dioxins

Noun

dioxin (uncountable)

1. (countable) The unsaturated six-membered heterocycle having four carbon atoms, two oxygen atoms, and two double bonds (molecular formula C₄H₄O₂); 1,2-dioxin and 1,4-dioxin.
   • Dioxin is a specific organic unsaturated non-antiaromatic six-membered ring compound with a chemical formula of C4H4O2. However, the term dioxin is used generically by most authorities to include chlorinated dioxins with furans and many derivative compounds as a complex of at least 75 ubiquitous...2011, Peter Stride, “Limited Bio-diversity and Other Defects of the Immune System in the Inhabitants of the Islands of St Kilda, Scotland”, in Oscar Grillo, Gianfranco Venora, editors, Biodiversity...
2. (countable) The parent compound dibenzo-1,4-dioxin or dibenzo-p-dioxin (molecular formula C₁₂H₈O₂), in which two benzene rings are connected through two oxygen atoms; dibenzodioxin, oxanthrene.
   • Dioxins are not a single chemical. They are a family of chemicals that contain two benzene rings connected by a pair of oxygen molecules. When chlorine atoms are connected to the benzene rings, we have a chlorinated dioxin. The particular chlorinated dioxin of greatest interest and concern is...1992, Ronald E. Gots, “Dioxins and Agent Orange”, in Toxic Risks: Science, Regulation, and Perception, Boca Raton, Fla.; London: Lewis Publishers, CRC Press, →ISBN, page 173
3. (countable) Any of a broad range of toxic or carcinogenic halogenated polycyclic compounds that occur as byproducts of herbicides.
   • The detection of dioxin (specifically, the 2,3,7,8-tetrachlorodibenzo-pdioxin TCDD) in 2,4,5-T raised the question whether dioxin might be present in other herbicides.1974 May, Hazardous Materials Advisory Committee, “Chemistry and Analysis”, in Herbicide Report: Chemistry and Analysis, Environmental Effects, Agricultural and Other Applied Uses (EPA-SAB; 74-001)...
   1. (broadly, specifically) The compound 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; molecular formula C₁₂H₄Cl₄O₂), a persistent organic pollutant of the environment which is generally produced as a byproduct of organic synthesis or when organic materials are burned.
      • The 2,4,5-T used by Courtney and co-workers [...] was contaminated with approximately 30 ppm of 2,3,7,8-tetrachlorodibenzo-p-dioxin (dioxin). [...] The present work describes the results of our teratogenic studies on hamsters with samples of 2,4,5-T containing varying amounts of dioxin and with...1971 November–December, T. F. X. Collins, C. H. Williams, “Teratogenic Studies with 2,4,5-T and 2,4-D in the Hamster”, in Bulletin of Environmental Contamination and Toxicology, volume 6, number 6...