GenX chemicals are used as replacements for PFOA for manufacturing fluoropolymers such as Teflon,[2][6] the GenX chemicals serve as surfactants and processing aids in the fluoropolymer production process to lower the surface tension allowing the polymer particles to grow larger. The GenX chemicals are then removed from the final polymer by chemical treatment and heating.[7] PFOA and related compounds have been found to be toxic and carcinogenic.[8] However, in lab tests on rats, GenX has been shown to cause many of the same health problems as PFOA.[9][10]
The manufacturing process combines two molecules of hexafluoropropylene oxide (HFPO) to form HFPO-DA. HFDO-DA is converted into its ammonium salt that is the official GenX compound.[3][2]
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.[3]
HFPO-DA was first reported to be in the Cape Fear River in 2012[13] and an additional eleven polyfluoroalkyl substances (PFAS) were reported 2014.[14] These results were published as a formal paper in 2015.[15] The following year, North Carolina State University and the EPA jointly published a study demonstrating HFPO-DA and other PFAS were present in the Wilmington-area drinking water sourced from the Cape Fear river.[16]
In September 2017, the North Carolina Department of Environmental Quality (NCDEQ) ordered Chemours to halt discharges of all fluorinated compounds into the river. Following a chemical spill one month later, NCDEQ cited Chemours for violating provisions in its National Pollutant Discharge Elimination System wastewater discharge permit.[17] In November 2017, the Brunswick County Government filed a federal lawsuit alleging that DuPont failed to disclose research regarding potential risks from the chemical.[18]
In spring 2018, Cape Fear River Watch[19] sued Chemours for Clean Water Act violations and sued the NC Dpt of Environmental Quality for inaction.[20] After Cape Fear River Watch's suits were filed, NCDEQ filed a suit against Chemours, the result of all 3 lawsuits culmindated in a consent order.[21] The order signed by all 3 parties requires Chemours drastically reduce PFAS containing water discharges and air emissions, as well as sampling and filtration for well owners with contaminated wells, among other requirements. All materials relative to status of consent order requirements must be published to a public website,https://www.chemours.com/en/about-chemours/global-reach/fayetteville-works/compliance-testing. One requirement under the order was for non-targeted analysis which found 257 "unknown" PFAS being released from Fayetteville Works, (aside from the 100 'known' PFAS which can be quantified.[22] Cape Fear River Watch published[23] that their research of the NC DEQ permit file [24] indicates that the first PFAS byproducts were likely released from Fayetteville Works in 1976 with the production of Nafion which uses HFPO in production (otherwise known as GenX) and creates byproducts termed Nafion Byproducts 1 through 5, some of which have been found in the blood of Cape Fear area residents.[25]
In 2020 Michigan adopted drinking water standards for 5 previously unregulated PFAS compounds including HFPO-DA which has a maximum contaminant level (MCL) of 370 parts per trillion (ppt). Two previously regulated PFAS compounds PFOA and PFOS had their acceptable limits lowered to 8 ppt and 16 ppt respectively.[26][27]
In 2022 Virginia's Roanoke River had become contaminated by GenX at levels reported to be 1.3 million parts per trillion.[28]
In June 2022 the U.S. Environmental Protection Agency (EPA) published drinking water health advisories, which are non-regulatory technical documents, for GenX and PFBS.[30][31] The lifetime health advisories and health effects support documents assist federal, state, tribal, and local officials and managers of drinking water systems in protecting public health when these chemicals are present in drinking water.
EPA has listed recommended steps that consumers may take to reduce possible exposure to GenX and other PFAS chemicals.[32]
^Sun, Mei; Arevalo, Elisa; Strynar, Mark; Lindstrom, Andrew; Richardson, Michael; Kearns, Ben; Pickett, Adam; Smith, Chris; Knappe, Detlef R. U. (2016-12-13). "Legacy and Emerging Perfluoroalkyl Substances Are Important Drinking Water Contaminants in the Cape Fear River Watershed of North Carolina". Environmental Science & Technology Letters. 3 (12): 415–419. Bibcode:2016EnSTL...3..415S. doi:10.1021/acs.estlett.6b00398.
^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.
