The health effect of primary concern with regard to exposures of humans to toluene is dysfunction of the central nervous system (CNS). Occupational exposures in the range of 200 to 1,500 ppm have elicited dose-related CNS alterations. Although myelotoxicity was previously attributed to toluene, recent evidence indicated that toluene is not toxic to the blood or bone marrow; myelotoxic effects are considered to have been the result of concurrent exposure to benzene. Available evidence is inadequate for assessing the carcinogenic potential of toluene. Although a 24-month inhalation exposure of rats to 300 ppm did not produce any positive carcinogenic effects, various design deficiencies precluded the usefulness of this study in assessing carcinogenic potential. Toluene has been shown to be non-mutagenic in a battery of microbial, mammalian cell, and whole organism test systems. Animal exposure studies suggest that toluene has low teratogenic potential. However, embryotoxicity has been shown to be an endpoint of concern. The reproductive effects of toluene is a category recommended for additional research. Based on available exposure estimates, the only group at possible high risk are workers exposed at or near the threshold limit value (100 ppm).

Distributed to depository libraries in microfiche. "EPA 600-8-82-008F." "August 1983." Cover title. Includes bibliographical references (pages 18-13-18-18).