wood alcohol: see methanol.

methyl alcohol: see methanol.

isopropyl alcohol: see isopropanol.

industrial alcohol: see ethanol.

grain alcohol: see ethanol.

fetal alcohol syndrome (FAS), pattern of physical, developmental, and psychological abnormalities seen in babies born to mothers who consumed alcohol during pregnancy. The abnormalities include low birthweight, facial deformities, and mental retardation, and there appears to be an association with impulsive behavior, anxiousness, and an inability on the part of the affected children to understand the consequences of their actions. When some but not all of these abnormalities are present, they are referred to as fetal alcohol effects (FAE). FAE has been observed in children of mothers who drank as little as two drinks per week during pregnancy. FAS affects 1 to 2 babies per 1,000 born worldwide. Many require constant lifelong supervision and end up institutionalized because of dysfunction in the family. FAS was first defined as a syndrome in 1973, although it has been observed for centuries. See also alcoholism.

ethyl alcohol: see ethanol.

denatured alcohol: see ethanol.

alcohol, any of a class of organic compounds with the general formula R-OH, where R represents an alkyl group made up of carbon and hydrogen in various proportions and -OH represents one or more hydroxyl groups. In common usage the term alcohol usually refers to ethanol. The class of alcohols also includes methanol; the amyl, butyl, and propyl alcohols; the glycols; and glycerol. An alcohol is generally classified by the number of hydroxyl groups in its molecule. An alcohol that has one hydroxyl group is called monohydric; monohydric alcohols include methanol, ethanol, and isopropanol. Glycols have two hydroxyl groups in their molecules and so are dihydric. Glycerol, with three hydroxyl groups, is trihydric. The monohydric alcohols are further classified as primary, secondary, or tertiary according to the number of carbon atoms bonded to the carbon atom to which the hydroxyl group is bonded. Many of the properties and reactions characteristic of alcohols are due to the electron charge distribution in the C-O-H portion of the molecule (see chemical bond). Chemical reactions involving the hydroxyl group in an alcohol molecule include: those in which the hydroxyl group is replaced as a whole, e.g., reaction of ethanol with hydrogen iodide to form ethyl iodide and water; those in which only the hydrogen in the hydroxyl group is replaced, e.g., the reaction of ethanol with sodium, an active metal, to form sodium ethoxide and hydrogen; and those in which the carbon-oxygen bond becomes a double bond to form an aldehyde or ketone depending on whether it is a primary or secondary alcohol. Alcohols are generally less volatile, have higher melting points, and are more soluble in water than the corresponding hydrocarbons (in which the -OH group is replaced with hydrogen). For example, at room temperature methanol is a liquid, while methane is a gas.

or methyl alcohol or wood alcohol

Simplest of the alcohols, chemical formula CH₃OH. Once produced by destructive distillation of wood, it is now usually made from the methane in natural gas. Methanol is an important industrial material; its derivatives are used in great quantities for making a vast number of compounds, among them many important synthetic dyes, resins, drugs, and perfumes. It is also used in automotive antifreezes, in rocket fuels, and as a solvent. It is flammable and explosive. A clean-burning fuel, it may substitute (at least in part) for gasoline. It is also used for denaturation of ethanol. A violent poison, it causes blindness and eventually death when drunk.

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or ethyl alcohol or grain alcohol

Organic compound, most important of the alcohols, chemical formula CH₃CH₂OH. Produced by fermentation, it is the intoxicating ingredient in alcoholic beverages. Ethanol for industrial purposes is made by either fermentation or chemical synthesis, then purified by distillation and, to avoid the tax levied on ethyl alcohol for drinking, made unfit to drink (see denaturation) by mixing it with compounds such as methanol, benzene, or kerosene. Ethanol has many uses as a solvent, a raw material, an extraction medium, an antifreeze, an antiseptic, and a gasoline additive and substitute. It is toxic, depressing the central nervous system, and addictive to some persons (see alcoholism). Moderate amounts depress the inhibitory activities of the brain and so appear to stimulate the mind, but larger amounts seriously impair coordination and judgment; excessive consumption can cause coma and death. Taking ethanol in combination with barbiturates or related drugs is especially dangerous.

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Various congenital disorders in a newborn caused by the mother drinking alcohol during pregnancy. The main symptoms are retarded growth, abnormalities of the central nervous system, and certain face and head abnormalities. The child may be mentally retarded. Behavioral problems (e.g., poor concentration, impulsiveness) are sometimes the only obvious symptoms. The syndrome is common in babies born to chronic alcoholics, but health care organizations now commonly recommend that women cease drinking alcohol entirely while pregnant. Other disorders have been linked to alcohol in breast milk.

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Excessive habitual consumption of alcoholic beverages despite physical, mental, social, or economic harm (e.g., cirrhosis, drunk driving and accidents, family strife, frequently missing work). Persons who drink large amounts of alcohol over time become tolerant to its effects. Alcoholism is usually considered an addiction and a disease. The causes are unclear, but there may be a genetic predisposition. It is more common in men, but women are more likely to hide it. Treatment may be physiological (with drugs that cause vomiting and a feeling of panic when alcohol is consumed; not an effective long-term treatment), psychological (with therapy and rehabilitation), or social (with group therapies). Group therapies such as Alcoholics Anonymous are the most effective treatments. Suddenly stopping heavy drinking can lead to withdrawal symptoms, including delirium tremens.

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Any of a class of common organic compounds that contain one or more hydroxyl groups (singlehorzbondOH) attached to one or more of the carbon atoms in a hydrocarbon chain. The number of other substituent groups (R) on that carbon atom make the alcohol a primary (RCH₂OH), secondary (R₂CHOH), or tertiary (R₃COH) alcohol. Many alcohols occur naturally and are valuable intermediates in the synthesis of other compounds because of the characteristic chemical reactions of the hydroxyl group. Oxidation (see oxidation-reduction) of primary alcohols yields aldehydes and (if taken further) carboxylic acids; oxidation of secondary alcohols, ketones. Tertiary alcohols break down on oxidation. Alcohols generally react with carboxylic acids to produce esters. They may also be converted to ethers and olefins. Products of these numerous reactions include fats and waxes, detergents, plasticizers, emulsifiers, lubricants, emollients, and foaming agents. Ethanol (grain alcohol) and methanol (wood alcohol) are the best-known alcohols with one hydroxyl group. Glycols (e.g., ethylene glycol, or antifreeze) contain two hydroxyl groups, glycerol three, and polyols three or more. Seealso alcoholic beverage, alcoholism.

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