Alcohol

In chemistry, an alcohol is any organic compound in which the hydroxyl functional group (–OH) is bound to a carbon.[2] The term alcohol originally referred to the primary alcohol ethanol (ethyl alcohol), which is used as a drug and is the main alcohol present in alcoholic beverages. An important class of alcohols, of which methanol and ethanol are the simplest members, includes all compounds for which the general formula is CnH2n+1OH. It is these simple monoalcohols that are the subject of this article.

The suffix -ol appears in the IUPAC chemical name of all substances where the hydroxyl group is the functional group with the highest priority. When a higher priority group is present in the compound, the prefix hydroxy- is used in its IUPAC name. The suffix -ol in non-IUPAC names (such as paracetamol or cholesterol) also typically indicates that the substance is an alcohol. However, many substances that contain hydroxyl functional groups (particularly sugars, such as glucose and sucrose) have names which include neither the suffix -ol, nor the prefix hydroxy-.

Alcohol
Ball-and-stick model of an alcohol molecule (R3COH). The red and grey balls represent the hydroxyl group (-OH). The three "R's" stand for carbon substituents or hydrogen atoms.[1]
Alcohol general
The bond angle between an hydroxyl group (-OH) and a chain of carbon atoms (R)

History

Alcohol distillation likely originated in India. During 2000 BCE, people of India used an alcoholic drink called Sura.[3] Alcohol distillation was known to Islamic chemists as early as the eighth century.[4][5]

The Arab chemist, al-Kindi, unambiguously described the distillation of wine in a treatise titled as "The Book of the chemistry of Perfume and Distillations".[6][7][8]

The Persian physician, alchemist, polymath and philosopher Rhazes (854 CE – 925 CE)[9] is credited with the discovery of ethanol.[10][11]

Nomenclature

Etymology

The word "alcohol" is from the Arabic kohl (Arabic: الكحل‎, translit. al-kuḥl), a powder used as an eyeliner.[12] Al- is the Arabic definite article, equivalent to the in English. Alcohol was originally used for the very fine powder produced by the sublimation of the natural mineral stibnite to form antimony trisulfide Sb
2
S
3
. It was considered to be the essence or "spirit" of this mineral. It was used as an antiseptic, eyeliner, and cosmetic. The meaning of alcohol was extended to distilled substances in general, and then narrowed to ethanol, when "spirits" was a synonym for hard liquor.[13]

Bartholomew Traheron, in his 1543 translation of John of Vigo, introduces the word as a term used by "barbarous" (Moorish) authors for "fine powder." Vigo wrote: "the barbarous auctours use alcohol, or (as I fynde it sometymes wryten) alcofoll, for moost fine poudre."[14]

The 1657 Lexicon Chymicum, by William Johnson glosses the word as "antimonium sive stibium."[15] By extension, the word came to refer to any fluid obtained by distillation, including "alcohol of wine," the distilled essence of wine. Libavius in Alchymia (1594) refers to "vini alcohol vel vinum alcalisatum". Johnson (1657) glosses alcohol vini as "quando omnis superfluitas vini a vino separatur, ita ut accensum ardeat donec totum consumatur, nihilque fæcum aut phlegmatis in fundo remaneat." The word's meaning became restricted to "spirit of wine" (the chemical known today as ethanol) in the 18th century and was extended to the class of substances so-called as "alcohols" in modern chemistry after 1850.[14]

The term ethanol was invented 1892, combining the word ethane with the "-ol" ending of "alcohol".[16]

Systematic names

IUPAC nomenclature is used in scientific publications and where precise identification of the substance is important, especially in cases where the relative complexity of the molecule does not make such a systematic name unwieldy. In naming simple alcohols, the name of the alkane chain loses the terminal e and adds the suffix -ol, e.g., as in "ethanol" from the alkane chain name "ethane".[17] When necessary, the position of the hydroxyl group is indicated by a number between the alkane name and the -ol: propan-1-ol for CH
3
CH
2
CH
2
OH
, propan-2-ol for CH
3
CH(OH)CH
3
. If a higher priority group is present (such as an aldehyde, ketone, or carboxylic acid), then the prefix hydroxy-is used,[17] e.g., as in 1-hydroxy-2-propanone (CH
3
C(O)CH
2
OH
).[18]

Some examples of simple alcohols and how to name them
CH3–CH2–CH2–OH Propan-2-ol displayed Cyclohexanol displayed 2-methylpropan-1-ol displayed 2-methylbutan-2-ol displayed
Propan-1-ol 2-Propanol Cyclohexanol acsv Isobutanol 2-Methyl-2-butanol FormulaV1-Seite001
n-propyl alcohol,
propan-1-ol, or
1-propanol
isopropyl alcohol,
propan-2-ol, or
2-propanol
cyclohexanol isobutyl alcohol,
2-methylpropan-1-ol, or
2-methyl-1-propanol
tert-amyl alcohol,
2-methylbutan-2-ol, or
2-methyl-2-butanol
A primary alcohol A secondary alcohol A secondary alcohol A primary alcohol A tertiary alcohol

In cases where the OH functional group is bonded to an sp2 carbon on an aromatic ring the molecule is known as a phenol, and is named using the IUPAC rules for naming phenols.[19]

Common names

In other less formal contexts, an alcohol is often called with the name of the corresponding alkyl group followed by the word "alcohol", e.g., methyl alcohol, ethyl alcohol. Propyl alcohol may be n-propyl alcohol or isopropyl alcohol, depending on whether the hydroxyl group is bonded to the end or middle carbon on the straight propane chain. As described under systematic naming, if another group on the molecule takes priority, the alcohol moiety is often indicated using the "hydroxy-" prefix.[20]

Alcohols are then classified into primary, secondary (sec-, s-), and tertiary (tert-, t-), based upon the number of carbon atoms connected to the carbon atom that bears the hydroxyl functional group. (The respective numeric shorthands 1°, 2°, and 3° are also sometimes used in informal settings.[21]) The primary alcohols have general formulas RCH2OH. The simplest primary alcohol is methanol (CH3OH), for which R=H, and the next is ethanol, for which R=CH3, the methyl group. Secondary alcohols are those of the form RR'CHOH, the simplest of which is 2-propanol (R=R'=CH3). For the tertiary alcohols the general form is RR'R"COH. The simplest example is tert-butanol (2-methylpropan-2-ol), for which each of R, R', and R" is CH3. In these shorthands, R, R', and R" represent substituents, alkyl or other attached, generally organic groups.

