Perfluorohexanoic acid

Perfluorohexanoic acid

Names
IUPAC name 2,2,3,3,4,4,5,5,6,6,6-undecafluorohexanoic acid
Other names methyl undecafluorohexanoate
Identifiers
CAS Number	307-24-4
3D model (JSmol)	Interactive image
Abbreviations	PFHxA
ChEBI	CHEBI:83492
ECHA InfoCard	100.005.634
EC Number	206-196-6
PubChem CID	67542
UNII	ZP34Q2220R
CompTox Dashboard (EPA)	DTXSID3031862
InChI 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) Key: PXUULQAPEKKVAH-UHFFFAOYSA-N
SMILES C(=O)(C(C(C(C(C(F)(F)F)(F)F)(F)F)(F)F)(F)F)O
Properties
Chemical formula	C6HF11O2
Molar mass	314.054 g·mol^−1
Appearance	Colorless liquid
Density	1.757 g/cm^3[1]
Boiling point	157 °C (314.6 °C; 430 K)[2]
log P	3.48 [2]
Vapor pressure	1.98 mm Hg [2]
Atmospheric OH rate constant	5.2 10^−13 cu cm/molec sec [2]
Acidity (pKa)	-0.16 [2]
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H314
Precautionary statements	P264, P280, P301+P330+P331, P303+P361+P353, P304+P340+P310, P305+P351+P338+P310, P363, P405, P501
Lethal dose or concentration (LD, LC):
LD50 (median dose)	140 mg/L (B. calyciflorus over 24hrs)
Safety data sheet (SDS)	[1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Perfluorohexanoic acid (PFHxA) is a fluorinated carboxylic acid derivative of hexanoic acid. Fluorinated polymers with six carbon or less commonly degrade into perfluorohexanoic acid.[3]

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.[4]

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).[5][6]

Its placing on the market and use will be restricted in the EEA by 2026.[7]

References

1. "SAFETY DATA SHEET Perfluorohexanoic acid". Sigmaaldrich. August 3, 2021. Retrieved April 5, 2022.
2. PubChem. "Perfluorohexanoic acid". pubchem.ncbi.nlm.nih.gov. Retrieved 2022-04-05.
3. Zahid, Muhammad; Heredia-Guerrero, Jose A.; Athanassiou, Athanassia; Bayer, Ilker S. (July 2017). "Robust water repellent treatment for woven cotton fabrics with eco-friendly polymers". Chemical Engineering Journal. 319: 321–332. doi:10.1016/j.cej.2017.03.006. hdl:10261/344622.
4. Nilsson, Helena; Kärrman, Anna; Westberg, Håkan; Rotander, Anna; van Bavel, Bert; Lindström, Gunilla (15 March 2010). "A Time Trend Study of Significantly Elevated Perfluorocarboxylate Levels in Humans after Using Fluorinated Ski Wax". Environmental Science & Technology. 44 (6): 2150–2155. doi:10.1021/es9034733.
5. Matheny, Keith (3 August 2020). "Michigan's drinking water standards for these chemicals now among toughest in nation". Detroit Free Press. Archived from the original on 31 January 2022. Retrieved 31 March 2022.
6. "New state drinking water standards pave way for expansion of Michigan's PFAS clean-up efforts". Michigan.gov. 3 August 2020. Archived from the original on 3 January 2022. Retrieved 5 April 2022.
7. 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