Dioxygenated cyclic organic compound, formula C4H8O2, formally a cyclohexane structure in which two diametrically opposed CH2 groups have been replaced by oxygen atoms. Dioxane is widely used as a solvent and as a stabilizer in paints, varnishes, etc; thought to be carcinogenic. Not to be confused with dioxins, formed in the combustion of chlorinated hydrocarbons.