Type Formula IUPAC Name Common name
Monohydric
alcohols
CH3OH Methanol Wood alcohol
C2H5OH Ethanol Alcohol
C3H7OH Propan-2-ol Isopropyl alcohol,
Rubbing alcohol
C4H9OH Butan-1-ol Butanol,
Butyl alcohol
C5H11OH Pentan-1-ol Pentanol,
Amyl alcohol
C16H33OH Hexadecan-1-ol Cetyl alcohol
Polyhydric
alcohols
C2H4(OH)2 Ethane-1,2-diol Ethylene glycol
C3H6(OH)2 Propane-1,2-diol Propylene glycol
C3H5(OH)3 Propane-1,2,3-triol Glycerol
C4H6(OH)4 Butane-1,2,3,4-tetraol Erythritol,
Threitol
C5H7(OH)5 Pentane-1,2,3,4,5-pentol Xylitol
C6H8(OH)6 hexane-1,2,3,4,5,6-hexol Mannitol,
Sorbitol
C7H9(OH)7 Heptane-1,2,3,4,5,6,7-heptol Volemitol
Unsaturated
aliphatic
alcohols
C3H5OH Prop-2-ene-1-ol Allyl alcohol
C10H17OH 3,7-Dimethylocta-2,6-dien-1-ol Geraniol
C3H3OH Prop-2-yn-1-ol Propargyl alcohol
Alicyclic
alcohols
C6H6(OH)6 Cyclohexane-1,2,3,4,5,6-hexol Inositol
C10H19OH 5-Methyl-2-(propan-2-yl)cyclohexan-1-ol Menthol

Applications

Alcohol by Country
Total recorded alcohol per capita consumption (15+), in litres of pure ethanol[22]

Alcohols have a long history of myriad uses. For simple mono-alcohols, which is the focus on this article, the following are most important industrial alcohols:[23]

  • methanol, mainly for the production of formaldehyde and as a fuel additive
  • ethanol, mainly for alcoholic beverages, fuel additive, solvent
  • 1-propanol, 1-butanol, and isobutyl alcohol for use as a solvent and precursor to solvents
  • C6–C11 alcohols used for plasticizers, e.g. in polyvinylchloride
  • fatty alcohol (C12–C18), precursors to detergents

Methanol is the most common industrial alcohol, with about 12 million tons/y produced in 1980. The combined capacity of the other alcohols is about the same, distributed roughly equally.[23]

Toxicity

With respect to acute toxicity, simple alcohols have low acute toxicities. Doses of several milliliters are tolerated. For pentanols, hexanols, octanols and longer alcohols, LD50 range from 2–5 g/kg (rats, oral). Methanol and ethanol are less acutely toxic. All alcohols are mild skin irritants.[23]

The metabolism of methanol (and ethylene glycol) is affected by the presence of ethanol, which has a higher affinity for liver alcohol dehydrogenase. In this way methanol will be excreted intact in urine.[24][25][26]

Physical properties

In general, the hydroxyl group makes alcohols polar. Those groups can form hydrogen bonds to one another and to most other compounds. Owing to the presence of the polar OH alcohols are more water-soluble than simple hydrocarbons. Methanol, ethanol, and propanol are miscible in water. Butanol, with a four-carbon chain, is moderately soluble.

Because of hydrogen bonding, alcohols tend to have higher boiling points than comparable hydrocarbons and ethers. The boiling point of the alcohol ethanol is 78.29 °C, compared to 69 °C for the hydrocarbon hexane, and 34.6 °C for diethyl ether.

Occurrence in nature

Simple alcohols are found widely in nature. Ethanol is most prominent because it is the product of fermentation, a major energy-producing pathway. The other simple alcohols are formed in only trace amounts. More complex alcohols are pervasive, as manifested in sugars, some amino acids, and fatty acids.

Production

Ziegler and oxo processes

In the Ziegler process, linear alcohols are produced from ethylene and triethylaluminium followed by oxidation and hydrolysis.[23] An idealized synthesis of 1-octanol is shown:

Al(C2H5)3 + 9 C2H4 → Al(C8H17)3
Al(C8H17)3 + 3 O + 3 H2O → 3 HOC8H17 + Al(OH)3

The process generates a range of alcohols that are separated by distillation.

Many higher alcohols are produced by hydroformylation of alkenes followed by hydrogenation. When applied to a terminal alkene, as is common, one typically obtains a linear alcohol:[23]

RCH=CH2 + H2 + CO → RCH2CH2CHO
RCH2CH2CHO + 3 H2 → RCH2CH2CH2OH

Such processes give fatty alcohols, which are useful for detergents.

Hydration reactions

Some low molecular weight alcohols of industrial importance are produced by the addition of water to alkenes. Ethanol, isopropanol, 2-butanol, and tert-butanol are produced by this general method. Two implementations are employed, the direct and indirect methods. The direct method avoids the formation of stable intermediates, typically using acid catalysts. In the indirect method, the alkene is converted to the sulfate ester, which is subsequently hydrolyzed. The direct hydration using ethylene (ethylene hydration)[27] or other alkenes from cracking of fractions of distilled crude oil.

Hydration is also used industrially to produce the diol ethylene glycol from ethylene oxide.

Biological routes

Ethanol is obtained by fermentation using glucose produced from sugar from the hydrolysis of starch, in the presence of yeast and temperature of less than 37 °C to produce ethanol. For instance, such a process might proceed by the conversion of sucrose by the enzyme invertase into glucose and fructose, then the conversion of glucose by the enzyme complex zymase into ethanol (and carbon dioxide).

Several species of the benign bacteria in the intestine use fermentation as a form of anaerobic metabolism. This metabolic reaction produces ethanol as a waste product. Thus, human bodies contain some quantity of alcohol endogenously produced by these bacteria. In rare cases, this can be sufficient to cause "auto-brewery syndrome" in which intoxicating quantities of alcohol are produced.[28][29][30]

Like ethanol, butanol can be produced by fermentation processes. Saccharomyces yeast are known to produce these higher alcohols at temperatures above 75 °F (24 °C). The bacterium Clostridium acetobutylicum can feed on cellulose to produce butanol on an industrial scale.[31]

Substitution

Primary alkyl halides react with aqueous NaOH or KOH mainly to primary alcohols in nucleophilic aliphatic substitution. (Secondary and especially tertiary alkyl halides will give the elimination (alkene) product instead). Grignard reagents react with carbonyl groups to secondary and tertiary alcohols. Related reactions are the Barbier reaction and the Nozaki-Hiyama reaction.

