Orthotoluidine is used as an intermediate in the synthesis of herbicides, more than 90 colors and pigments, for synthetic rubber, pharmaceutical products, pesticides, and in the clinical laboratory as an ingredient in reagents for glucose analysis and tissue staining. Significant nonoccupational exposure to orthotoluidine may result from the use of some hair dyes, the local anesthetic prilocaine, or tobacco smoke. Orthotoluidine causes bladder cancer. Its urinary metabolites are orthotoluidine and its conjugates and N-acetyl-ortho-toluidine.