{{Chembox | Verifiedfields = changed | Watchedfields = changed | verifiedrevid = 411852757 | Name = Perfluorononanoic acid | ImageFile = Perfluorononanoic acid.svg | ImageClass = skin-invert-image | ImageSize = 220px | ImageFile2 = Perfluorononanoic acid 3D BS.png | ImageClass2 = bg-transparent | ImageSize2 = 220px | IUPACName = Heptadecafluorononanoic acid | OtherNames = perfluoro-''n''-nonanoic acid, PFNA, perfluorononanoate, C<sub>9</sub> PFCA |Section1={{Chembox Identifiers | CASNo_Ref = {{cascite|correct|??}} | CASNo = 375-95-1 | Beilstein = 1897287 | ChEBI_Ref = {{ebicite|correct|EBI}} | ChEBI = 38397 | ChEMBL = 426404 | ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} | ChemSpiderID = 61138 | EINECS = 206-801-3 | Gmelin = 317302 | PubChem = 67821 | RTECS = | UNII_Ref = {{fdacite|correct|FDA}} | UNII = 5830Z6S63M | SMILES = OC(=O)C(F)(F)C(F)(F)C(F)(F)C(F)(F)C(F)(F)C(F)(F)C(F)(F)C(F)(F)F | StdInChI_Ref = {{stdinchicite|changed|chemspider}} | StdInChI = 1S/C9HF17O2/c10-2(11,1(27)28)3(12,13)4(14,15)5(16,17)6(18,19)7(20,21)8(22,23)9(24,25)26/h(H,27,28) | StdInChIKey_Ref = {{stdinchicite|changed|chemspider}} | StdInChIKey = UZUFPBIDKMEQEQ-UHFFFAOYSA-N }} |Section2={{Chembox Properties | Formula = C<sub>9</sub>HF<sub>17</sub>O<sub>2</sub> | MolarMass = 464.08 g/mol | Appearance = white crystalline powder | Density = | Solubility = 9.5 g/L<ref>{{cite web |url=http://msds.chem.ox.ac.uk/PE/perfluorononanoic_acid.html |title=Safety (MSDS) data for perfluorononanoic acid |work=PTCL Safety web site |access-date=11 January 2009 |archive-date=1 April 2009 |archive-url=https://web.archive.org/web/20090401022230/http://msds.chem.ox.ac.uk/PE/perfluorononanoic_acid.html |url-status=dead }}</ref> <!--source provides no guarantee for accuracy--> | Solvent = other solvents | SolubleOther = polar organic solvents | MeltingPtC = 59 to 62 | MeltingPt_ref = <ref>{{cite web |url=http://www.sigmaaldrich.com/catalog/ProductDetail.do?N4=394459&#124;ALDRICH&N5=Product%20No.&#124;BRAND_KEY&F=SPEC |title=Perfluorononanoic acid 97% |work=Sigma-Aldrich |access-date=11 January 2009}}</ref> | BoilingPtC = 218 | BoilingPt_ref = <ref>{{cite web |url=http://www.chemicalbook.com/ChemicalProductProperty_EN.aspx?CBNumber=CB0211518 |title=Perfluorononanoic acid |work=ChemicalBook |access-date=11 January 2009 |archive-date=13 June 2018 |archive-url=https://web.archive.org/web/20180613040839/http://www.chemicalbook.com/ChemicalProductProperty_EN.aspx?CBNumber=CB0211518 |url-status=dead }}</ref> | pKa = ~0<ref name=Goss2008>{{cite journal | author =Goss KU | title =The pKa values of PFOA and other highly fluorinated carboxylic acids | journal =Environ. Sci. Technol. | volume =42 |issue=2 |pages=456–458 |date=July 2008 | pmid =18284146 |doi=10.1021/es702192c| bibcode =2008EnST...42..456G }}</ref><ref name=Rayne2010>{{cite journal |vauthors=Rayne S, Forest K | title =Theoretical studies on the pKa values of perfluoroalkyl carboxylic acids | journal =J. Mol. Struct. (Theochem) | volume =949 |issue=1–3 |pages=60–69 |date=June 2010 | doi =10.1016/j.theochem.2010.03.003}}</ref> | Viscosity = }} |Section7={{Chembox Hazards | ExternalSDS = | MainHazards = Strong acid and suspected carcinogen | GHSPictograms = {{GHS05}}{{GHS07}}{{GHS08}} | GHSSignalWord = Danger | HPhrases = {{H-phrases|302|318|332|351|360|362|372}} | PPhrases = {{P-phrases|201|202|260|261|263|264|270|271|280|281|301+312|304+312|304+340|305+351+338|308+313|310|312|314|330|405|501}} }} |Section8={{Chembox Related | OtherFunction_label = compounds | OtherFunction = Trifluoroacetic acid (TFA), Perfluorooctanoic acid (PFOA), Perfluorooctanesulfonic acid (PFOS) }} }} '''Perfluorononanoic acid''', or '''PFNA''', is a synthetic perfluorinated carboxylic acid that is also a persistent organic pollutant. As the name implies it is the perfluorinated analogue of nonanoic acid and is classified as a PFAS. It is used as a fluorosurfactant.

