Is ethanol genotoxic? A review of the published data

Abstract

A great many studies have been carried out on the toxicology of ethanol, the majority in the context of the effects of the consumption of alcohol in beverages. Published information relevant to the assessment of the possible genotoxic potential of ethanol has been reviewed and evaluated in terms of the safety of ethanol as an industrial chemical, rather than as a component of beverages. The available data on ethanol from standard genotoxicity test methods are incomplete. There is clear evidence that ethanol is not a bacterial or mammalian cell mutagen but in vitro assays for chromosome aberration, although mostly negative, have generally not included exogenous metabolic activation. Evidence from the use of ethanol as a vehicle control suggests that it is not mutagenic or clastogenic in vitro. Reported tests for chromosome aberration induction in vivo are all negative and only a minority of micronucleus tests are positive. Conflicting results have been reported for the dominant lethal assay, although an inter-laboratory study performed to OECD guidelines was negative. There is some evidence that ethanol induces SCE in vivo and can also act as an aneugen at high doses. Many in vivo studies were designed to model alcoholism and used very high doses, sometimes for long periods. Outcomes may have been affected by disturbances of metabolism giving rise to secondary effects. It is concluded that there is no significant evidence that ethanol is a genotoxic hazard according to the criteria normally applied for the purpose of classification and labelling of industrial chemicals. Some degree of genotoxicity may result from excessive alcohol drinking, but this is not considered relevant to any conceivable exposure obtainable by either inhalation or dermal exposure in the workplace.