A '''Polyhalogenatedpolyhalogenated compoundscompound''' (PHCs'''PHC''') areis any compoundscompound with multiple substitutions of [[halogen]]s. They are of particular interest and importance because they [[bioaccumulate]] in humans, and comprise a superset of which has many toxic and carcinogenic industrial chemicals as members. [[Polybrominated diphenyl ethers|PBDE]]s, [[Polychlorinated biphenyl|PCB]]s, [[Polychlorinated dibenzodioxins|dioxins (PCDDs)]] and [[Perfluorinated compounds|PFC]]s are all polyhalogenated compounds. They are generally non-[[miscible]] in organic solvents or water, but miscible in some [[hydrocarbons]] from which they often derive.