Reduction

Aldehydes or ketones are reduced with sodium borohydride or lithium aluminium hydride (after an acidic workup). Another reduction by aluminiumisopropylates is the Meerwein-Ponndorf-Verley reduction. Noyori asymmetric hydrogenation is the asymmetric reduction of β-keto-esters.

Hydrolysis

Alkenes engage in an acid catalysed hydration reaction using concentrated sulfuric acid as a catalyst that gives usually secondary or tertiary alcohols. The hydroboration-oxidation and oxymercuration-reduction of alkenes are more reliable in organic synthesis. Alkenes react with NBS and water in halohydrin formation reaction. Amines can be converted to diazonium salts, which are then hydrolyzed.

The formation of a secondary alcohol via reduction and hydration is shown:

Preparation of a secondary alcohol
Preparation of a secondary alcohol

Reactions

Deprotonation

With a pKa of around 16–19, they are, in general, slightly weaker acids than water. With strong bases such as sodium hydride or sodium they form salts called alkoxides, with the general formula RO M+.

2 R-OH + 2 NaH → 2 R-ONa+ + 2 H2
2 R-OH + 2 Na → 2 R-ONa+ + H2

The acidity of alcohols is strongly affected by solvation. In the gas phase, alcohols are more acidic than is water.[32]

Nucleophilic substitution

The OH group is not a good leaving group in nucleophilic substitution reactions, so neutral alcohols do not react in such reactions. However, if the oxygen is first protonated to give R−OH2+, the leaving group (water) is much more stable, and the nucleophilic substitution can take place. For instance, tertiary alcohols react with hydrochloric acid to produce tertiary alkyl halides, where the hydroxyl group is replaced by a chlorine atom by unimolecular nucleophilic substitution. If primary or secondary alcohols are to be reacted with hydrochloric acid, an activator such as zinc chloride is needed. In alternative fashion, the conversion may be performed directly using thionyl chloride.[1]

Some simple conversions of alcohols to alkyl chlorides

Some simple conversions of alcohols to alkyl chlorides

Alcohols may, likewise, be converted to alkyl bromides using hydrobromic acid or phosphorus tribromide, for example:

3 R-OH + PBr3 → 3 RBr + H3PO3

In the Barton-McCombie deoxygenation an alcohol is deoxygenated to an alkane with tributyltin hydride or a trimethylborane-water complex in a radical substitution reaction.

Dehydration

Meanwhile, the oxygen atom has lone pairs of nonbonded electrons that render it weakly basic in the presence of strong acids such as sulfuric acid. For example, with methanol:

Acidity & basicity of methanol

Acidity & basicity of methanol

Upon treatment with strong acids, alcohols undergo the E1 elimination reaction to produce alkenes. The reaction, in general, obeys Zaitsev's Rule, which states that the most stable (usually the most substituted) alkene is formed. Tertiary alcohols eliminate easily at just above room temperature, but primary alcohols require a higher temperature.

This is a diagram of acid catalysed dehydration of ethanol to produce ethylene:

DehydrationOfAlcoholWithH-

DehydrationOfAlcoholWithH-

A more controlled elimination reaction is the with carbon disulfide and iodomethane.

Esterification

Alcohol and carboxylic acids react in the so-called Fischer esterification. The reaction usually requires a catalyst, such as concentrated sulfuric acid:

R-OH + R'-CO2H → R'-CO2R + H2O

Other types of ester are prepared in a similar manner – for example, tosyl (tosylate) esters are made by reaction of the alcohol with p-toluenesulfonyl chloride in pyridine.

Oxidation

Primary alcohols (R-CH2OH) can be oxidized either to aldehydes (R-CHO) or to carboxylic acids (R-CO2H). The oxidation of secondary alcohols (R1R2CH-OH) normally terminates at the ketone (R1R2C=O) stage. Tertiary alcohols (R1R2R3C-OH) are resistant to oxidation.

The direct oxidation of primary alcohols to carboxylic acids normally proceeds via the corresponding aldehyde, which is transformed via an aldehyde hydrate (R-CH(OH)2) by reaction with water before it can be further oxidized to the carboxylic acid.

Alcohol to aldehyde to acid
Mechanism of oxidation of primary alcohols to carboxylic acids via aldehydes and aldehyde hydrates

Reagents useful for the transformation of primary alcohols to aldehydes are normally also suitable for the oxidation of secondary alcohols to ketones. These include Collins reagent and Dess-Martin periodinane. The direct oxidation of primary alcohols to carboxylic acids can be carried out using potassium permanganate or the Jones reagent.

