The lower the hepatotoxic potential of modern inhalation anaesthetics, the lower their degree of metabolism. Thus, in contrast to halothane, little hepatotoxicity, or none at all, is expected from the clinical use of isoflurane, desflurane, N2O and xenon. Despite the fact that N2O inhibits methionine synthase, clinically significant bone marrow failure is a rare side effect even after long N2O exposure.