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Per- and polyfluoroalkyl substances (PFAS[1] or PFASs[2]) are a group of synthetic organofluorine chemical compounds that have multiple fluorine atoms attached to an alkyl chain; there are 7 million such chemicals according to PubChem. [3] PFAS came into use after the invention of Teflon in 1938 to make fluoropolymer coatings and products that ...
This timeline of events related to per- and polyfluoroalkyl substances (PFASs) includes events related to the discovery, development, manufacture, marketing, uses, concerns, litigation, regulation, and legislation, involving the human-made PFASs. The timeline focuses on some perfluorinated compounds, particularly perfluorooctanoic acid (PFOA ...
The food web is a simplified illustration of the various methods of feeding that link an ecosystem into a unified system of exchange. There are different kinds of consumer–resource interactions that can be roughly divided into herbivory, carnivory, scavenging, and parasitism.
The US Food and Drug Administration has found food packaging materials like fast-food wrappers, microwave popcorn bags and take-out pizza boxes are a major source of dietary exposure to PFAS.
PFAS are associated with cancer, fetal abnormalities, high cholesterol and changes in liver enzymes, among other concerns. Scientists are still investigating the long-term health effects of PFAS ...
Fluorotelomer. Fluorotelomers are fluorocarbon -based oligomers, or telomers, synthesized by telomerization. [1] Some fluorotelomers and fluorotelomer-based compounds are a source of environmentally persistent perfluorinated carboxylic acids such as PFOA and PFNA, while others are under extended investigation.
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.
Polyvinylidene fluoride or polyvinylidene difluoride (PVDF) is a highly non-reactive thermoplastic fluoropolymer produced by the polymerization of vinylidene difluoride. Its chemical formula is (C 2 H 2 F 2) n. PVDF is a specialty plastic used in applications requiring the highest purity, as well as resistance to solvents, acids and hydrocarbons.