As part of a health-hazard survey on the health risk of hospital cleaning workers from exposure to Lyorthol, a hazard assessment of o-phenylphenol (and its sodium salt), one of the constituents of Lyorthol, has been prepared, In this paper, the physical and chemical characteristics, kinetics and effects of o-phenylphenol and its sodium salt are described and discussed, and an overall, summarizing hazard evaluation is presented. Chemicals/CAS: 2-phenylphenol, 90-43-7; Biphenyl Compounds; Disinfectants