The observation that sulfite can destroy mutagenic activity in chlorinated waters has important implications with respect to the use of S(IV) in water treatment and sample preservation. The purpose of this study was to evaluate the reaction of sodium sulfite with specific organohalides formed during the chlorination of drinking water. In the first phase, chlorinated fulvic acid solutions were analyzed by closed-loop stripping and GC/MS. Compounds susceptible to decomposition were identified by treating some solutions with sulfite and some without. Phase two included a series of kinetic experiments using pure solutions of chloropicrin, trichloroacetonitrile, dichloroacetonitrile, dibromoacetonitrile, l,l,l-trichloropropanone, chloral, 1,l-dichloropropanone, 2,3,6-trichloroanisole, and 3-chloro-4-(dichloromethyl)-5- hydroxy-2(5H)-furanone (MX). The reactions were found to be first order in the compound and first order in sulfite (specifically, [Sot-]). Each of the reactive compounds gave reduced products (loss of halogen) at rates that suggest the use of sulfite is a feasible means of controlling selected chlorination byproducts in drinking water treatment.