Subchronic Inhalation Toxicity of Ethylbenzene in Mice, Rats, and Rabbits

Toxicological Profile for Ethylbenzene

“…No adverse histopathological effects were reported in cardiac tissue of rats or mice exposed to 782 ppm or rabbits exposed to 1,610 ppm ethylbenzene for 4 weeks (Cragg et al 1989). Similarly, no cardiovascular effects were observed in rats or mice exposed to 975 ppm ethylbenzene for 90 days (NTP 1992) or in rats exposed to 2,200 ppm, guinea pigs or rabbits exposed to 1,250 ppm, or monkeys exposed to 600 ppm ethylbenzene for 6 months (Wolf et al 1956).…”

“…Inhalation exposure of Fischer 344 rats and B6C3F 1 mice to ethylbenzene for 6 hours/day for 4 days produced lethality at concentrations of 1,200 and 2,400 ppm, respectively, although exposure to concentrations up to 2,400 ppm was not lethal to rabbits (Ethylbenzene Producers Association 1986a). In intermediateduration exposure studies, inhalation exposure of rats and mice to 782 ppm or rabbits to 1,610 ppm ethylbenzene for 4 weeks did not produce lethality (Cragg et al 1989). No mortality was observed in rats or mice exposed to 782 ppm or rabbits exposed to 1,610 ppm ethylbenzene for 4 weeks (Cragg et al 1989) or in rats or mice exposed to 975 ppm ethylbenzene for 90 days (NTP 1992).…”

“…In intermediateduration exposure studies, inhalation exposure of rats and mice to 782 ppm or rabbits to 1,610 ppm ethylbenzene for 4 weeks did not produce lethality (Cragg et al 1989). No mortality was observed in rats or mice exposed to 782 ppm or rabbits exposed to 1,610 ppm ethylbenzene for 4 weeks (Cragg et al 1989) or in rats or mice exposed to 975 ppm ethylbenzene for 90 days (NTP 1992). Survival of male rats, but not female rats or male or female mice, exposed to 750 ppm ethylbenzene for 2 years was significantly decreased (NTP 1999); survival in male rats exposed to 75 or 250 ppm ethylbenzene was not affected.…”

“…Increased liver, kidney, lung, and spleen weights have been observed in animals exposed to ethylbenzene concentrations in the 250-1,000 ppm range (Cragg et al 1989;Elovaara et al 1985;NIOSH 1981;NTP 1992;Wolf et al 1956). However, the changes in organ weight have not been associated with histological alterations.…”

“…However, the changes in organ weight have not been associated with histological alterations. One study (Cragg et al 1989) reported a small, but statistically significant, increase in platelet counts in male rats and leukocyte counts in female rats exposed to 782 ppm ethylbenzene for 4 weeks. Developmental effects have been observed in rats exposed to ≥1,000 ppm.…”