Anaerboic biodegration is an important process both in sewage treatment plants and in the natural environment. In general, methods that have been used to study anaerobic biodegradation are not suited to routine examination of a large variety of chemicals, are tedious and time consuming to set up and operate, and often yield equivocal results. An anaerobic biodegradation test method has been proposed in EPA's Draft-Guidance for Premanufacture Notification and is based on that described by Nottingham and Hungate. The prolonged acclimation period, daily manipulations, lack of an indicator to assure maintenance of anaerobic conditions, and relatively imprecise method for measurement of gas production represent drawbacks to this procedure.