Constituents of aromatic plants: eucalyptol.

The subacute toxicity studies reported up to now in rats and mice suggested that mice were less susceptible than rats to the toxicity of eucalyptol. In fact, after gavage, it was found toxic in male rats at doses higher than 600 mg/kg while no effect was seen in mice up to 1200 mg/kg. However, the limitations and the quality of the study do not allow the extrapolation of a 'no effect level'. Several reports in rat and brushtail possum show the formation of hydroxylated bicycled products of eucalyptol as main metabolites. Moreover, metabolites which require ring opening have been also detected. Following the accidental exposure of human beings, death was reported in two cases after ingestion of 3.5-5 ml of essential eucalyptus oil, but a number of recoveries have also been described for much higher amounts of oil.