Alcoholic beverages, typically containing 3–40% ethanol by volume, have been produced and consumed by humans since pre-historic times for their psychoactive effects. Ethanol is thought to cause harm partly as a result of direct damage to DNA caused by its metabolites. In pregnant women, it causes fetal alcohol syndrome. Ethanol’s toxicity is largely caused by its primary metabolite, acetaldehyde (systematically ethanol) and secondary metabolite, acetic acid. All primary alcohols are broken down into aldehydes then to carboxylic acids whose toxicities are similar to acetaldehyde and acetic acid.