Information relevant for assessing potential adverse health effects from occupational exposure to chlorobenzene (108907) was reviewed and summarized. Topics included physical properties, chemical properties, production levels, industrial uses, occupational exposure levels, toxicokinetics, acute and chronic toxicity, organ system toxicity, immunotoxicity, allergy, genotoxicity, carcinogenicity, teratogenicity, reproductive toxicity, dose/response relationships, and research needs. Studies have indicated that chlorobenzene is absorbed via respiratory and dermal routes and has resulted in headaches, dizziness, somnolence, and dyspeptic disorders in humans chronically exposed. There were no case reports or epidemiological studies available concerned with the potential carcinogenicity of chlorobenzene in humans. There was some limited evidence indicating that the compound is genotoxic and that it may induce hematopoietic toxicity at relatively moderate doses. Chlorobenzene was not classifiable as a human carcinogen. The author concludes that the central nervous system effects and the hepatotoxic effects should be considered in setting occupational exposure limits.