Waste (By-Products)
Some persistent organic pollutants (POPs) are by-products that were produced unintentionally and released to the environment during combustion or during some chemical processes. For example, dioxins, furans, alpha-HCH, and beta-HCH are never intentionally produced (except for laboratory purposes). Dioxin, for example, one of the original "Dirty Dozen" of the Stockholm Convention, is typically produced during incineration. Two others, PCBs and HCB, are produced both intentionally and unintentionally.
