The pulse radiolysis/kinetic absorption technique has been used to study the reactions of CH7SH with O2, NO, and NO2. Rate constants of 8.5 x 10(-12), 1.9 x 10(-11), and 3.5 x 10(-11) cm3 molecule-1 s-1, respectively, were obtained at 1 atm and 298 K. Absorption spectra due to product species indicated that the reaction with O2 proceeds via addition. There is evidence to suggest that addition is also the pathway for the NO and NO2 reactions.