Denatured alcohol 191923 226176280 2008-07-17T04:31:27Z Xihr 284944 /* Consumption and toxicity */ rm long-uncited claims [[Image:Denaturat.jpg|thumb|A bottle of [[Poland|Polish]] denatured alcohol.]] [[Image:MethylatedSpirits bottle.jpg|right|thumb|Methylated spirits]] '''Denatured alcohol''' is [[ethanol]] which has been rendered toxic or otherwise undrinkable, and in some cases dyed. It is used for purposes such as fuel for spirit burners and camping stoves, and as a [[solvent]]. Traditionally, the main additive was 10% [[methanol]], which gave rise to '''methylated spirits'''. There are diverse industrial uses for ethanol, and therefore literally hundreds of recipes for denaturing ethanol. Typical additives are [[methanol]], [[isopropyl alcohol]], [[acetone]], [[methyl ethyl ketone]], [[methyl isobutyl ketone]], [[denatonium]],<ref name = denaturants>{{cite web | title = Ethanol Denaturants | url = http://www.distill.com/specs/EU2.html | date = 22 Nov 1993 | publisher = The Online Distillery Network}}</ref> and even (uncommonly) [[aviation gasoline]]. In the phrase '''denatured alcohol''', ''denatured'' means "a specific property of ethanol, its usefulness as a [[beverage]], is removed". The ethanol molecule is not [[Denaturation (biochemistry)|denatured]] in the sense that its [[chemical structure]] is altered. There is no [[duty (economics)|duty]] on denatured alcohol in most countries, making it considerably cheaper than pure [[ethanol]]. Consequently, its composition is tightly defined by government regulations which vary between countries. Different additives are used to make it both unpalatable and poisonous in such a way that is hard to rectify through [[distillation]] or other simple processes. Methanol is commonly used for this in part because it has a boiling point close to that of ethanol, and separating it by distillation is difficult, but not impossible as methanol and ethanol form a [[zeotrope|zeotropic]] mixture (the opposite of an [[azeotrope|azeotropic mixture]]). In many countries, it is also required to be [[dye]]d blue or purple with an [[aniline dye]]. The tax-exempt status for denatured alcohol dates from the mid-19th century. For instance the [[United Kingdom]] introduced legislation in 1855 to permit ethanol containing 10% [[Methanol|wood-naphtha]] to be exempt. ==Formulations== There are several grades of denatured alcohol, but the denaturants used are generally similar. The formulation for ''completely denatured alcohol'', according to British regulations<ref>{{cite web | url = http://www.opsi.gov.uk/si/si2005/20051524.htm | title = The Denatured Alcohol Regulations 2005 | year = 2005 | publisher = [[Office of Public Sector Information]]}}</ref> is typical: <blockquote>Completely denatured alcohol must be made in accordance with the following formulation: with every 90 parts by volume of alcohol mix 9.5 parts by volume of wood naphtha or a substitute for wood naphtha and 0.5 parts by volume of crude pyridine, and to the resulting mixture add mineral naphtha (petroleum oil) in the proportion of 3.75 litres to every 1000 litres of the mixture and synthetic organic dyestuff (methyl violet) in the proportion of 1.5 grams to every 1000 litres of the mixture.</blockquote> == Uses == A common use is as a fuel for marine and ultra-light camping (backpacking) [[Portable stove|stoves]]. Its main advantages are its low cost, its ability to be extinguished by water, and its ability to be transported without special containers. However, safety concerns do arise from the near-colourless flame with which alcohol burns. In brightly-lit areas, an alcohol flame can be essentially invisible, creating a potential hazard wherein persons can be burned by contacting flames they cannot see. One notable use is as a sanding aid, as the alcohol helps to more easily remove the excess dust that results from sanding wood, <ref>{{cite web | title=Denatured Alcohol as a Sanding Aid | year=Unknown year | publisher=Woodzone.com | url=http://www.woodzone.com/tips/denatured.htm| accessdate=2006-04-14}}</ref> because it does not open the wood grain the way that water would. Methylated spirits may also be used to kill [[mealybug]]s.<ref>{{cite web | publisher = Succulents.co.za | title = Mealy Bug Treatment and Description | url = http://www.succulents.co.za/succulent-plant-pests/mealy-bug.php | accessdate = 2007-09-30}}</ref> Denatured alcohol is often also used for its solvent properties, for example to remove ink stains from upholstery or clothes. Antiseptic mouthwash such as [[Listerine]] is denatured to avoid being taxed as an alcoholic beverage. Ethanol can be used as a less toxic alternative to methanol in the production of biodiesel fuel. Biodiesel produced using ethanol is properly called fatty acid ethyl ester, whereas biodiesel from methanol is properly referred to as fatty acid methyl ester.<ref>{{cite web | publisher = University of Idaho | title = Transesterification Process to Manufacture Ethyl Ester of Rape Oil | url = http://journeytoforever.org/biofuel_library/EthylEsterofRapeOil.pdf | accessdate = 2008-04-01}}</ref> ==Consumption and toxicity== Despite its poisonous nature, denatured alcohol is sometimes consumed by the desperate or ignorant, which can result in blindness or death. To help prevent this, [[denatonium]] is often added to give the substance an extremely bitter flavor. Substances such as [[pyridine]] help to give the mixture an unpleasant odor, and emetic (vomiting) agents such as [[syrup of ipecac]] may also be included. The toxicity of methanol is due to the accumulation of its [[metabolites]] &mdash; [[formaldehyde]] and [[formic acid]]. Because the metabolic pathways for ethanol and methanol share a common enzyme, [[alcohol dehydrogenase]], ethanol can be used to treat methanol poisoning by blocking the enzyme until the body can excrete enough methanol through the kidneys, lungs and skin. In a documented case, a ship worker poisoned while cleaning out a methanol tank was successfully treated with administration of a good portion of the liquor in the ship's "medicine chest."<ref>{{cite journal | title = A case of percutaneous industrial methanol toxicity | author = Downie, A.; Khattab, T.M.; Malik, M.I.; Samara, I.N. | journal = [[Occupational Medicine]] | volume = 42 | issue = 1 | pages = 47–49 | year = 1992 | doi = 10.1093/occmed/42.1.47 | pmid = 1315171}}</ref> {{See also|Sterno#Cocktail}} {{See also|Harm reduction}} ==References== {{Reflist}} == External links == *[http://www.access.gpo.gov/nara/cfr/waisidx_07/27cfr20_07.html 27 CFR 20, regulations relating to denatured alcohol in the United States] *[http://www.opsi.gov.uk/SI/si1987/Uksi_19872009_en_11.htm Specifications and licensing of methylated spirits in the United Kingdom] [[Category:Alcohols]] [[Category:Alcohol solvents]] [[da:Husholdningssprit]] [[de:Vergällung]] [[fr:Alcool dénaturé]] [[nl:Spiritus (alcohol)]] [[no:Rødsprit]] [[pl:Denaturat]] [[sv:Teknisk sprit]]