==Chemistry and properties== In acidic form it is a highly reactive strong acid. In its conjugate base form as a salt it is stable and commonly ion paired with ammonium. In the commercial product Surflon S-111 (CAS 72968-3-88) it is the primary compound present by weight. PFNA is used as surfactant for the production of the fluoropolymer polyvinylidene fluoride.<ref name=Prevedouros2006>{{cite journal |vauthors=Prevedouros K, Cousins IT, Buck RC, Korzeniowski SH | title =Sources, fate and transport of perfluorocarboxylates | journal =Environ Sci Technol | volume =40 |issue=1 |pages=32–44 |date=January 2006 | doi =10.1021/es0512475 |pmid=16433330| bibcode =2006EnST...40...32P}} [http://pubs.acs.org/doi/suppl/10.1021/es0512475/suppl_file/es0512475.pdf Supporting Information] (PDF)</ref><ref>{{cite conference | title =PERFORCE &mdash; PERFLUORINATED ORGANIC COMPOUNDS IN THE EUROPEAN ENVIRONMENT | others =Institute for Biodiversity and Ecosystem Dynamics, Universiteit van Amsterdam | date =2006-09-15 | url =http://www.science.uva.nl/perforce/Final%20reportA.pdf |pages=18 | access-date =2009-02-15}}</ref> It is produced mainly in Japan by the oxidation of a linear fluorotelomer olefin mixture containing F(CF<sub>2</sub>)<sub>8</sub>CH=CH<sub>2</sub>. It can also be synthesized by the carboxylation of F(CF<sub>2</sub>)<sub>8</sub>I. PFNA can form from the biodegradation of 8:2 fluorotelomer alcohol.<ref>{{cite journal |vauthors=Henderson WM, Smith MA | title =Perfluorooctanoic acid and perfluorononanoic acid in fetal and neonatal mice following in utero exposure to 8–2 fluorotelomer alcohol | journal =Toxicol. Sci. |volume=95 |issue=2 |pages=452–61 |date=February 2007 | pmid =17093205 |doi=10.1093/toxsci/kfl162 |doi-access=free }}</ref> Additionally, it is considered a probable degradation product of many other compounds.<ref>{{cite conference | title =Lists of PFOS, PFAS, PFOA, PFCA, related compounds and chemicals that may degrade to PFCA | conference =Environment Directorate-Joint Meeting of the Chemicals Committee and the Working Party on Chemicals, Pesticides, and Biotechnology | others =Organisation for Economic Co-operation and Development | date =2007-08-21 | url =http://www.olis.oecd.org/olis/2006doc.nsf/LinkTo/NT00000F9A/$FILE/JT03231059.PDF | access-date =2008-09-19}}</ref>

