[Indoor air guide values for ethylbenzene].

The German Working Group on Indoor Guidelines of the Federal Environment Agency and the States' Health Authorities is issuing indoor air guide values to protect public health. No human studies are available for health evaluation of ethylbenzene in indoor air. In a well documented subchronic inhalation animal study assessed as reliable, ototoxic effects were observed (LOAECsubchronic = 870 mg/m³). The Working Group assessed a LAEC of 186 mg ethylbenzene/m³ for the endpoint ototoxicity. By applying a factor of 2 to extrapolate from subchronic to chronic exposure, an interspecies factor of 2.5, a factor of 10 for interindividual variability, and a factor of 2 to account for the higher respiratory rate of children compared to adults, a health hazard guide value (RW II) of 2 mg ethylbenzene/m³ is obtained. A precautionary guide value (RW I) of 0.2 mg ethylbenzene/m³ is recommended.