Definition of furan in English:



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

    • ‘Sediment dioxin and furan levels from some of these open coast sites have been highly variable since 1993.’
    • ‘Many plants make use of furocoumarins, in which a coumarin is bonded to a furan ring, as protective substances.’
    • ‘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.’
    • ‘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.’
    • ‘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.’
    • ‘Cycloadditon of one of the double bonds on either the furan or the pyrone ring of a psoralen molecule forms a monoadduct.’
    • ‘In other words, dioxin and furan production decreases with the increase of chlorine availability.’
    • ‘This study, however, stays firmly focussed on the standard for dioxin and furan emissions.’
    • ‘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.’
    • ‘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.’
    • ‘While a furan unit is part of the polychlorinated dibenzofuran structure, these are very different compounds with different effects.’
    1. 1.1[count noun]Any substituted derivative of furan.
      • ‘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.’
      • ‘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.’
      • ‘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.’
      • ‘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.’
      • ‘Dioxins, and furans, are chemical compounds generated as by-products of most forms of combustion, particularly of plastics and rubber.’
      • ‘Its chemical composition makes it incapable of producing dioxins or furans when burned.’


Late 19th century: from synonymous furfuran.