The significance of eight parameters in the characterization of solid wastes is being investigated. Laboratory studies have established methods for the precise and accurate determination of the biochemical oxygen demand of incinerator quench water and the carbon, hydrogen, and nitrogen contents of solid wastes collected before, during, and after processing. The value of determining these four parameters during the development, evaluation, and control of solid waste disposal systems is suggested. Other investigations, designed to elucidate the significance of the determination of the moisture, ash, volatiles, and calorific value of solid wastes, are in progress.