Polychlorinated carbazoles (PCCZ) are a group of chlorinated organic compounds. They are derivatives of carbazole and nitrogen analogues of polychlorinated dibenzofurans.
Polychlorinated carbazoles usually occur as a mixture of various isomers. This mixture can have a certain frequency pattern (congener pattern) from which conclusions can be drawn about the causes of formation.
PCCZs are not manufactured purposefully. They are formed under certain conditions as by-products of thermal processes. In environmental samples, mixed halogenated carbazoles are also found.