Toxicity

Alcohols often have an odor described as 'biting' that 'hangs' in the nasal passages. Ethanol in the form of alcoholic beverages has been consumed by humans since pre-historic times, for a variety of hygienic, dietary, medicinal, religious, and recreational reasons. While it is widely considered relatively harmless or even benefical in small quantities, large enough doses result in a state known as drunkenness or intoxication, which may lead to permanent health damage or death (see ethanol for further discussion).

Other alcohols are substantially more poisonous than ethanol, partly because they take much longer to be metabolized, and often their metabolism produces even more toxic substances. Methanol, or "wood alcohol", for instance, is oxidized by alcohol dehydrogenase enzymes in the liver to the poisonous formaldehyde, which can cause blindness or death. Interestingly, an effective treatment to prevent formaldehyde toxicity after methanol ingestion is to administer ethanol. This will bind to alcohol dehydrogenase, preventing methanol from binding and thus its acting as a substrate.