GenX

GenX is a Chemours trademark name for a synthetic, short-chain organofluorine chemical compound, the ammonium salt of hexafluoropropylene oxide dimer acid (HFPO-DA) fluoride. It can also be used more informally to refer to the group of related fluorochemicals that are used to produce GenX.[1] DuPont began the commercial development of GenX in 2009 as a replacement for perfluorooctanoic acid (PFOA, also known as C8).[2]

For other uses, see Gen X (disambiguation).

Uses

The chemicals are used in products such as food packaging, paints, cleaning products, non-stick coatings, outdoor fabrics and firefighting foam.[3] The chemicals are manufactured by Chemours, a corporate spin-off of DuPont, in Fayetteville, North Carolina.[4]

GenX chemicals are used as replacements for PFOA for manufacturing fluoropolymers such as Teflon,[5][6] since PFOA and related compounds have been found to be toxic and carcinogenic.[7] However, in lab tests on rats, GenX has been shown to cause many of the same health problems as PFOA.[8][9]

Chemistry

The manufacturing process combines two molecules of hexafluoropropylene oxide (HFPO) to form HFPO-DA fluoride. HFDO-DA is converted into the ammonium salt that is the official GenX compound.[2]

The chemical process uses 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)propanoic acid (FRD-903) to generate ammonium 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)propanoate (FRD-902) and heptafluoropropyl 1,2,2,2-tetrafluoroethyl ether (E1).[10]

When GenX contacts water, it releases the ammonium group to become HFPO-DA. Because HFPO-DA is a strong acid, it deprotonates into its conjugate base, which can then be detected in the water.[2]

Pollution

The Chemours Fayetteville plant has released GenX compounds into the Cape Fear River, which is a drinking water source for the Wilmington, North Carolina area. The water supply may have been contaminated for a decade or more, resulting in controversy over its potential health effects.[11]

On September 5, 2017, the North Carolina Department of Environmental Quality (NCDEQ) ordered Chemours to halt discharges of all fluorinated compounds into the Cape Fear River. NCDEQ cited Chemours on November 14, 2017 for violating provisions in its NPDES wastewater discharge permit, following a chemical spill on October 6.[12]

On November 2, 2017, a federal lawsuit was filed by the Brunswick County Government alleging that DuPont failed to disclose research regarding potential risks from the chemical.[13]

On May 7, 2018, Cape Fear River Watch, a non-profit organization, announced its intention to bring suit against Chemours in 60 days for numerous Clean Water Act violations. Acting as legal counsel, Southern Environmental Law Center filed the suit under section 505(b) of the act.[14]

NCDEQ filed a draft consent order on its GenX investigation on November 21, 2018. The order would require Chemours to reduce air pollution emissions and water pollution discharges of GenX and other chemicals, and would levy civil penalties on the company of $13 million.[15] In February 2019 a North Carolina Superior Court judge ordered Chemours to monitor GenX air emissions, analyze PFAS in river sediment and provide drinking water filtration systems.[16]

In the first half of 2018 traces of GenX were found in the waters of the control wells in Trissino, where the Miteni company is based. The factory in question does not produce GenX but recovers it from the polymerization and washing waters from the Netherlands. The Arpav and the Province of Vicenza have requested the initiation of the procedure for the suspension of all Miteni plants.[17]

This episode is recounted in the 2018 documentary film The Devil We Know , the film Dark Waters and the book by Robert Bilott: Exposure: Poisoned Water, Corporate Greed, and One Lawyer's Twenty-Year Battle Against DuPont.

See also

References
  1. "C3 Dimer Acid and PFAS". Chemours. Retrieved 23 January 2020.
  2. Hogue, Cheryl (2018-02-12). "What's GenX still doing in the water downstream of a Chemours plant?". American Chemical Society (ACS). Retrieved 2019-08-21.
  3. "Basic Information on PFAS". PFOA, PFOS and Other PFASs. Washington, D.C.: U.S. Environmental Protection Agency (EPA). 2018-02-18.
  4. "GenX Frequently Asked Questions" (PDF). GenX Investigation. Raleigh, NC: North Carolina Department of Environmental Quality (NCDEQ). 2018-02-15.
  5. Beekman, M.; et al. (2016-12-12). "Evaluation of substances used in the GenX technology by Chemours, Dordrecht". National Institute for Public Health and the Environment (RIVM, The Netherlands). Retrieved 2017-07-23.
  6. "What is the difference between PFOA, PFOS and GenX and other replacement PFAS?". PFOA, PFOS and Other PFASs. EPA. 2018-02-18.
  7. Lau C., Anitole K., Hodes C., Lai D., Pfahles-Hutchens A., Seed J. (October 2007). "Perfluoroalkyl acids: a review of monitoring and toxicological findings" (PDF). Toxicol. Sci. 99 (2): 366–94. doi:10.1093/toxsci/kfm128. PMID 17519394.CS1 maint: uses authors parameter (link)
  8. Caverly Rae, JM; Craig, Lisa; Stone, Theodore W.; Frame, Steven R.; Buxton, L. William; Kennedy, Gerald L. (2015). "Evaluation of chronic toxicity and carcinogenicity of ammonium 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)-propanoate in Sprague–Dawley rats". Toxicology Reports. 2: 939–949. doi:10.1016/j.toxrep.2015.06.001. PMC 5598527. PMID 28962433.
  9. Lerner, Sharon (2016-03-03). "New Teflon Toxin Causes Cancer in Lab Animals". The Intercept. Retrieved 2018-12-14.
  10. "DuPont GenX Processing Aid for Making Fluoropolymer Resins" (PDF). 2016-02-09. Retrieved 2019-08-21.
  11. "N.C. drinking water tainted with chemical byproduct for decades?". CBS News. 2017-06-26.
  12. "GenX Timeline". NCDEQ. Retrieved 2018-04-22.
  13. Clabby, Catherine (2017-11-02). "Newest GenX Lawsuit Attacks DuPont Science". Chapel Hill, NC: North Carolina Health News.
  14. Alder, Cole (2018-05-16). "Cape Fear River Watch to file suit against Chemours". Per- and Polyfluoroalkyl Substances; News. Boston, MA: Northeastern University, Social Science Environmental Health Research Institute.
  15. "Consert Order (draft): North Carolina Department of Environmental Quality v. The Chemours Company" (PDF). NCDEQ. 2018-11-21. Bladen County, North Carolina Superior Court.
  16. "Court approves order to stop PFAS from entering Cape Fear River". Wilmington, NC: WECT News. 2019-02-26.
  17. https://cen.acs.org/environment/persistent-pollutants/Imports-used-PFAS-US-scrutinized/97/i9
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.