Dioxin may refer to a number of different substances. Most notably: * 1,2-Dioxin or 1,4-dioxin, two unsaturated heterocyclic 6-membered rings in which two carbon atoms have been replaced by oxygen atoms, which gives the

molecular formula A chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as paren ...

C₄H₄O₂. They are unstable. * Dibenzo-1,4-dioxin, also known as dibenzodioxin or dibenzo-''p''-dioxin (molecular formula C₁₂H₈O₂), in which two

benzene Benzene is an Organic compound, organic chemical compound with the Chemical formula#Molecular formula, molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar hexagonal Ring (chemistry), ring with one hyd ...

rings are connected through two oxygen atoms. That is the parent compound of the dioxins (see next in which the dioxins comprise a key part of the class). *

Dioxins and dioxin-like compounds Dioxins and dioxin-like compounds (DLCs) are a group of chemical compounds that are persistent organic pollutants (POPs) in the environmental pollutant, environment. They are mostly by-products of burning or various industrial processes or, in the ...

, a diverse class of polychlorinated chemical compounds, including

polychlorinated dibenzodioxins Polychlorinated dibenzodioxins (PCDDs), or simply dioxins, are a group of long-lived polyhalogenated organic compounds that are primarily anthropogenic, and contribute toxic, persistent organic pollution in the environment. They are commonly ...

(PCDDs) and

dibenzofurans Dibenzofuran (DBF) is a heterocyclic organic compound with the chemical structure shown at right. It is an aromatic compound that has two benzene rings fused to a central furan ring. All the numbered carbon atoms have a hydrogen atom bonded to each ...

(PCDFs), that are persistent organic pollutants and known to exhibit "dioxin-like" toxicity. *

2,3,7,8-Tetrachlorodibenzodioxin 2,3,7,8-Tetrachlorodibenzo-''p-''dioxin (TCDD) is a polychlorinated dibenzo''-p-''dioxin (sometimes shortened, though inaccurately, to simply ''dioxin'') with the chemical formula CHClO. Pure TCDD is a colorless solid with no distinguishable ...

(TCDD), the prototypical and most toxic example of the above class, often referred to simply as "dioxin".

See also