PFNA is the largest perfluorinated carboxylic acid surfactant. Fluorocarbon derivatives with terminal carboxylates are only surfactants when they possess five to nine carbons.<ref name=Salager2002>{{cite conference | first =Jean-Louis | last =Salager | title =FIRP Booklet # 300-A: Surfactants-Types and Uses | pages =44 | publisher =Universidad de los Andes Laboratory of Formulation, Interfaces Rheology, and Processes | date =2002 | url =http://nanoparticles.org/pdf/Salager-E300A.pdf | access-date =2008-09-07 | archive-date =2020-07-31 | archive-url =https://web.archive.org/web/20200731194249/http://nanoparticles.org/pdf/Salager-E300A.pdf | url-status =dead }}</ref> Fluorosurfactants reduce the surface tension of water down to half of what hydrocarbon surfactants can by concentrating at the liquid-air interface due to the lipophobicity of fluorocarbons.<ref name=Salager2002/><ref>{{cite web |url = http://www.masonsurfactants.com/Products/Fluorosurfactant.htm |title = Fluorosurfactant &mdash; Structure / Function |publisher = Mason Chemical Company |access-date = 11 January 2009 |url-status = dead |archive-url = https://web.archive.org/web/20080705074650/http://www.masonsurfactants.com/Products/Fluorosurfactant.htm |archive-date = 5 July 2008 }}</ref> PFNA is very stable and is not known to degrade in the environment by oxidative processes because of the strength of the carbon–fluorine bond and the electronegativity of fluorine.

==Environmental and health concerns== Like the eight-carbon PFOA, the nine-carbon PFNA is a developmental toxicant and an immune system toxicant.<ref name=Fang>{{cite journal |vauthors=Fang X, Zhang L, Feng Y, Zhao Y, Dai J | title=Immunotoxic effects of perfluorononanoic acid on BALB/c mice |journal =Toxicol. Sci. |volume=105 |issue=2 |pages=312–21 |date=October 2008 |pmid=18583369 |doi=10.1093/toxsci/kfn127 |doi-access=free }}</ref> However, longer chain perfluorinated carboxylic acids (PFCAs) are considered more bioaccumulative and toxic.<ref>{{cite journal | vauthors=Del Gobbo L, Tittlemier S, Diamond M, etal |title=Cooking decreases observed perfluorinated compound concentrations in fish |journal=Journal of Agricultural and Food Chemistry |volume=56 |issue=16 |pages=7551–9 |date=August 2008 |pmid=18620413 |doi=10.1021/jf800827r}}</ref> PFNA is an agonist of the nuclear receptors PPARα and PPARγ.<ref name=Fang/> In the years between 1999–2000 and 2003–2004, the geometric mean of PFNA increased from 0.5 parts per billion to 1.0 parts per billion in the US population's blood serum.<ref name="Calafat2007">{{cite journal |vauthors=Calafat AM, Wong LY, Kuklenyik Z, Reidy JA, Needham LL |title=Polyfluoroalkyl chemicals in the U.S. population: data from the National Health and Nutrition Examination Survey (NHANES) 2003–2004 and comparisons with NHANES 1999–2000 |journal=Environ. Health Perspect. |volume=115 |issue=11 |pages=1596–602 |date=November 2007 |pmid=18007991 |pmc=2072821 |doi=10.1289/ehp.10598 |url=http://www.ehponline.org/members/2007/10598/10598.html |access-date=2009-01-11 |archive-url=https://web.archive.org/web/20090120064652/http://www.ehponline.org/members/2007/10598/10598.html |archive-date=2009-01-20 |url-status=dead }}</ref> and has also been found in human follicular fluid <ref>{{Cite journal |last=Bach |first=Cathrine Carlsen |last2=Bech |first2=Bodil Hammer |last3=Nohr |first3=Ellen Aagaard |last4=Olsen |first4=Jørn |last5=Matthiesen |first5=Niels Bjerregård |last6=Bossi |first6=Rossana |last7=Uldbjerg |first7=Niels |last8=Bonefeld-Jørgensen |first8=Eva Cecilie |last9=Henriksen |first9=Tine Brink |date=2015-10-01 |title=Serum perfluoroalkyl acids and time to pregnancy in nulliparous women |journal=Environmental Research |volume=142 |pages=535–541 |doi=10.1016/j.envres.2015.08.007|pmid=26282225 |bibcode=2015ER....142..535B }}</ref> In a cross-sectional study of 2003–2004 US samples, a higher (13.9 milligram per deciliter) total cholesterol level was observed in when the highest quartile was compared to the lowest.<ref name=lipid>{{cite journal|author= Nelson JW, Hatch EE, Webster, TF|title= Exposure to Polyfluoroalkyl Chemicals and Cholesterol, Body Weight, and Insulin Resistance in the General U.S. Population|journal= Environ. Health Perspect.|volume= 118|issue= 2|pages= 197–202|year= 2009|pmid= 20123614|pmc= 2831917|doi= 10.1289/ehp.0901165}}</ref> Non-HDL cholesterol (or "bad cholesterol") levels were also higher in samples with more PFNA.

