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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 ...
Remediation of per- and polyfluoroalkyl substances refers to the destruction or removal of per- and polyfluoroalkyl substances (PFASs) from the environment. PFASs are a group of synthetic organofluorine compounds, used in diverse products such as non-stick cookware and firefighting foams, that have attracted great concern as persistent organic pollutants.
In 2023, the United States EPA proposed "the first (US national) standard to limit (PFAs) in drinking water;" albeit only six of >12,000 such chemicals were addressed. [11] At high temperatures or in a fire, fluoroelastomers decompose and may release hydrogen fluoride. Any residue must be handled using protective equipment. [citation needed]
The rule will require companies to report leaks of two of the most commonly used per- and polyfluoroalkyl substances, or PFAS, and help pay to clean up existing contamination. The EPA last week ...
Fluorosurfactants (PFAS) reduce surface tension by concentrating at the liquid-air interface due to the lipophobicity of polyfluorocarbons. Chlorofluorocarbons are also perfluorinated compounds, many of which were formerly used as refrigerants ( Freon ) until they were implicated in ozone degradation .
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 ...
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]
Perfluorooctanesulfonic acid (PFOS) (conjugate base perfluorooctanesulfonate) is a chemical compound having an eight-carbon fluorocarbon chain and a sulfonic acid functional group, and thus it is a perfluorosulfonic acid and a perfluoroalkyl substance (PFAS). It is an anthropogenic (man-made) fluorosurfactant, now regarded as a global pollutant.