNo = 307-24-4 | ChEMBL = 3183213 | ChemSpiderID = 60864 | PubChem = 67542 | EINECS = | EC_number = 206-196-6 | UNII = ZP34Q2220R | MeSHName = | ChEBI = 83492 | RTECS = | SMILES = C(=O)(C(C(C(C(C(F)(F)F)(F)F)(F)F)(F)F)(F)F)O | InChI = 1S/C6HF11O2/c7-2(8,1(18)19)3(9,10)4(11,12)5(13,14)6(15,16)17/h(H,18,19) | InChIKey = PXUULQAPEKKVAH-UHFFFAOYSA-N }} | Section2 = {{Chembox Properties | C = 6 | O = 2 | H = 1 | F = 11 | Appearance = Colorless liquid | Density = 1.757 g/cm<sup>3</sup><ref name="Sigma" /> | MeltingPt = | BoilingPt = 157 °C (314.6 °F; 430 K)<ref name="PubChem">{{Cite web |last=PubChem |title=Perfluorohexanoic acid |url=https://pubchem.ncbi.nlm.nih.gov/compound/67542 |access-date=2022-04-05 |website=pubchem.ncbi.nlm.nih.gov |language=en}}</ref> | LogP = 3.48 <ref name="PubChem" /> | VaporPressure = 1.98 mm Hg <ref name="PubChem" /> | HenryConstant = | AtmosphericOHRateConstant = 5.2 10<sup>−13</sup> cu cm/molec sec <ref name="PubChem" /> | pKa = −0.16 <ref name="PubChem" /> | Solubility = | SolubleOther = }} | Section7 = {{Chembox Hazards | MainHazards = | NFPA-H = | NFPA-F = | NFPA-I = | NFPA-S = | ExternalSDS = <ref name="Sigma">{{Cite web |date=August 3, 2021 |title=SAFETY DATA SHEET Perfluorohexanoic acid |url=https://www.sigmaaldrich.com/US/en/sds/sial/43809 |access-date=April 5, 2022 |website=Sigmaaldrich}}</ref> | GHSPictograms = {{GHS05}} | GHSSignalWord = Danger | HPhrases = {{H-phrases|314}} | PPhrases = {{P-phrases|264|280|301+330+331|303+361+353|304+340+310|305+351+338+310|363|405|501}} | LD50 = 140 mg/L (''B.'' ''calyciflorus'' over 24hrs) | PEL = }} |Section8={{Chembox Related | OtherCompounds = Trifluoroacetic acid<br>Perfluoropropanoic acid<br>Perfluorobutanoic acid<br>Perfluoropentanoic acid }} }}
'''Perfluorohexanoic acid''' ('''PFHxA''') is a perfluorocarboxylic acid derivative of hexanoic acid. Side-chain fluorinated polymers and fluorotelomer compounds with five carbon atoms or more commonly degrade into perfluorohexanoic acid.<ref>{{Cite book|title=Synthesis Report on Understanding Side-Chain Fluorinated Polymers and Their Life Cycle|url=https://www.oecd.org/en/publications/synthesis-report-on-understanding-side-chain-fluorinated-polymers-and-their-life-cycle_e13559f7-en.html|publisher=OECD|isbn=978-92-64-79065-0|series=OECD Series on Risk Management of Chemicals|doi=10.1787/e13559f7-en|language=en|last=OECD|year=2022}}</ref><ref name=":0">{{Cite journal |last1=Zahid |first1=Muhammad |last2=Heredia-Guerrero |first2=Jose A. |last3=Athanassiou |first3=Athanassia |last4=Bayer |first4=Ilker S. |date=July 2017 |title=Robust water repellent treatment for woven cotton fabrics with eco-friendly polymers |url=https://linkinghub.elsevier.com/retrieve/pii/S1385894717303431 |journal=Chemical Engineering Journal |language=en |volume=319 |pages=321–332 |doi=10.1016/j.cej.2017.03.006|bibcode=2017ChEnJ.319..321Z |hdl=10261/344622 |hdl-access=free|url-access=subscription }}</ref>
Perfluorohexanoic acid does not seem to persistently bioaccumulate in the manner of many other PFAS. For example, in a study sponsored by the Swedish EPA, Swedish ski wax technicians, who have high PFAS exposure, did not have significantly higher levels of PFHxA in their blood samples when compared to the general population median for their age groups, even while having concentrations of other PFAS, like PFOA, up to 44 times higher than the general population.<ref>{{cite journal |last1=Nilsson |first1=Helena |last2=Kärrman |first2=Anna |last3=Westberg |first3=Håkan |last4=Rotander |first4=Anna |last5=van Bavel |first5=Bert |last6=Lindström |first6=Gunilla |title=A Time Trend Study of Significantly Elevated Perfluorocarboxylate Levels in Humans after Using Fluorinated Ski Wax |journal=Environmental Science & Technology |date=15 March 2010 |volume=44 |issue=6 |pages=2150–2155 |doi=10.1021/es9034733|pmid=20158198 |bibcode=2010EnST...44.2150N }}</ref>
In 2020 Michigan adopted drinking water standards for five previously unregulated PFAS compounds including PFHxA which has a maximum contaminant level (MCL) of 400 parts per billion (ppb).<ref>{{Cite web |last=Matheny |first=Keith |date=3 August 2020 |title=Michigan's drinking water standards for these chemicals now among toughest in nation |url=https://www.freep.com/story/news/local/michigan/2020/08/03/tougher-pfas-standards-drinking-water-michigan/5574268002/ |url-status=live |archive-url=https://web.archive.org/web/20220131152306/https://eu.freep.com/story/news/local/michigan/2020/08/03/tougher-pfas-standards-drinking-water-michigan/5574268002/ |archive-date=31 January 2022 |access-date=31 March 2022 |website=Detroit Free Press}}</ref><ref>{{Cite web |date=3 August 2020 |title=New state drinking water standards pave way for expansion of Michigan's PFAS clean-up efforts |url=https://www.michigan.gov/egle/0,9429,7-135--535602--,00.html |url-status=live |archive-url=https://web.archive.org/web/20220103083526/https://www.michigan.gov/egle/0,9429,7-135--535602--,00.html |archive-date=3 January 2022 |access-date=5 April 2022 |website=Michigan.gov}}</ref>
Its placing on the market and use will be restricted in the EEA and Switzerland by 2026.<ref>[https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=OJ:L_202402462 Commission Regulation (EU) 2024/2462 of 19 September 2024 amending Annex XVII to Regulation (EC) No 1907/2006 of the European Parliament and of the Council as regards undecafluorohexanoic acid (PFHxA), its salts and PFHxA-related substances]</ref><ref>{{Cite web|title=ChemRRV, Anhang 1.16|url=https://www.fedlex.admin.ch/eli/cc/2005/478/de#annex_1_16|website=www.fedlex.admin.ch|access-date=2025-12-02}}</ref>
== References == <references />
Category:Perfluorocarboxylic acids