See also

Notes

  1. ^ "alcohols". IUPAC Gold Book. Retrieved 16 December 2013.
  2. ^ IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version:  (2006–) "Alcohols". doi:10.1351/goldbook.A00204
  3. ^ Dhawendra Kumar (2012-05-11). Genomics and Health in the Developing World. Oxford University Press. p. 1128. ISBN 9780199705474.
  4. ^ Al-Hassani, Salim; Abattouy, Mohammed. "The Advent of Scientific Chemistry". Muslim Heritage. Retrieved 17 May 2018.
  5. ^ Curzon, George Nathaniel (7 July 2010). "The History of Alcohol in Islam". Coming Anarchy. Retrieved 17 May 2018.
  6. ^ Forbes, R. J. (1970). A Short History of the Art of Distillation. Brill Publishers. p. 87. ISBN 978-9004006171.
  7. ^ Multhauf, Robert (1966). The Origins of Chemistry. London. pp. 204–6.
  8. ^ Hill, Donald Routledge (1993). Islamic science and engineering. Edinburgh University Press. ISBN 9780748604555.
  9. ^ Hitti, Philip K. (1977). History of the Arabs from the earliest times to the present (10th ed.). London: Macmillan Publishers. p. 365. ISBN 978-0-333-09871-4. The most notable medical authors who followed the epoch of the great translators were Persian in nationality but Arab in language: 'Ali al-Tabari, al-Razi, 'Ali ibn-al-'Abbas al-Majusi and ibn-Sina.
  10. ^ Modanlou, Houchang D. (November 2008). "A tribute to Zakariya Razi (865 - 925 AD), an Iranian pioneer scholar" (PDF). Archives of Iranian Medicine. 11 (6): 673–677. PMID 18976043. Retrieved 17 May 2018. Abu Bakr Mohammad Ibn Zakariya al-Razi, known in the West as Rhazes, was born in 865 AD in the ancient city of Rey, Near Tehran. A musician during his youth he became an alchemist. He discovered alcohol and sulfuric acid. He classified substances as plants, organic, and inorganic.
  11. ^ Schlosser, Stefan (May 2011). "Distillation – from Bronze Age till today". Retrieved 17 May 2018. Al-Razi (865–925) was the preeminent Pharmacist and physician of his time [5]. The discovery of alcohol, first to produce acids such as sulfuric acid, writing up extensive notes on diseases such as smallpox and chickenpox, a pioneer in ophthalmology, author of first book on pediatrics, making leading contributions in inorganic and organic chemistry, also the author of several philosophical works.
  12. ^ Harper, Douglas. "Alcohol". Etymonline. MaoningTech. Retrieved 17 May 2018.
  13. ^ Lohninger, H. (21 December 2004). "Etymology of the Word "Alcohol"". VIAS Encyclopedia. Retrieved 17 May 2018.
  14. ^ a b "alcohol, n.". OED Online. Oxford University Press. 15 November 2016.
  15. ^ Johnson, William (1652). Lexicon Chymicum.
  16. ^ Armstrong, Henry E. (8 July 1892). "Contributions to an international system of nomenclature. The nomenclature of cycloids". Proc. Chem. Soc. 8 (114): 128. doi:10.1039/PL8920800127. As ol is indicative of an OH derivative, there seems no reason why the simple word acid should not connote carboxyl, and why al should not connote COH; the names ethanol ethanal and ethanoic acid or simply ethane acid would then stand for the OH, COH and COOH derivatives of ethane.
  17. ^ a b William Reusch. "Alcohols". VirtualText of Organic Chemistry. Archived from the original on 19 September 2007. Retrieved 14 September 2007.
  18. ^ Organic chemistry IUPAC nomenclature. Alcohols Rule C-201.
  19. ^ Organic Chemistry Nomenclature Rule C-203: Phenols
  20. ^ "How to name organic compounds using the IUPAC rules". www.chem.uiuc.edu. THE DEPARTMENT OF CHEMISTRY AT THE UNIVERSITY OF ILLINOIS. Retrieved 14 November 2016.
  21. ^ Reusch, William. "Nomenclature of Alcohols". chemwiki.ucdavis.edu/. Retrieved 17 March 2015.
  22. ^ "Global Status Report on Alcohol 2004" (PDF). Retrieved 28 November 2010.
  23. ^ a b c d e Falbe, Jürgen; Bahrmann, Helmut; Lipps, Wolfgang; Mayer, Dieter, "Alcohols, Aliphatic", Ullmann's Encyclopedia of Industrial Chemistry, Weinheim: Wiley-VCH, doi:10.1002/14356007.a01_279.
  24. ^ Schep LJ, Slaughter RJ, Vale JA, Beasley DM (30 September 2009). "A seaman with blindness and confusion". BMJ. 339: b3929. doi:10.1136/bmj.b3929. PMID 19793790.
  25. ^ Zimmerman HE, Burkhart KK, Donovan JW (1999). "Ethylene glycol and methanol poisoning: diagnosis and treatment". Journal of Emergency Nursing. 25 (2): 116–20. doi:10.1016/S0099-1767(99)70156-X. PMID 10097201.
  26. ^ Lobert S (2000). "Ethanol, isopropanol, methanol, and ethylene glycol poisoning". Critical Care Nurse. 20 (6): 41–7. PMID 11878258.
  27. ^ Lodgsdon J.E. (1994). "Ethanol". In Kroschwitz J.I. Encyclopedia of Chemical Technology. 9 (4th ed.). New York: John Wiley & Sons. p. 820. ISBN 978-0-471-52677-3.
  28. ^ P. Geertinger MD; J. Bodenhoff; K. Helweg-Larsen; A. Lund (1 September 1982). "Endogenous alcohol production by intestinal fermentation in sudden infant death". Zeitschrift für Rechtsmedizin. Springer-Verlag. 89 (3): 167–172. doi:10.1007/BF01873798.
  29. ^ Logan BK, Jones AW (July 2000). "Endogenous ethanol 'auto-brewery syndrome' as a drunk-driving defence challenge". Medicine, Science, and the Law. 40 (3): 206–15. doi:10.1177/002580240004000304. PMID 10976182.
  30. ^ Cecil Adams (20 October 2006). "Designated drunk: Can you get intoxicated without actually drinking alcohol?". The Straight Dope. Retrieved 27 February 2013.
  31. ^ Zverlov, W; Berezina, O; Velikodvorskaya, GA; Schwarz, WH (August 2006). "Bacterial acetone and butanol production by industrial fermentation in the Soviet Union: use of hydrolyzed agricultural waste for biorefinery". Applied Microbiology and Biotechnology. 71 (5): 587–97. doi:10.1007/s00253-006-0445-z. PMID 16685494.
  32. ^ Smith, Michael B.; March, Jerry (2007), Advanced Organic Chemistry: Reactions, Mechanisms, and Structure (6th ed.), New York: Wiley-Interscience, ISBN 0-471-72091-7

References

  • Metcalf, Allan A. (1999). The World in So Many Words. Houghton Mifflin. ISBN 0-395-95920-9.

