Family of extremely toxic aromatic halogenated hydrocarbon (chemical name 'dibenzo-p-dioxins') which are byproducts of burning polyvinyl chloride (PVC) plastic and manufacture of paper, certain herbicides, and military exfoliants. Being environmentally stable, dioxins can persist in nature (see Bioaccumulation) to enter food chains, and are known to cause kidney and liver cancers and still-births.