1,2-Dichloropropane: metabolism and fate in the rat.

1. The metabolism of 1,2-dichloropropane in the rat has been investigated. The major urinary metabolite has been isolated and identified as N-acetyl-S-(2-hydroxypropyl)cysteine. Two minor metabolites of 1,2-dichloropropane have been identified as beta-chlorolactate and N-acetyl-S-(2,3-dihydroxypropyl)cysteine. 2. The fate of 1-chloro-2-hydroxypropane, a proposed intermediate metabolite of 1,2-dichloropropane, has been investigated. Apart from its known urinary metabolite, N-acetyl-S-(2-hydroxypropyl)cysteine, two oxidative metabolites were detected. These were identified as beta-chlorolactaldehyde and beta-chlorolactate. 3. A pathway is proposed for the metabolism and fate of 1,2-dichloropropane in the rat. This accounts for previous observations made for the fate of radioactivity from administration of 1,2-dichloro[1-14C]propane. 4. The microbial and mammalian metabolism of several halogen-containing foreign compounds is discussed.