DIOXINS
Unlike most commodity plastics that have only carbon and hydrogen atoms as their main component elements, PVC differs by the addition of chlorine, which increases its compatibility with a wide range of materials and suitability for shaping by a variety of techniques. The addition of the chlorine also leads to one of the major environmental problems associated with PVC – the formation during its manufacture and disposal of dioxins. PVC manufacture, use and disposal have been identified as the single biggest source of dioxin in the environment. During the PVC environmental life cycle, dioxins are formed during the production of the raw material and if a vinyl product ends up in an incinerator. Dioxins refer collectively to a family of 210 different chemicals including dioxins and furans. As a class, dioxins are among the most toxic chemicals known. Many dioxins are carcinogens and highly potent hormone disrupters. They are harmful to animals and fish, do not easily break down in the environment and, therefore, tend to accumulate. Since they are fat-soluble they also tend to bioaccumulation in the food chain. Except for a few laboratory applications, dioxins are never made on purpose, but formed as unwanted wastes and by-products of many reactions involving chlorine, carbon containing molecules and heat.
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