Sulfur-containing compounds are known to be susceptible to oxidation by aqueous HOCl, but the factors affecting the rates of these reactions are not well-established. Here we report on the kinetics of oxidation of thiosulfate, thiourea, thioglyColate, (methylthio)acetate, tetrathionate, dithiodiglycolate, and dithiodipropionate at 25 degrees C and 0.4 M ionic strength. These reactions obey the 3 general rate law -d[OCl-]/dt = (k(OCl)(-)[Ocl(-)] + k(HOCl)[HOCl])[substrate] with some exceptions: tetrathionate and the two disulfides undergo rate-limiting hydrolysis at high pH, and dithiodiglycolate has an additional term in the rate law that is second order in [substrate]. The reactions of HOCl are believed to have a Cl+ transfer mechanism, and in the case of thiosulfate the rate of hydrolysis of the ClS2O3- intermediate was determined. In the case of thiourea evidence was obtained for thiourea monoxide as a long-lived product. It is shown that sulfite and species with terminal sulfur atoms have k(HOCl) values in the vicinity of 1 x 10(9) M-1 s(-1), while SCN- and thioethers react somewhat more slowly; tetrathionate, trithionate, and disulfides react much more,slowly. Comparison of the rate constants with those for oxidation of these sulfur substrates by H2O2 and [Pt(CN)(4)Cl-2](2-) shows that HOCl reacts a few orders of magnitude more rapidly than [Pt(CN)(4)Cl-2](2-) and similar to 9 orders of magnitude more rapidly than H2O2. Many of the k(HOCl) values are leveled by the high electrophilicity of HOCl. It is proposed that the k(OCl)- values correspond to oxygen-atom transfer mechanisms, as supported by LEERS (linear free energy relationships) relating these rate constants to those for reactions,of H2O2 and [Pt(CN)(4)Cl-2](2-).