To assist in the development of methods for identifying potentially hazardous wastes, the authors have conducted studies on the extraction of toxicants from several solid waste samples. The extracts were tested for toxicity in the Chinese Hamster Ovary (CHO) Cytotoxicity Test and for mutagenic potential in the Salmonella Histidine Reversion Assay. A new technique was also employed which measured the mutagenicity of neat waste samples by coupling Thin Layer Chromatography (TLC) with the Salmonella Histidine Reversion Assay. The wastes selected for study were coke plant waste, herbicide manufacturing acetone-water effluent, and oil refining waste. Three extraction solvents, ethanol (ETOH), dichloromethane (DCM), and dimethylsulfoxide (DMSO), were chosen based on their solubility and compatibility with bioassay procedures. Each sample was divided into three parts and extracted with each of the three solvents separately. All extracts were tested in the Salmonella assay at five dose levels with five Ames tester strains in the presence and in the absence of an exogenous metabolizing system. DMSO and DCM extracts were utilized for CHO cytotoxicity evaluations. The three neat waste samples and two extracts were assayed with the TLC technique. In addition to the biological assessments, the gross chemical parameters for each sample were determined. Results showed that coke plant waste and herbicide mfg. acetone-water were mutagenic to S. typhimurium with the standard plate test. With the TLC technique, the neat coke plant waste was mutagenic and oil refining waste was toxic. Oil refining waste was also toxic to CHO cells.