External links

Alcohol (drug)

Alcohol, also known by its chemical name ethanol, is a psychoactive substance that is the active ingredient in drinks such as beer, wine, and distilled spirits (hard liquor). It is one of the oldest and most common recreational substances, causing the characteristic effects of alcohol intoxication ("drunkenness"). Among other effects, alcohol produces a mood lift and euphoria, decreased anxiety, increased sociability, sedation, impairment of cognitive, memory, motor, and sensory function, and generalized depression of central nervous system function. Ethanol is a type of chemical compound known as an alcohol, and is the only type of alcohol that is found in alcoholic beverages or is commonly used for recreational purposes; other alcohols such as methanol and isopropyl alcohol are toxic.Alcohol has a variety of short-term and long-term adverse effects. Short-term adverse effects include generalized impairment of neurocognitive function, dizziness, nausea, vomiting, and hangover-like symptoms. Alcohol can be addictive to humans, as in alcoholism, and can result in dependence and withdrawal. It can have a variety of long-term adverse effects on health, for instance liver damage, brain damage, and increased risk of cancer. The adverse effects of alcohol on health are most important when it is used in excessive quantities or with heavy frequency. However, some of them, such as increased risk of certain cancers, may occur even with light or moderate alcohol consumption. In high amounts, alcohol may cause loss of consciousness or, in severe cases, death.

Alcohol works in the brain primarily by increasing the effects of a neurotransmitter called γ-aminobutyric acid, or GABA. This is the major inhibitory neurotransmitter in the brain, and by facilitating its actions, alcohol suppresses the activity of the central nervous system. The substance also directly affects a number of other neurotransmitter systems including those of glutamate, glycine, acetylcholine, and serotonin. The pleasurable effects of alcohol ingestion are the result of increased levels of dopamine and endogenous opioids in the reward pathways of the brain. Alcohol also has toxic and unpleasant actions in the body, many of which are mediated by its byproduct acetaldehyde.Alcohol has been produced and consumed by humans for its psychoactive effects for almost 10,000 years. Drinking alcohol is generally socially acceptable and is legal in most countries, unlike with many other recreational substances. However, there are often restrictions on alcohol sale and use, for instance a minimum age for drinking and laws against public drinking and drinking and driving. Alcohol has considerable societal and cultural significance and has important social roles in much of the world. Drinking establishments, such as bars and nightclubs, revolve primarily around the sale and consumption of alcoholic beverages, and parties, festivals, and social gatherings commonly feature alcohol consumption as well. Alcohol use is also related to various societal problems, including driving accidents and fatalities, accidental injuries, sexual assaults, domestic abuse, and violent crime. Currently, alcohol is illegal for sale and consumption in few mostly Middle Eastern countries.

Alcohol by volume

Alcohol by volume (abbreviated as ABV, abv, or alc/vol) is a standard measure of how much alcohol (ethanol) is contained in a given volume of an alcoholic beverage (expressed as a volume percent). It is defined as the number of millilitres (mL) of pure ethanol present in 100 mL (3.4 fl. oz) of solution at 20 °C (68 °F). The number of millilitres of pure ethanol is the mass of the ethanol divided by its density at 20 °C, which is 0.78924 g/mL (105.3 fl oz/gallon). The ABV standard is used worldwide. The International Organization of Legal Metrology has tables of density of water–ethanol mixtures at different concentrations and temperatures.

In some countries, e.g. France, alcohol by volume is often referred to as degrees Gay-Lussac (after the French chemist Joseph Louis Gay-Lussac), although there is a slight difference since the Gay-Lussac convention uses the International Standard Atmosphere value for temperature, 15 °C (59 °F).

Alcohol intoxication

Alcohol intoxication, also known as drunkenness or alcohol poisoning, is the negative behavior and physical effects due to the recent drinking of ethanol (alcohol). Symptoms at lower doses may include mild sedation and poor coordination. At higher doses, there may be slurred speech, trouble walking, and vomiting. Extreme doses may result in a decreased effort to breathe (respiratory depression), coma, or death. Complications may include seizures, aspiration pneumonia, injuries including suicide, and low blood sugar.Alcohol intoxication typically begins after two or more alcoholic drinks. Risk factors include a social situation where heavy drinking is common and a person having an impulsive personality. Diagnosis is usually based on the history of events and physical examination. Verification of events by the people a person was with may be useful. Legally, alcohol intoxication is often defined as a blood alcohol concentration (BAC) of greater than 5.4-17.4 mmol/L (25–80 mg/dL or 0.025-0.080%). This can be measured by blood or breath testing. Alcohol is then broken down at a rate of about 3.3 mmol/L (15 mg/dL) per hour.Management of alcohol intoxication involves supportive care. Typically this includes putting the person in the recovery position, keeping them warm, and making sure they are breathing sufficiently. Gastric lavage and activated charcoal have not been found to be useful. Repeated assessments may be required to rule out other potential causes of a person's symptoms.Alcohol intoxication is very common, especially in the Western world. Most people who drink alcohol have at some time been intoxicated. In the United States acute intoxication directly results in about 2,200 deaths per year, and indirectly more than 30,000 deaths per year. Acute intoxication has been documented throughout history and alcohol remains one of the world's most widespread recreational drugs. Some religions consider alcohol intoxication to be a sin.

Alcoholic drink

An alcoholic drink (or alcoholic beverage) is a drink that contains ethanol, a type of alcohol produced by fermentation of grains, fruits, or other sources of sugar. Drinking alcohol plays an important social role in many cultures. Most countries have laws regulating the production, sale, and consumption of alcoholic beverages. Some countries ban such activities entirely, but alcoholic drinks are legal in most parts of the world. The global alcoholic drink industry exceeded $1 trillion in 2014.Alcohol is a depressant, which in low doses causes euphoria, reduces anxiety, and improves sociability. In higher doses, it causes drunkenness, stupor, unconsciousness, or death. Long-term use can lead to alcohol abuse, cancer, physical dependence, and alcoholism. Alcohol is one of the most widely used recreational drugs in the world with about 33% of people being current drinkers. As of 2016 women on average drink 0.7 drinks and males 1.7 drinks a day. In 2015, among Americans, 86% of adults had consumed alcohol at some point, 70% had drunk it in the last year, and 56% in the last month. Alcoholic drinks are typically divided into three classes—beers, wines, and spirits—and typically their alcohol content is between 3% and 50%.

Discovery of late Stone Age jugs suggest that intentionally fermented drinks existed at least as early as the Neolithic period (cir. 10,000 BC). Many animals also consume alcohol when given the opportunity and are affected in much the same way as humans, although humans are the only species known to produce alcoholic drinks intentionally.

