Under aerobic conditions, flazasulfuron is moderately degraded with a half-life between 5 and 100 days. The major metabolite was DPTU. DTPU reached relatively high RA values up to 60% and degraded slowly with a half-life between 40 to 530 days. DTPP, formed by degradation of DTPU, HTPP, TPSA and ADMP were minor products, which all had a relatively slow degradation. Other identified minor products were HMTU (SSRE-006), HTPU (SSRE-020), GTPS (SSRE-018), HTF (SSRE-021) and DMPU (SSRE-003). Most of these compounds degraded moderately to fast. The metabolic pathway involved rearrangement of the sulfonylurea, resulting in the loss of S02 SO2 and hydrolysis reactions leading to non-extractable bound residues and 14CO2 as terminal products of the metabolism. The breakdown of flazasulfuron performed in sterilized soil described in studies suggested that the metabolism may have occurred without microbial activity. Flazasulfuron is mineralized to a smaller extent.