Prosulfuron is a broad-spectrum sulfonylurea herbicide approved for use at EU for selective control of broadleaf weeds in corn, sorghum, and cereal grains. It is highly soluble in water and many organic solvents. Prosulfuron is volatile, mobile and has a high potential for leaching to groundwater. Prosulfuron is subject to numerous aryl and aliphatic hydroxylation reactions in microbial cultures, plants, and animals. Other degradative reactions include O-demethylation of the triazinyl methoxy group and cleavage of the sulfonylurea linkage of the parent herbicide and hydroxylated metabolites. It is generally moderately persistent in soil systems but can very persistent in aquatic systems. It is moderately toxic to mammals birds, honeybees, earthworms and fish but is not expected to bioaccumulate. Prosulfuron has rapidly eliminated in mammals. In rats treated with subtoxic doses of Prosulfuron 90% of the oral dose excreted within 48 hours. No significant residues were found in tissues collected 7 days after dosing, and unmetabolized Prosulfuron represented a significant portion of the excreted radiolabelled residues. Prosulfuron is highly toxic to algae and aquatic plants.