Metabolism of 1,2,3,4-, 1,2,3,5-, and 1,2,4,5-tetrachlorobenzene in the rat.

Adult male rats were given orally single doses of 14C-labeled 1,2,3,4-, 1,2,3,5-, or 1,2,4,5-tetrachlorobenzene (TCB) at 10 mg/kg body weight, and were housed in individual metabolism cages to collect urine and feces for radioassay. For 1,2,3,4- and 1,2,3,5-TCB, approximately 46-51% of the doses were excreted in urine and feces within 48 h after administration. During the same period only 8% of the administered 1,2,4,5-tetrachlorobenzene was excreted. Analysis of urine indicted that the tetrachlorobenzenes were biotransformed to a number of polar compounds. The metabolites for each of the three TCBs in decreasing order of quantities were as follows: 1,2,3,4-TCB, to 2,3,4,5- and 2,3,4,6-tetrachlorophenol and a trace of tetrachlorothiophenol and 2,3,4-trichlorophenol; 1,2,3,5-TCB, to 2,3,4,6-tetrachlorophenol, isomeric hydroxythrichlorothiophenols, and a trichlorophenol; 1,2,4,5-TCB, to 2,3,5,6-tetrachlorophenol, tetrachloroquinol, and a trichlorophenol.