Butylated hydroxytoluene

Butylated hydroxytoluene
IUPAC name

2,6-bis(1,1-dimethylethyl)-4-methylphenol
Other names

2,6-di-tert-butyl-4-methylphenol
2,6-di-tert-butyl-p-cresol (DBPC)
3,5-di-tert-butyl-4-hydroxytoluene
BHT
Identifiers
CAS number 128-37-0 Y
ChemSpider 13835296 Y
UNII 1P9D0Z171K Y
EC number 204-881-4
KEGG D02413 Y
ChEBI CHEBI:34247 Y
ChEMBL CHEMBL146 Y
RTECS number GO7875000
Jmol-3D images Image 1
Properties
Molecular formula C15H24O
Molar mass 220.35 g/mol
Appearance White powder
Density 1.048 g/cm3, solid
Melting point

70–73 °C
Boiling point

265 °C (538 K)
Solubility in water 1.1 mg/L (20 °C)[1]
Hazards
MSDS External MSDS
R-phrases 22-36 37 38
S-phrases 26-36
Main hazards Flammable
NFPA 704
1
2
0
Flash point 127 °C
Related compounds
Related compounds Butylated hydroxyanisole
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

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 an antioxidant additive in cosmetics, pharmaceuticals, jet fuels, rubber, petroleum products, electrical transformer oil,[2] and embalming fluid.

Contents

Production

BHT is prepared by the reaction of p-cresol (4-methylphenol) with isobutylene (2-methylpropene) catalysed by sulfuric acid: [3]

CH3(C6H4)OH + 2 CH2=C(CH3)2 → ((CH3)3C)2CH3C6H2OH

Alternatively, BHT is prepared from 2,6-di-tert-butylphenol by hydroxymethylation or aminomethylation followed by hydrogenolysis. Approximately 4M kg/y are produced.

Reactions

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:

RO2. + ArOH → ROOH + ArO.
RO2. + ArO. → 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.[4]

Controversy

In the 1970s, Benjamin Feingold, a San Francisco MD who established the Feingold diet, claimed that BHT could produce hyperactivity in some children. In addition, some controversy surrounds the link of BHT to cancer risk,[5] some studies showing the potential to increase and some showing a decrease in risk.[6][7][8] Some food industries have voluntarily eliminated this additive from their products, and since the 1970s it has been steadily replaced with the less studied BHA. Some foods labeled as "no preservatives" or "no preservatives added" actually contain BHT that was present in the ingredients used to make the product but which does not require disclosure on the label.

BHT is marketed as a health food supplement in capsule form. It has been reported to have anti-viral effects, particularly in use against herpes family viruses and in combination with L-lysine and vitamin C.[9][10][11][12][13][14][15] This latter use has made it into some of the more popular literature.[16][17][18]

Closely related phenol antioxidants exhibit low toxicity. For 2,6-di-tert-butylphenol, the LD50 is greater than 9 g/kg.[3]

References

  1. ^ KEMI - Swedish Chemicals Agency - read the 1'st of Marts 2010 on [1]
  2. ^ Ficha de Datos de Seguridad, Transformador 64, page 1, retrieved December 29, 2008, (español).
  3. ^ a b Helmut Fiege, Heinz-Werner Voges, Toshikazu Hamamoto, Sumio Umemura, Tadao Iwata, Hisaya Miki, Yasuhiro Fujita, Hans-Josef Buysch, Dorothea Garbe, Wilfried Paulus "Phenol Derivatives" Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2002. doi:10.1002/14356007.a19_313 Article Online Posting Date: June 15, 2000.
  4. ^ 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
  5. ^ "Butylated hydroxytoluene (BHT)", IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, 1986;40:161-206.
  6. ^ Kensler TW, Egner PA, Trush MA, Bueding E, Groopman JD, "Modification of aflatoxin B1 binding to DNA in vivo in rats fed phenolic antioxidants, ethoxyquin and a dithiothione", Carcinogenesis, 1985;6(5):759-63.
  7. ^ Williams GM, Iatropoulos MJ, "Inhibition of the hepatocarcinogenicity of aflatoxin B1 in rats by low levels of the phenolic antioxidants butylated hydroxyanisole and butylated hydroxytoluene", Cancer Lett. 1996;104(1):49-53.
  8. ^ Franklin RA, "Butylated hydroxytoluene in sarcoma-prone dogs", Lancet. 1976;1(7972):1296.
  9. ^ Snipes W, Person S, Keith A, Cupp J, "Butylated hydroxytoluene inactivates lipid-containing viruses", Science. 1975;188(4183):64-6.
  10. ^ Brugh M Jr, "Butylated hydroxytoluene protects chickens exposed to Newcastle disease virus. Science", 1977;197(4310):1291-2.
  11. ^ Richards JT, Katz ME, Kern ER, "Topical butylated hydroxytoluene treatment of genital herpes simplex virus infections of guinea pigs", Antiviral Res. 1985;5(5):281-90.
  12. ^ Kim KS, Moon HM, Sapienza V, Carp RI, Pullarkat R, "Inactivation of cytomegalovirus and Semliki Forest virus by butylated hydroxytoluene", J Infect Dis. 1978;138(1):91-4.
  13. ^ Pirtle EC, Sacks JM, Nachman RJ, "Antiviral effectiveness of butylated hydroxytoluene against pseudorabies (Aujeszky’s disease) virus in cell culture, mice, and swine", Am J Vet Res. 1986;47(9):1892-5.
  14. ^ Chetverikova LK, Ki’ldivatov II, Inozemtseva LI, Kramskaia TA, Filippov VK, et al. "Factors of antiviral resistance in the pathogenesis of influenza in mice", Vestn Akad Med Nauk SSSR. 1989;(11):63-8. [in Russian]
  15. ^ Chetverikova LK, Inozemtseva LI, "Role of lipid peroxidation in the pathogenesis of influenza and search for antiviral protective agents" Vestn Ross Akad Med Nauk. 1996;(3):37-40. [in Russian]
  16. ^ Pearson D, Shaw S, "Life Extension: A Practical Scientific Approach", New York, NY: Warner Books, Inc.; 1982:206-207.
  17. ^ Mann JA, Fowkes SW, "Wipe Out Herpes with BHT", Manhattan Beach, Calif: MegaHealth Society; 1983.
  18. ^ Fowkes SW, "The BHT Book", 2010, a free PDF e-publication, downloadable from Project Wellbeing (/steve page).

See also

External links

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