The herbicide isouron [3-(5-tert-butyl-3-isoxazolyl)-1,1-dimethylurea] was mineralized to 31 and 25% in sewage samples at 0.01 and 0.1ppm, respectively, but only 7% was mineralized in river-water samples in a 120-day period. Although most of the radioactivity remained, only 66 to 68% of the initial isouron was found in the river-water samples. Data suggest that isouron was converted mainly to organic compounds, presumably by metabolism. Mineralization occurred in microbial environments

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... g in the seawage. A partial pathway involved in the microbial degradation of isouron in the aqueous environments is proposed. Metabolites, 3-(5-tert-butyl-3-isoxazolyl) -1-methyl-1-formylurea and N-[5-(1, 1dimethyl-2-hydroxyethyl)-3-isoxazolyl]carbamic acid were identified in the sewage samples, these two compounds were not previously found among metabolic products of isouron in soils.