Asian Journal of Chemical Sciences

Polychlorinated dibenzo-p-dioxins and dibenzofurans, together with their brominated and mixed analogues, are unintentionally produced persistent organic pollutants of exceptional toxicity, and the combustion of plastics is a globally significant source. This review integrates the chemistry of dioxin formation from plastics with the full hierarchy of management options across both engineered incineration and uncontrolled open burning, a pairing that existing reviews have addressed only in part. Drawing on accessible peer-reviewed and institutional literature identified through scholarly indexes and appraised critically, the review examines formation mechanisms, feedstock and operating determinants, secondary abatement, residue management, and the governance framework. The evidence indicates that dioxins form predominantly by heterogeneous reactions in the post-combustion temperature window, that chlorine from poly(vinyl chloride) and bromine from flame retardants supply the halogen dioxins require, and that combustion quality and flue-gas cleaning, rather than feedstock halogen content, govern emissions wherever effective control exists. In engineered facilities the combination of good combustion, rapid quenching, sorbent injection and catalytic destruction has cut air emissions by two to three orders of magnitude, shifting the residual burden to dioxin-laden fly ash whose mature management routes immobilise rather than destroy the pollutant. Open burning, the fate of a large share of the world’s plastic waste, emits dioxins at factors thousands of times higher and delivers exposure to the most vulnerable populations, yet lies almost wholly outside the reach of the control technologies and standards that dominate the literature. Brominated and mixed halogenated dioxins remain under-recorded relative to their likely importance. The principal unresolved questions concern the quantification and prevention of open-burning emissions, the regulatory incorporation of brominated congeners, and the maturation of destruction-based residue treatment. The central conclusion is one of proportion: technical effort remains concentrated on the setting that already emits least.