Chlorinated benzene induction of hepatic porphyria

1,4-Dichlorobenzene and 1,2,4-trichlorobenzene were compared with hexachlorobenzene which is known to cause porphyria. Although hexachlorobenzene administration resulted in a manyfold increase in liver porphyrin levels and urinary excretion of porphyrins, the lesser chlorinated compounds did not do so.