Alcoholism

Alcoholism, also known as alcohol use disorder (AUD), is a broad term for any drinking of alcohol that results in mental or physical health problems. The disorder was previously divided into two types: alcohol abuse and alcohol dependence. In a medical context, alcoholism is said to exist when two or more of the following conditions are present: a person drinks large amounts over a long time period, has difficulty cutting down, acquiring and drinking alcohol takes up a great deal of time, alcohol is strongly desired, usage results in not fulfilling responsibilities, usage results in social problems, usage results in health problems, usage results in risky situations, withdrawal occurs when stopping, and alcohol tolerance has occurred with use. Risky situations include drinking and driving or having unsafe sex, among other things. Alcohol use can affect all parts of the body, but it particularly affects the brain, heart, liver, pancreas and immune system. This can result in mental illness, Wernicke–Korsakoff syndrome, irregular heartbeat, liver cirrhosis and increased cancer risk, among other diseases. Drinking during pregnancy can cause damage to the baby resulting in fetal alcohol spectrum disorders. Women are generally more sensitive than men to the harmful physical and mental effects of alcohol.Environmental factors and genetics are two components associated with alcoholism, with about half the risk attributed to each. Someone with a parent or sibling with alcoholism is three to four times more likely to become an alcoholic themselves. Environmental factors include social, cultural and behavioral influences. High stress levels and anxiety, as well as alcohol's inexpensive cost and easy accessibility, increase the risk. People may continue to drink partly to prevent or improve symptoms of withdrawal. After a person stops drinking alcohol, they may experience a low level of withdrawal lasting for months. Medically, alcoholism is considered both a physical and mental illness. Questionnaires and certain blood tests may both detect people with possible alcoholism. Further information is then collected to confirm the diagnosis.Prevention of alcoholism may be attempted by regulating and limiting the sale of alcohol, taxing alcohol to increase its cost, and providing inexpensive treatment. Treatment may take several steps. Due to medical problems that can occur during withdrawal, alcohol detoxification should be carefully controlled. One common method involves the use of benzodiazepine medications, such as diazepam. These can be either given while admitted to a health care institution or occasionally while a person remains in the community with close supervision. Mental illness or other addictions may complicate treatment. After detoxification, support such as group therapy or support groups are used to help keep a person from returning to drinking. One commonly used form of support is the group Alcoholics Anonymous. The medications acamprosate, disulfiram or naltrexone may also be used to help prevent further drinking.The World Health Organization estimates that as of 2010 there were 208 million people with alcoholism worldwide (4.1% of the population over 15 years of age). In the United States, about 17 million (7%) of adults and 0.7 million (2.8%) of those age 12 to 17 years of age are affected. It is more common among males and young adults, becoming less common in middle and old age. It is the least common in Africa, at 1.1%, and has the highest rates in Eastern Europe, at 11%. Alcoholism directly resulted in 139,000 deaths in 2013, up from 112,000 deaths in 1990. A total of 3.3 million deaths (5.9% of all deaths) are believed to be due to alcohol. It often reduces a person's life expectancy by around ten years. In the United States, it resulted in economic costs of US$224 billion in 2006. Many terms, some insulting and others informal, have been used to refer to people affected by alcoholism; the expressions include tippler, drunkard, dipsomaniac and souse. In 1979, the World Health Organization discouraged the use of "alcoholism" due to its inexact meaning, preferring "alcohol dependence syndrome".

Blood alcohol content

Blood alcohol content (BAC), also called blood alcohol concentration, blood ethanol concentration, or blood alcohol level, is most commonly used as a metric of alcohol intoxication for legal or medical purposes.

Blood alcohol concentration is usually expressed as a percentage of ethanol in the blood in units of mass of alcohol per volume of blood or mass of alcohol per mass of blood, depending on the country. For instance, in North America a BAC of 0.10 (0.10% or one tenth of one percent) means that there are 0.10 g of alcohol for every 100 mL of blood.

Bureau of Alcohol, Tobacco, Firearms and Explosives

The Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) is a federal law enforcement organization within the United States Department of Justice. Its responsibilities include the investigation and prevention of federal offenses involving the unlawful use, manufacture, and possession of firearms and explosives; acts of arson and bombings; and illegal trafficking and tax evasion of alcohol and tobacco products. The ATF also regulates via licensing the sale, possession, and transportation of firearms, ammunition, and explosives in interstate commerce. Many of the ATF's activities are carried out in conjunction with task forces made up of state and local law enforcement officers, such as Project Safe Neighborhoods. The ATF operates a unique fire research laboratory in Beltsville, Maryland, where full-scale mock-ups of criminal arson can be reconstructed. The agency is led by Thomas E. Brandon, Acting Director, and Ronald B. Turk, Acting Deputy Director. The ATF has 4,770 employees, and an annual budget of $1.15 billion (2012).

Cirrhosis

Cirrhosis is a condition in which the liver does not function properly due to long-term damage. This damage is characterized by the replacement of normal liver tissue by scar tissue. Typically, the disease develops slowly over months or years. Early on, there are often no symptoms. As the disease worsens, a person may become tired, weak, itchy, have swelling in the lower legs, develop yellow skin, bruise easily, have fluid build up in the abdomen, or develop spider-like blood vessels on the skin. The fluid build-up in the abdomen may become spontaneously infected. Other complications include hepatic encephalopathy, bleeding from dilated veins in the esophagus or dilated stomach veins, and liver cancer. Hepatic encephalopathy results in confusion and may lead to unconsciousness.Cirrhosis is most commonly caused by alcohol, hepatitis B, hepatitis C, and non-alcoholic fatty liver disease. Typically, more than two or three alcoholic drinks per day over a number of years is required for alcoholic cirrhosis to occur. Non-alcoholic fatty liver disease has a number of causes, including being overweight, diabetes, high blood fats, and high blood pressure. A number of less common causes of cirrhosis include autoimmune hepatitis, primary biliary cholangitis, hemochromatosis, certain medications, and gallstones. Diagnosis is based on blood testing, medical imaging, and liver biopsy.Some causes of cirrhosis, such as hepatitis B, can be prevented by vaccination. Treatment partly depends on the underlying cause, but the goal is often to prevent worsening and complications. Avoiding alcohol is recommended in all cases of cirrhosis. Hepatitis B and C may be treatable with antiviral medications. Autoimmune hepatitis may be treated with steroid medications. Ursodiol may be useful if the disease is due to blockage of the bile ducts. Other medications may be useful for complications such as abdominal or leg swelling, hepatic encephalopathy, and dilated esophageal veins. In severe cirrhosis, a liver transplant may be an option.Cirrhosis affected about 2.8 million people and resulted in 1.3 million deaths in 2015. Of these, alcohol caused 348,000, hepatitis C caused 326,000, and hepatitis B caused 371,000. In the United States, more men die of cirrhosis than women. The first known description of the condition is by Hippocrates in the 5th century BCE. The word cirrhosis is from Greek: κίρρωσις; kirrhos κιρρός "yellowish" and -osis (-ωσις) meaning "condition", describing the appearance of a cirrhotic liver.

