Degradation of [14C]bensulfuron methyl was rapid; besides 14CO2, IN-R9419, IN-J0290, and IN-D1R84 were the only degradation products found at levels greater than 10% of the applied radioactivity. Degradates present between 5-10% AR were IN-N5297 and IN-F7880. IN-B6895 was identified as a minor degradate less than 2%. The formation of 14CO2, which accompanied the disappearance of bensulfuron methyl, IN-R9419, and the formation (and decline) of the other degradates was indicative that soil microbes played a significant part in the ultimate mineralisation of bensulfuron methyl. In other soil degradation studies, no 14CO2 was observed to form from [14C]bensulfuron methyl if soils were sterilised prior to treatment (Friedman, 1984; Yordy, 1987). The results obtained in this study indicate that bensulfuron methyl should readily degrade in a microbially viable soil, with eventual mineralisation to CO2.