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The United States Environmental Protection Agency defines PFAS in the Drinking Water Contaminant Candidate List 5 as substances that contain "at least one of the following three structures: R−CF 2 −CF(R')R", where both the −CF 2 − and −CF− moieties are saturated carbons, and none of the R groups can be hydrogen; R−CF 2 −O−CF 2 ...
Nonetheless, diverse methods are being tested including sonolysis, electrochemical oxidation, advanced oxidation processes, as well as the use of oxidative enzymes (such as peroxidase and laccase). [2] All of these methods promote the formation of hydroxyl radicals or other oxidizing agents that can oxidize PFAS and break its C−C bonds.
2017 PFAS are on the Government of Canada's 2019 chart of substances prohibited by the Canadian Environmental Protection Act, 1999 (CEPA) and by the Prohibition of Certain Toxic Substances Regulations, 2012. These substances are under these regulations because they are "among the most harmful" and "have been declared toxic to the environment ...
These PFAS would be added to the list of substances identified for consideration in facility assessments and, where necessary, further investigation and cleanup through the corrective action ...
The U.S. Department of Defense's research programs have been trying to define nature and extent of PFAS contamination at U.S. military sites, especially in groundwater. [7] A 2018 report to Congress indicated that "at least 126 drinking water systems on or near military bases" were contaminated with PFAS compounds. [8] [9]
Trifluoroacetic acid is a widely employed acid, used for example in the synthesis of peptides.Its esters are useful in analytical chemistry. Longer-chain perfluoroalkyl carboxylic acids, e.g. with five to nine carbons, are useful fluorosurfactants and emulsifiers used in the production of polytetrafluoroethylene (Teflon) and related fluoropolymers.
The monomers of such perfluoroalkoxy alkane polymers, in common with other per- and polyfluoroalkyl substances, are widespread in the environment due to human production and release of the chemicals; so durable that they are referred to as "forever chemicals"; and have detrimental health concerns not yet fully understood. [10]
A new EU drinking water directive issued in 2020 adopted PFAS limit values. The limit values are 0.1 μg/L for the sum of 20 PFASs including PFHxS, and 0.5 μg/L for the sum of all PFASs. This directive is binding for all EU member nations. It is a minimum directive, and member states can elect to adopt stricter regulations. [19]