Delaware

Delaware ( (listen)) is a state located in the Mid-Atlantic region of the United States. It is bordered to the south and west by Maryland, north by Pennsylvania, and east by New Jersey and the Atlantic Ocean. The state takes its name from Thomas West, 3rd Baron De La Warr, an English nobleman and Virginia's first colonial governor.Delaware occupies the northeastern portion of the Delmarva Peninsula. It's the second smallest and sixth least populous state, but the sixth most densely populated. Delaware's largest city is Wilmington. The state is divided into three counties, the lowest number of any state. From north to south, they are New Castle County, Kent County, and Sussex County. While the southern two counties have historically been predominantly agricultural, New Castle County is more industrialized.

Before its coastline was explored by Europeans in the 16th century, Delaware was inhabited by several groups of Native Americans, including the Lenape in the north and Nanticoke in the south. It was initially colonized by Dutch traders at Zwaanendael, near the present town of Lewes, in 1631. Delaware was one of the 13 colonies participating in the American Revolution. On December 7, 1787, Delaware became the first state to ratify the Constitution of the United States, and has since been known as "The First State".

Driving under the influence

Driving under the influence (DUI), driving while impaired/driving while intoxicated (DWI), drunk driving, operating while intoxicated (OWI), operating [a] vehicle under the influence of alcohol or drugs (OVI) in Ohio, drink-driving (UK), or impaired driving (Canada) is currently the crime or offense of driving or operating a motor vehicle while impaired by alcohol or other drugs (including recreational drugs and those prescribed by physicians), to a level that renders the driver incapable of operating a motor vehicle safely.

Ethanol

Ethanol (also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is a chemical compound, a simple alcohol with the chemical formula C2H6O. Its formula can be also written as CH3−CH2−OH or C2H5−OH (an ethyl group linked to a hydroxyl group), and is often abbreviated as EtOH. Ethanol is a volatile, flammable, colorless liquid with a slight characteristic odor. It is a psychoactive substance and is the principal type of alcohol found in alcoholic drinks.

Ethanol is naturally produced by the fermentation of sugars by yeasts or via petrochemical processes, and is most commonly consumed as a popular recreational drug. It also has medical applications as an antiseptic and disinfectant. The compound is widely used as a chemical solvent, either for scientific chemical testing or in synthesis of other organic compounds, and is a vital substance used across many different kinds of manufacturing industries. Ethanol is also used as a clean-burning fuel source.

Fetal alcohol spectrum disorder

Fetal alcohol spectrum disorders (FASDs) are a group of conditions that can occur in a person whose mother drank alcohol during pregnancy. Problems may include an abnormal appearance, short height, low body weight, small head size, poor coordination, low intelligence, behavior problems, and problems with hearing or seeing. Those affected are more likely to have trouble in school, legal problems, participate in high-risk behaviors, and have trouble with alcohol or other drugs. The most severe form of the condition is known as fetal alcohol syndrome (FAS). Other types include partial fetal alcohol syndrome (pFAS), alcohol-related neurodevelopmental disorder (ARND) and alcohol-related birth defects (ARBD). Some accept only FAS as a diagnosis, seeing the evidence as inconclusive with respect to other types.Fetal alcohol spectrum disorders are caused by drinking alcohol during pregnancy. Surveys from the United States have found about 10% of pregnant women have drunk alcohol in the last month, and 20% to 30% drank at some point during the pregnancy. About 4.7% of North American women who are pregnant are alcoholics. The risk of problems depends on the amount consumed and the frequency of consumption as well as when during pregnancy the alcohol is consumed. Other risk factors include an older mother, smoking, and poor diet. There is no known safe amount or safe time to drink during pregnancy. While drinking small amounts of alcohol does not cause abnormalities in the face, it may cause behavioral issues. Alcohol crosses the blood brain barrier and both directly and indirectly affects a developing baby. Diagnosis is based on signs and symptoms in the person.Fetal alcohol spectrum disorders are preventable by avoiding alcohol. For this reason, medical authorities recommend no alcohol during pregnancy or while trying to become pregnant. While the condition is permanent, treatment can improve outcomes. Interventions may include parent-child interaction therapy, efforts to modify child behavior, and possibly medications.FASD is estimated to affect between 2% and 5% of people in the United States and Western Europe. FAS is believed to occur in between 0.2 and 9 per 1000 live births in the United States. In South Africa, some populations have rates as high as 9%. The negative effects of alcohol during pregnancy have been described since ancient times. The lifetime cost per child with FAS was $2,000,000 in 2002 in the US. The term fetal alcohol syndrome was first used in 1973.

Isopropyl alcohol

Isopropyl alcohol (IUPAC name propan-2-ol; commonly called isopropanol or 2-propanol) is a compound with the chemical formula CH3CHOHCH3. It is a colorless, flammable chemical compound with a strong odor. As an isopropyl group linked to a hydroxyl group, it is the simplest example of a secondary alcohol, where the alcohol carbon atom is attached to two other carbon atoms. It is a structural isomer of 1-propanol and ethyl methyl ether.

It is used in the manufacture of a wide variety of industrial and household chemicals, and is a common ingredient in chemicals such as antiseptics, disinfectants and detergents.

