Butylated hydroxytoluene 84808 225269006 2008-07-12T20:15:13Z SmackBot 433328 Date the maintenance tags or general fixes {{Chembox new | Name = Butylated hydroxytoluene | ImageFile = 2,6-bis(1,1-dimethylethyl)-4-methylphenol.svg | ImageSize = 200px | ImageName = Butylated hydroxytoluene | IUPACName = 2,6-bis(1,1-dimethylethyl)-4-methylphenol | OtherNames = 2,6-di-''tert''-butyl-4-methylphenol; 2,6-di-''tert''-butyl-''p''-cresol (DBPC); butylated hydroxytoluene; BHT | Section1 = {{Chembox Identifiers | CASNo = 128-37-0 | EINECS = 204-881-4 | RTECS = GO7875000 }} | Section2 = {{Chembox Properties | Formula = C<sub>15</sub>H<sub>24</sub>O | MolarMass = 220.35 g/mol | Appearance = white powder | Density = 1.048 g/cm³, solid | Solubility = insol. | MeltingPt = 70-73 °C | BoilingPt = 265 °C (538.15 K) | pKa = }} | Section7 = {{Chembox Hazards | ExternalMSDS = [http://ptcl.chem.ox.ac.uk/MSDS/DI/2,6-di-t-butyl-p-cresol.html External MSDS] | MainHazards = Flammable | FlashPt = 127 °C | RPhrases = 22-36 37 38 | SPhrases = 26-36 }} | Section8 = {{Chembox Related | OtherCpds = [[butylated hydroxyanisole]] }} }} '''Butylated hydroxytoluene''' (BHT), also known as '''Butylhydroxytoluene''', is a [[lipophilic]] (fat-soluble) [[organic compound]] that is primarily used as an [[antioxidant]] [[food additive]] ([[E number]] E321) as well as in [[cosmetics]], pharmaceuticals, [[jet fuel]]s, [[rubber]], [[petroleum]] products, and [[embalming]] fluid. ==Chemistry== BHT is produced by [[alkylation]] reaction of [[cresol|''p''-cresol]] with [[isobutylene]]. The species behaves as a synthetic analogue of [[vitamin E]], primarily acting as a terminating agent that suppresses autoxidation, a process whereby unsaturated (usually) organic compounds are attacked by atmospheric oxygen. BHT stops this [[autocatalytic]] reaction by converting peroxy radicals to hydroperoxides. It effects this function by donating a hydrogen atom: :RO<sub>2</sub><sup>.</sup> + ArOH → ROOH + ArO<sup>.</sup> :RO<sub>2</sub><sup>.</sup> + ArO<sup>.</sup> → nonradical products where R is alkyl or aryl, and where ArOH is BHT or related phenolic antioxidants. One can see that each BHT consumes two peroxy radicals.<ref>Burton, G. W.; Ingold, K. U., "Autoxidation of biological molecules. 1. Antioxidant activity of vitamin E and related chain-breaking phenolic antioxidants in vitro", Journal of the American Chemical Society, 1981, volume 103, pp 6472 - 6477. DOI: 10.1021/ja00411a035</ref> In the chemical industry it is added to [[tetrahydrofuran]] and [[diethyl ether]] in order to inhibit the formation of dangerous [[organic peroxide]]s. ==Controversy== Concerns have been raised about the use of BHT in food products.{{Fact|date=September 2007}} The compound has been banned for use in food in [[Japan]] ([[1958]]), [[Romania]], [[Sweden]], and [[Australia]]. The US has barred it from infant foods.{{Fact|date=September 2007}} Some food industries have voluntarily eliminated it from their products. However, BHT is also marketed as a health food supplement in capsule form. In different studies, BHT has been reported to cure some cancers, but to encourage others.{{Fact|date=April 2008}} BHT is well studied because of public concern over synthetic preservatives. BHT was largely removed from food in the 1970s, to be replaced with the less well studied [[Butylated hydroxyanisole|BHA]]. ==References== <references/> ==See also== *[[Butylated hydroxyanisole]] (BHA) ==External links== * [http://bht-coldsores.blogspot.com An experiment on the effectiveness BHT has against herpes & cold sore outbreaks] * [http://chemistry.about.com/library/weekly/aa082101a.htm Why are BHA and BHT in foods? Are they safe?] *[http://ntp.niehs.nih.gov/index.cfm?objectid=070510F7-946E-0334-8C3427E3D9734FD0 Bioassay of BHT, includes structure] *[http://www.inchem.org/documents/icsc/icsc/eics0841.htm BUTYLATED HYDROXYTOLUENE (ICSC)] *[http://www.shadetreephysics.com/bht.htm Butylated Hydroxytoluene (BHT) Antioxidant] [[Category:Antioxidants]] [[Category:Phenols]] [[Category:Fuel antioxidants]] [[Category:Food antioxidants]] [[de:Butylhydroxytoluol]] [[es:BHT]] [[fr:Hydroxytoluène butylé]] [[it:Butilidrossitoluene]] [[hu:Butil-hidroxi-toluol]] [[nl:Butylhydroxytolueen]] [[ja:ジブチルヒドロキシトルエン]] [[pl:Butylowany hydroksytoluen]] [[pt:BHT]] [[ru:Ионол]] [[zh:2,6-二叔丁基對甲酚]]