Nine anionic detergents from five general classes (alcohol sulfates, ether alcohol sulfates, sulfated alkanolamides, a-sulfo esters and alkytbenzenesulfonates) were rapidly screened for biodegradability under aerobic and microaerophilic conditions in river water at 25 and 35 C. In decreasing order, thF ease of biodegradation under microaerophilic conditions at 35C was as follows: alcohol sulfates, sulfated alkanolamides, 0~-sulfo fatty acid esters and ether alcohol sulfates. Linear alkylbenzenesulfonate did not degrade.