tert-Butylhydroquinone

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tert-Butylhydroquinone
Chemical structure of tert-butylhydroquinone
Names
IUPAC name
2-(1,1-Dimethylethyl)-1,4-benzenediol
Other names
TBHQ(i)
Identifiers
1948-33-0 YesY
ChEBI CHEBI:78886 N
ChEMBL ChEMBL242080 N
ChemSpider 15235 YesY
DrugBank DB07726 YesY
Jmol 3D model Interactive image
PubChem 16043
Properties
C10H14O2
Molar mass 166.22 g·mol−1
Appearance Tan powder
Density 1.050 g/mL
Melting point 127 to 129 °C (261 to 264 °F; 400 to 402 K)
Boiling point 273 °C (523 °F; 546 K)
Slightly soluble
Acidity (pKa) 10.80±0.18
Hazards
Main hazards Harmful
Safety data sheet External MSDS
R-phrases R22
S-phrases S26 S27 S28
Flash point 171 °C (340 °F; 444 K)
Related compounds
Related compounds
Butylated hydroxyanisole (BHA)
4-tert-Butylcatechol (TBC)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YesYN ?)
Infobox references

tert-Butylhydroquinone (TBHQ, tertiary butylhydroquinone) is an aromatic organic compound which is a type of phenol. It is a derivative of hydroquinone, substituted with a tert-butyl group.

Applications[edit]

Food preservative[edit]

TBHQ is a highly effective antioxidant.[1] In foods, it is used as a preservative for unsaturated vegetable oils and many edible animal fats.[2] It does not cause discoloration even in the presence of iron, and does not change flavor or odor of the material to which it is added.[1] It can be combined with other preservatives such as butylated hydroxyanisole (BHA). As a food additive, its E number is E319. It is added to a wide range of foods, with the highest limit (1 gram/kg) permitted for frozen fish and fish products. Its primary advantage is extending storage life.

Other[edit]

In perfumery, it is used as a fixative to lower the evaporation rate and improve stability.

It is used industrially as a stabilizer to inhibit autopolymerization of organic peroxides.

It is used as a corrosion inhibitor in biodiesel.[3]

It is also added to varnishes, lacquers, resins, and oil-field additives.

Safety and regulation[edit]

Both the European Food Safety Authority (EFSA)[4] and the United States Food and Drug Administration (FDA) have evaluated TBHQ and determined that it is safe to consume at the concentration allowed in foods.[5] The FDA sets an upper limit of 0.02% of the oil or fat content in foods.[6] At very high doses, it has some negative health effects on lab animals, such as producing precursors to stomach tumors and damage to DNA.[7] A number of studies have shown that prolonged exposure to very high doses of TBHQ may be carcinogenic,[8] especially for stomach tumors.[9] Other studies, however, have shown opposite effects including inhibition against HCA-induced carcinogenesis (by depression of metabolic activation) for TBHQ and other phenolic antioxidants (TBHQ was one of several, and not the most potent).[10] The EFSA considers TBHQ to be noncarcinogenic.[5] A 1986 review of scientific literature concerning the toxicity of TBHQ determined that a wide margin of safety exists between the levels of intake by humans and the doses that produce adverse effects in animal studies.[11] Michigan State University scientists are studying a possible link between TBHQ and food allergies [12]

References[edit]

  1. ^ a b Fats and oils: formulating and processing for applications, Richard D. O'Brien, page 168
  2. ^ Tert-BUTYLHYDROQUINONE (TBHQ), International Programme on Chemical Safety
  3. ^ Almeida, E.S., et al (2011). Behaviour of the antioxidant tert-butylhydroquinone on the storage stability and corrosive character of biodiesel. FUEL 90 (11): 3480-3484. doi:10.1016/j.fuel.2011.06.056
  4. ^ "Food Additive Status List". U.S. Food and Drug Administration. Retrieved June 11, 2016.
  5. ^ a b "Opinion of the Scientific Panel on food additives, flavourings, processing aids and materials in contact with food (AFC) on a request from the Commission related to tertiary-Butylhydroquinone (TBHQ)". European Food Safety Authority, 12 July 2004
  6. ^ 21 C.F.R. § 172.185
  7. ^ Tert-Butylhydroquinone - safety summary from The International Programme on Chemical Safety
  8. ^ Gharavi N, El-Kadi A (2005). "tert-Butylhydroquinone is a novel aryl hydrocarbon receptor ligand". Drug Metab Dispos 33 (3): 365–72. doi:10.1124/dmd.104.002253. PMID 15608132. 
  9. ^ Hirose, Masao; Yada, Hideaki; Hakoi, Kazuo; Takahashi, Satoru; Ito, Nobuyuki; et al. "Modification of carcinogenesis by -tocopherol, t-butylhydro-quinone, propyl gallate and butylated hydroxytoluene in a rat multi-organ carcinogenesis model". Carcinogenesis (Oxford University Press) 14 (1): 2359–2364. doi:10.1093/carcin/14.11.2359. PMID 8242867. Retrieved 2 February 2010. 
  10. ^ Hirose M, Takahashi S, Ogawa K, Futakuchi M, Shirai T, Shibutani M, Uneyama C, Toyoda K, Iwata H (1999). "Chemoprevention of heterocyclic amine-induced carcinogenesis by phenolic compounds in rats". Cancer Lett 143 (2): 173–8. doi:10.1016/S0304-3835(99)00120-2. PMID 10503899. 
  11. ^ Vanesch, G (1986). "Toxicology of tert-butylhydroquinone (TBHQ)". Food and Chemical Toxicology 24 (10–11): 1063–5. doi:10.1016/0278-6915(86)90289-9. PMID 3542758. 
  12. ^ http://msutoday.msu.edu/news/2016/common-additive-may-be-why-you-have-food-allergies/