- Akira Kawashima (Division of Risk Assessment, Center for Biological Safety and Research, National Institute of Health Sciences / email@example.com)
Division of Risk Assessment, Center for Biological Safety and Research, National Institute of Health Sciences
Toluene had been designated as a priority assessment chemical substance under the Japanese Chemical Substances Control Law (CSCL), and as a result of prioritization, a detailed human health hazard assessment was conducted under Assessment II. We evaluated its general, reproductive, and developmental toxicities, as well as its genotoxicity and carcinogenicity, based on the hazard information provided by domestic and international risk assessment organizations, and the following hazard assessment values for oral and inhalation exposure are proposed. The hazard assessment value of 0.223 mg/kg/day for oral exposure was calculated from a no-observed-adverse-effect level (NOAEL) of 312 mg/kg/day (equal to an average daily dose of 223 mg/kg/day) based on liver and kidney weight increases in a 13-week oral toxicity study in rats by using an uncertainty factor (UF) of 1,000 (interspecies variation: 10, intraspecies variation: 10, and short test period: 10). The hazard assessment value of 0.1 ppm (0.383 mg/m3) for inhalation exposure was calculated from a NOAEL of 45 ppm (equal to a continuous exposure level of 10.7 ppm) based on toxic effects on the central nervous system found in epidemiological investigations of occupational exposure by using a UF of 100 (intraspecies variation: 10 and severe effect: 10).