Ethanol is used extensively as a solvent in the manufacture of varnished and perfumes; as a
preservative for biological specimens; in the preparation of essences and flavorings; in many
medicines and drugs; as a disinfectant and in tinctures (e.g., tincture of iodine); and as a fuel and
gasoline additive (see gasohol). Many U.S. automobiles manufactured since 1998 have been
equipped to enable them to run on either gasoline or E85, a mixture of 85% ethanol and 15%
gasoline. E85, however, is not yet widely available.
Denatured, or industrial, alcohol is ethanol to
which poisonous or nauseating substances have been added to prevent its use as a beverage; a
beverage tax is not charged on such alcohol, so its cost is quite low. Medically, ethanol is a soporific,
i.e., sleep-producing; although it is less toxic than the other alcohols, death usually occurs if the concentration of ethanol in the bloodstream exceeds about 5%. Behavioral changes, impairment of vision, or unconsciousness occur at lower concentrations.
The most common use of ethanol as a fuel is in mixtures of motor gasoline. Most of the gasoline sold in the United States contains some fuel ethanol. The exact amount may vary by region. In general, the ethanol content of motor gasoline does not exceed 10% by volume. Gasoline with 10% ethanol content is referred to as E10, and gasoline with 15% ethanol content is called E15. All gasoline vehicles can use E10. Currently, only light-duty vehicles with a model year 2001 or newer can use E15.
Ethanol can be combined with petrol in any concentration up to pure ethanol (E100). Anhydrous ethanol, that is, ethanol without water, can be blended with petrol in varying quantities to reduce the consumption of petroleum fuels, as well as to reduce air pollution.
