Éthanol

Éthanol (chemical formula C2H5OH), also known as ethanol or ethyl alcohol, is a volatile, colorless liquid with a characteristic odor. It is miscible with water and many organic solvents, has a boiling point near 78.4 °C, and is highly flammable. Ethanol is a simple alcohol widely used in industry, medicine, and consumer products.

Commercial production of ethanol occurs by fermentation of sugars by yeast and by catalytic hydration of ethylene. Fermentation-derived ethanol (bioethanol) is produced from biomass such as sugarcane, corn, or cellulosic materials; synthetic routes use petrochemical feedstocks. Purity and denaturation vary according to intended use.

Major uses include alcoholic beverages, where ethanol is the psychoactive ingredient; fuel and fuel additives (blended with gasoline as E10, E85, etc.); solvents for paints, personal care products, and pharmaceuticals; antiseptics and disinfectants; and as an industrial feedstock for chemicals like ethyl esters and acetic acid.

In humans, ethanol acts as a central nervous system depressant. It is metabolized primarily in the liver to acetaldehyde and then acetate. Acute exposure can cause intoxication and, at high doses, poisoning; chronic use can lead to dependence, liver disease, and other health problems. Prenatal exposure is associated with fetal alcohol spectrum disorders.

Ethanol's renewability and lower particulate emissions relative to some fossil fuels are advantages for bioethanol, but lifecycle greenhouse gas impacts depend on feedstock and production methods. Proper storage and handling are required due to flammability and regulatory controls on consumption and sale.