Posted: 21 August 2000

A group of approximately 75 chlorinated hydrocarbons formed as by-products of chemical reactions involving chlorine (Cl) and hydrocarbons. Dioxins appear as manufacturing impurities in some herbicides, wood preservatives and disinfectants, and are released into the environment during the incineration of chlorine-based plastics or as a result of the chlorine bleaching process in the pulp and paper mills. They are also released in industrial processes such as steel making. Dioxins are persistent chemicals, accumulating in soil and human fatty tissue. Health effects are varied and complex, ranging from skin problems, such as chloracne, to cancers, birth defects and serious immunology, neurological and behavioural problems.