The toxicology of the food preservatives butylhydroxyanisole (BHA) and butylhydroxytoluene (BHT) as well as the naturally occurring vitamin E (alpha-tocopherol) is described. In high dosages all three compounds induce in animals impairment of blood clotting, which can be explained by an antagonism with vitamin K. Specific toxic effects to the lung have only been observed with BHT. The other described toxic effects of BHA and BHT are less characteristic and often occur only after high dosage and long-term treatment. However, BHA induces in animals tumours of the forestomach, which are dose dependent, whereas BHT induces liver tumours in long-term experiments. Because there is no indication of genotoxicity of BHA and BHT, all published findings agree with the fact that BHA and BHT are tumour promoters. In contrast to BHA and BHT, vitamin E is not carcinogenic. On the other hand, all three antioxidants have also anticarcinogenic properties. The intake of the necessary high doses as for these effects are, however, contraindicated with BHA and BHT because of their carcinogenic effects. The present overview concludes that the concentrations of BHA and BHT nowadays used in food, drugs and cosmetics are probably harmless. In addition, vitamin E can also be used in higher doses without the occurrence of adverse effects.