In bottlenose dolphins from Delaware Bay, PFNA was the perfluorinated carboxylic acid measured in the highest concentration in blood plasma; it was found in concentrations well over 100 parts per billion.<ref>{{cite journal | vauthors=Houde M, Wells RS, Fair PA, etal | title =Polyfluoroalkyl compounds in free-ranging bottlenose dolphins (Tursiops truncatus) from the Gulf of Mexico and the Atlantic Ocean | journal =Environ. Sci. Technol. |volume=39 |issue=17 |pages=6591–8 |date=September 2005 | pmid =16190216 |doi=10.1021/es0506556| bibcode =2005EnST...39.6591H }}</ref> PFNA has been detected in polar bears in concentrations over 400 parts per billion.<ref>{{cite conference |first=Derek |last=Muir |title=Biomonitoring of perfluoroalkyl acids: An overview of the global and temporal trend data |conference=Fluoros |others=Environment Canada - National Water Research Institute |url =http://www.chem.utoronto.ca/symposium/fluoros/pdfs/Fluoros-PFAbiomonitoring(Muir).pdf |access-date =2009-01-11}}</ref> PFNA was the perfluorinated chemical measured in the highest concentration in Russian Baikal seals.<ref>{{cite news |title =Water Pollution Continues At Famous Russian Lake |url=https://www.sciencedaily.com/releases/2008/03/080324103026.htm |work=ScienceDaily |date=25 March 2008 |access-date=11 January 2009}}</ref> However, PFOS is the perfluorinated compound that dominates in most wildlife biomonitoring samples.<ref name=hou>{{cite journal |vauthors=Houde M, Martin JW, Letcher RJ, Solomon KR, Muir DC |title=Biological monitoring of polyfluoroalkyl substances: A review | journal =Environ. Sci. Technol. |volume=40 |issue=11 |pages=3463–73 |date=June 2006 | pmid =16786681 |doi=10.1021/es052580b|bibcode=2006EnST...40.3463H }} [http://pubs.acs.org/doi/suppl/10.1021/es052580b/suppl_file/es052580bsi20060303_021408.pdf Supporting Information] (PDF).</ref>

===Drinking water regulations=== In the United States, PFNA is currently regulated only at the state level.

New Jersey became the first American state to set a standard for PFNA in September 2018, with a maximum contaminant level (MCL) of 13 ppt.<ref>{{cite news |last=Fallon |first=Scott |title=New Jersey becomes first state to regulate dangerous chemical PFNA in drinking water |url=https://www.northjersey.com/story/news/environment/2018/09/06/new-jersey-first-state-regulate-dangerous-chemical-pfna-pfoa/1210328002/ |date=2018-09-06 |work=North Jersey Record |location=Woodland Park, NJ}}</ref><ref>{{cite web |title=Maximum Contaminant Levels (MCLs) for Perfluorononanoic Acid and 1,2,3-Trichloropropane; Private Well Testing for Arsenic, Gross Alpha Particle Activity, and Certain Synthetic Organic Compounds |url=https://advance.lexis.com/api/document/collection/administrative-codes/id/5T61-TR60-01XC-F17T-00008-00?cite=50%20N.J.R.%201939(a)&context=1000516 |date=2018-09-04 |publisher=NJDEP |id=50 N.J.R. 1939(a)}}</ref> This was soon followed by similar regulations for PFOA and PFOS.<ref>{{cite web |title=Adoption of ground water quality standards and maximum contaminant levels for perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) |url=https://www.state.nj.us/dep/srp/srra/listserv_archives/2020/20200601_srra.html |date=2020-06-01 |publisher=New Jersey Department of Environmental Protection (NJDEP) |location=Trenton, NJ}}</ref>

Other states such as Massachusetts,<ref>{{cite web |title=Massachusetts PFAS Standard for Public Drinking Water Supplies |url=https://www.mass.gov/info-details/per-and-polyfluoroalkyl-substances-pfas-in-drinking-water#drinking-water-standards-and-health-information |publisher=Massachusetts DEP |access-date=25 November 2025}}</ref> Rhode Island,<ref>{{cite web |title=R.I. Gen. Laws § 46-32-2 |url=https://webserver.rilegislature.gov//Statutes/TITLE46/46-32/46-32-2.htm |access-date=25 November 2025}}</ref> and Vermont<ref>{{cite web |title=PFAS Roadmap |url=https://dec.vermont.gov/sites/dec/files/documents/DEC-PFAS-Roadmap-December-2023-Final.pdf |publisher=Vermont Department of Environmental Conservation |access-date=25 November 2025 |date=December 2023}}</ref> have MCLs for the sum of several PFAS that all include PFNA.