Legal drinking age

The legal drinking age is the age at which a person can legally consume alcoholic beverages. These laws cover a wide range of issues and behaviors, addressing when and where alcohol can be consumed. The minimum age alcohol can be legally consumed can be different from the age when it can be purchased in some countries. These laws vary between different countries and many laws have exemptions or special circumstances. Most laws apply only to drinking alcohol in public places with alcohol consumption in the home being mostly unregulated (an exception being the UK, which has a minimum legal age of five for supervised consumption in private places). Some countries also have different age limits for different types of alcoholic drinks.Kazakhstan, Oman, Pakistan, Qatar, Sri Lanka, Tajikistan, Thailand, United Arab Emirates, Federated States of Micronesia, Palau, Paraguay, Solomon Islands, India (certain states), the United States (except U.S. Virgin Islands and Puerto Rico), Yemen (Aden and Sana'a), Japan, Iceland, Canada (certain Provinces and Territories), and South Korea have the highest set drinking ages; however, some of these countries do not have off-premises drinking limits. Austria, Antigua and Barbuda, Belgium, Bermuda, British Virgin Islands, Cuba, Ethiopia, Gibraltar, Luxembourg and Nicaragua have the lowest set drinking ages.The most commonly known reason for the law behind the legal drinking age is the effect on the brain in adolescents. Since the brain is still maturing, alcohol can have a negative effect on the memory and long-term thinking. Alongside that, it can cause liver failure, and create a hormone imbalance in teens due to the constant changes and maturing of hormones during puberty.

Liquor

Liquor (also hard liquor, hard alcohol, spirit, or distilled drink) is an alcoholic drink produced by distillation of grains, fruit, or vegetables that have already gone through alcoholic fermentation. The distillation process purifies the liquid and removes diluting components like water, for the purpose of increasing its proportion of alcohol content (commonly expressed as alcohol by volume, ABV). As liquors contain significantly more alcohol, they are considered "harder" – in North America, the term hard liquor is used to distinguish distilled alcoholic drinks from non-distilled ones.

As examples, this term does not include beverages such as beer, wine, mead, sake, or cider, as they are fermented but not distilled. These all have a relatively low alcohol content, typically less than 15%. Brandy is a liquor produced by the distillation of wine, and has an ABV of over 35%. Other examples of liquors include vodka, baijiu, gin, rum, tequila, mezcal, and whisky. (Also see list of alcoholic drinks, and liquors by national origin.)

Methanol

Methanol, also known as methyl alcohol among others, is a chemical with the formula CH3OH (a methyl group linked to a hydroxyl group, often abbreviated MeOH). Methanol acquired the name wood alcohol because it was once produced chiefly by the destructive distillation of wood. Today, methanol is mainly produced industrially by hydrogenation of carbon monoxide.Methanol is the simplest alcohol, consisting of a methyl group linked to a hydroxyl group. It is a light, volatile, colorless, flammable liquid with a distinctive odor similar to that of ethanol (drinking alcohol). Methanol is however far more toxic than ethanol. At room temperature, it is a polar liquid. With more than 20 million tons produced annually, it is used as a precursor to other commodity chemicals, including formaldehyde, acetic acid, methyl tert-butyl ether, as well as a host of more specialized chemicals.

Prohibition

Prohibition is the act or practice of forbidding something by law; more particularly the term refers to the banning of the manufacture, storage (whether in barrels or in bottles), transportation, sale, possession, and consumption of alcoholic beverages. The word is also used to refer to a period of time during which such bans are enforced.

Prohibition in the United States

Prohibition in the United States was a nationwide constitutional ban on the production, importation, transportation, and sale of alcoholic beverages from 1920 to 1933.

During the nineteenth century, alcoholism, family violence, and saloon-based political corruption prompted prohibitionists, led by pietistic Protestants, to end the alcoholic beverage trade to cure the ill society and weaken the political opposition. One result was that many communities in the late-nineteenth and early-twentieth centuries introduced alcohol prohibition, with the subsequent enforcement in law becoming a hotly debated issue. Prohibition supporters, called "drys", presented it as a victory for public morals and health.

Promoted by the "dry" crusaders, the movement was led by pietistic Protestants and social Progressives in the Prohibition, Democratic, and Republican parties. It gained a national grass roots base through the Woman's Christian Temperance Union. After 1900, it was coordinated by the Anti-Saloon League. Opposition from the beer industry mobilized "wet" supporters from the Catholic and German Lutheran communities. They had funding to fight back, but by 1917–18 the German community had been marginalized by the nation's war against Germany, and the brewing industry was shut down in state after state by the legislatures and finally nationwide under the Eighteenth Amendment to the United States Constitution in 1920. Enabling legislation, known as the Volstead Act, set down the rules for enforcing the federal ban and defined the types of alcoholic beverages that were prohibited. For example, religious use of wine was allowed. Private ownership and consumption of alcohol were not made illegal under federal law, but local laws were stricter in many areas, with some states banning possession outright.

Criminal gangs were able to gain control of the beer and liquor supply for many cities. By the late-1920s a new opposition mobilized nationwide. Wets attacked prohibition as causing crime, lowering local revenues, and imposing "rural" Protestant religious values on "urban" United States. Prohibition ended with the ratification of the Twenty-first Amendment, which repealed the Eighteenth Amendment on December 5, 1933. Some states continued statewide prohibition, marking one of the last stages of the Progressive Era.

Research shows that prohibition reduced overall alcohol consumption by half during the 1920s, and consumption remained below pre-Prohibition levels until the 1940s, suggesting that Prohibition did socialize a significant proportion of the population in temperate habits, at least temporarily. Rates of liver cirrhosis "fell by 50% early in Prohibition and recovered promptly after Repeal in 1933." Criticism remains that Prohibition led to unintended consequences such as a century of Prohibition-influenced legislation and the growth of urban crime organizations, though some scholars have argued that violent crime did not increase dramatically, while others have argued that crime during the Prohibition era was properly attributed to increased urbanization, rather than the criminalization of alcohol use. As an experiment it lost supporters every year, and lost tax revenue that governments needed when the Great Depression began in 1929.

Teetotalism

Teetotalism is the practice or promotion of complete personal abstinence from alcoholic beverages. A person who practices (and possibly advocates) teetotalism is called a teetotaler (plural teetotalers) or is simply said to be teetotal. The teetotalism movement was first started in Preston, England, in the early 19th century. The Preston Temperance Society was founded in 1833 by Joseph Livesey, who was to become a leader of the temperance movement and the author of The Pledge: "We agree to abstain from all liquors of an intoxicating quality whether ale, porter, wine or ardent spirits, except as medicine."

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