Four groups of 6 male and 6 female Sprague-Dawley rats, maintained on a fixed interval schedule by food reinforcement, were treated by nose-only inhalation for 6 hours with commercial hexane (hexane) at mean (S.D.), concentrations of 0, 873 (36.4), 2974 (39.6) or 9187 (171.8) ppm. The vapor generated was found to contain 15.8 to 16.6% methylcyclopentane and 51.6 to 52.5% n-hexane. The control group was treated similarly in all respects except it received air only. The animal response on the fixed interval 60 second schedule was tested in a 30 minute session immediately after exposure and on post-exposure days 1 and 2. No animals died or were sacrificed due to treatment. There were no toxicologically significant clinical findings attributed to treatment with hexane. The body weights and food intakes of the hexane treatment rats were unaffected by treatment.