Alcool à brûler 688037 31711978 2008-07-19T18:20:14Z Fv 35679 /* Usages */ {{Voir homonymes|alcool}} {{ébauche|chimie}} L''''alcool à brûler''' est un [[mélange]] composé d'[[éthanol]] CH<SUB>3</SUB>–CH<SUB>2</SUB>-OH dénaturé avec du [[méthanol]] CH<SUB>3</SUB>OH. L'alcool à brûler est hautement toxique du fait de la présence de méthanol (en général 5 à 10%). == Usages == L'alcool à bruler peut être utilisé pour nettoyer les vitres et les surfaces plastiques. Il est également capable de détacher le vinyle, l'acrylique et différentes colles synthétiques. == Dangers == L'alcool à bruler est la cause de nombreux accidents de barbecue ou feux domestiques, pouvant causer des brûlures profondes. Le danger vient de sa combustion donnant des flammes petites et peu visibles dans les tons bleus. Il est de plus très inflammable et volatile. L'accident le plus fréquent est le retour de flamme, par projection de ce liquide vers une source de chaleur, le jet entre en combustion et fait éclater la bouteille. Préférez donc des allume barbecues solides sous forme de cube (à tenir hors de portée des enfants, pour prévenir les risques d'ingestion) ou éventuellement des allume barbecues liquides spécialement conçus pour cet usage. Comme pour tout produit dangereux le vendeur ou le distributeur est tenu de mettre à disposition une fiche de données de sécurité concernant l'alcool à brûler (conditions d'utilisation, de stockage, d'élimination, etc.). <!-- '''Methylated spirit''' (or '''Meths''') is [[ethanol]] which has been dyed and rendered undrinkable, and is used for purposes such as fuel for spirit burners or as a [[solvent]]. It is a type of [[denatured alcohol]]. Traditionally, the main additive was 10% [[methanol]], which gave rise to its name, but this is not always the case now. There is no [[duty (economics)|duty]] on methylated spirit 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 common for this use in part because it has a boiling point close to that of ethanol, and separating it by distillation is more expensive than the taxes on beverage alcohol). It is also often [[dye]]d blue or purple with an [[aniline dye]], although in [[Australia]] and [[New Zealand]] [[fluorescein]] is used instead. The [[Ireland|Irish]] specification is typical. The following are added to ethanol to make it into methylated spirit. * 9.5 % [[naphtha]] * 0.5 % [[pyridine]] * 0.025 ounce [[methyl violet]] dye per 100 [[gallon]]s of ethanol * 0.375 % [[petroleum oil]] The naphtha and pyridine may be replaced with 10% [[methanol]]. 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% wood-naphtha to be exempt. Despite its poisonous nature, methylated spirit (or "meths") is sometimes drunk, alone or mixed with other substances, by [[Alcoholism|alcoholics]] who have become destitute. As such, there is an argument that the methanol or other poisonous component should be removed because it can cause death and blindness. In Britain, the term "meths" is now sometime used simply to refer to a homeless or destitute person. It is also common to add a [[vomiting]] (emetic) agent, which serves a similar purpose without the fatal side-effects. Likewise, [[denatonium]] adds a bitter taste but will not kill. It is not the methanol itself that is toxic, but the accumulation of its metabolites [[methanal]] and [[methanoic acid]]. Because the metabolic pathways for ethanol and methanol share a common enzyme, alcohol dehydrogenase, ethanol can be used to treat methanol poisoning by blockading the enzyme until the body can excrete enough methanol through the lungs and skin. (In a [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1315171&dopt=Abstract documented case], a shipworker 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.") --><!--- strange but true! ---><!-- Methylated spirits can be used to remove ink stains from upholstery or clothes. --> == Voir aussi == * [[Alcool dénaturé]] * [[Méthanol]] == Lien externe == * [http://www.distill.com/specs/EU2.html Spécification pour l'alcool dénaturé dans divers pays membres de l'Union Européenne] {{Portail chimie}} [[Catégorie:Alcool (chimie)]] [[Catégorie:Solvant]] [[en:Methylated spirit]]