WASTE CHARACTERIZATION Solid and hazardous wastes are chemically and physically characterized by methods of the EPA and the American Society for Testing and Materials (ASTM). The EPA Toxicity Characteristic Leaching Procedure (TCLP) is conducted to determine concentrations of regulated organic and inorganic constituents. Bulk chemical compositions are determined by digestion and analyses using methods described for organic and metal constituents. Digestions and extraction techniques include heating block acid digestion and Soxtec extraction. Physical characterization testing includes ASTM tests such as particle-size distribution (sieve or hydrometer methods), bulk density, and moisture content.