Acute toxicity of tetramethylbenzenes: durene, isodurene and prehnitene

Oral LD50 (rat), primary skin irritation (rabbit), cutaneous sensitization (guinea pig) and eye irritation (rabbit) studies were conducted on the three tetramethylbenzene isomers: durene , isodurene and prehnitene. The order of oral toxicity was isodurene greater than prehnitene greater durene. Durene was not a skin irritant, while isodurene and prehnitene each produced a mild positive skin response (erythema). None of the tetramethylbenzenes were skin sensitizers or eye irritants. Durene, isodurene and prehnitene are only slightly toxic on an acute toxicologic basis and only pose an acute health hazard when injested in excessive quantities.