Definition of furan in English:



mass nounChemistry
  • 1A colourless volatile liquid with a planar unsaturated five-membered ring in its molecule.

    • ‘Many plants make use of furocoumarins, in which a coumarin is bonded to a furan ring, as protective substances.’
    • ‘Several studies have demonstrated that only the 5-nitrofurans are mutagenic and that derivatives with the nitro group outside the furan ring do not show mutagenic activity.’
    • ‘In other words, dioxin and furan production decreases with the increase of chlorine availability.’
    • ‘While a furan unit is part of the polychlorinated dibenzofuran structure, these are very different compounds with different effects.’
    • ‘Cycloadditon of one of the double bonds on either the furan or the pyrone ring of a psoralen molecule forms a monoadduct.’
    • ‘This study, however, stays firmly focussed on the standard for dioxin and furan emissions.’
    • ‘Although these derivatives are not properly nitrofurans, the 2-furylethylene compounds with the nitro group located outside the furan ring are isomers of position of the classical 5-nitrofuran derivatives.’
    • ‘Sediment dioxin and furan levels from some of these open coast sites have been highly variable since 1993.’
    • ‘Prior to the group's meetings to draft the dioxin and furan standards, participants believed that the main point of contention would be over the numerical limits.’
    • ‘Furfural reacts with phenols, ketones, and esters as an aldehyde; removal of the aldehyde group yields furan, which is converted to tetrahydrofuran, used in the manufacture of nylon.’
    • ‘Furan, a colourless, volatile liquid used in some chemical manufacturing industries, causes cancer in animals in studies where animals are exposed to furan at high doses.’
    1. 1.1count noun Any substituted derivative of furan.
      • ‘Dioxins, and furans, are chemical compounds generated as by-products of most forms of combustion, particularly of plastics and rubber.’
      • ‘An adsorption powder for removing mercury and other metals, dioxins, furans and other organic compounds from metal- and organic compound-comtaminated soil and method therefor.’
      • ‘Its chemical composition makes it incapable of producing dioxins or furans when burned.’
      • ‘The compounds are furans, thiophenes and pyrroles substituted by two aryl groups and an aliphatic acid group containing from two to six carbon atoms or a derivative thereof.’
      • ‘This argument was presented in a modified form to the effect that the system of monitoring for dioxins and furans (other objectionable organic pollutants) was unreasonable and contrary to Articles 2 and 8 of the Convention.’
      • ‘According to Marcocchio, and the World Health Organization, dioxins are linked to cancer, birth defects and auto-immune problems, while furans are chemically similar but slightly less toxic.’


Late 19th century: from synonymous furfuran.