In August 2020 the State of Michigan adopted drinking water standards for 5 previously unregulated PFAS compounds and lowered acceptable levels for 2 previously regulated compounds PFOS and PFOA to 16 ppt and 8 ppt respectively. PFNA has a MCL of 6 ppt.<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>

On April 10, 2024, the U.S. Environmental Protection Agency (EPA) announced the final National Primary Drinking Water Regulation (NPDWR) establishing Maximum Contaminant Levels (MCLs) for six PFAS including PFNA. However, in May, 2025, EPA announced changes that would rescind the regulations for PFNA, PFHxS, HFPO-DA (commonly known as GenX), and PFBS.<ref>{{cite web |title=EPA Announces It Will Keep Maximum Contaminant Levels for PFOA, PFOS |url=https://www.epa.gov/newsreleases/epa-announces-it-will-keep-maximum-contaminant-levels-pfoa-pfos |publisher=U.S. E.P.A. |access-date=25 November 2025 |date=May 14, 2025}}</ref>

The European Union regulates PFNA among a sum of many PFAS.<ref>{{cite web |title=Directive (EU) 2020/2184 of the European Parliament and of the Council of 16 December 2020 on the quality of water intended for human consumption (recast) |url=https://eur-lex.europa.eu/eli/dir/2020/2184/oj/eng |publisher=Publications Office of the European Union |access-date=25 November 2025}}</ref>

===Food Regulation=== In 2020, the European Food Safety Authority added PFNA in its revised safety threshold for PFAS that accumulate in the body. They set the threshold for a group of four PFAS of a tolerable weekly intake of 4.4 nanograms per kilogram of body weight per week.<ref>{{cite web |title=PFAS in food: EFSA assesses risks and sets tolerable intake |url=https://www.efsa.europa.eu/en/news/pfas-food-efsa-assesses-risks-and-sets-tolerable-intake |publisher=The European Food Safety Authority |access-date=17 October 2020 |date=September 17, 2020}}</ref>

===Product Restrictions=== In 2020, a California bill was passed banning PFNA as an intentionally added ingredient from cosmetics.<ref>{{cite web |title=Assembly Bill No. 2762 |url=https://leginfo.legislature.ca.gov/faces/billTextClient.xhtml?bill_id=201920200AB2762 |publisher=State of California |access-date=10 October 2020 |date=September 30, 2020}}</ref>

==See also== *Organofluorine compounds

==References== {{reflist}}

==External links== *[https://web.archive.org/web/20090711055130/http://www.epa.gov/nrmrl/pubs/600r09033/600r09033.html Perfluorocarboxylic Acid Content in 116 Articles of Commerce] [https://web.archive.org/web/20090710005512/http://www.epa.gov/nrmrl/pubs/600r09033/600r09033.pdf PDF] *[https://web.archive.org/web/20090509204147/http://www.cdc.gov/exposurereport/pdf/factsheet_pfc.pdf Centers for Disease Control and Prevention, Polyfluorochemicals fact sheet] *[https://web.archive.org/web/20071020035203/http://www.kemi.se/upload/Trycksaker/Pdf/Rapporter/Report7_06.pdf Perfluorinated substances and their uses in Sweden] *[http://www.rikz.nl/thema/ikc/rapport2002/rikz2002043.pdf Perfluoroalkylated substances, Aquatic environmental assessment] *[http://assets.panda.org/downloads/fact_sheet___pfcs_food.pdf Chain of Contamination: The Food Link, Perfluorinated Chemicals (PFCs) Incl. PFOS & PFOA]

{{PPAR modulators}}

Category:Perfluorocarboxylic acids Category:Persistent organic pollutants under the Stockholm Convention Category:PBT substances Category:Anionic surfactants