Butylated hydroxyanisole

Butylated hydroxyanisole
IUPAC name

2-tert-Butyl-4-hydroxyanisole and 3-tert-butyl-4-hydroxyanisole (mixture)
Other names

BOA; tert-Butyl-4-hydroxyanisole; (1,1-Dimethylethyl)-4-methoxyphenol; tert-Butyl-4-methoxyphenol; Antioxyne B [1]
Identifiers
CAS number 25013-16-5 Y, 8003-24-5, 9009-68-1, 121-00-6, 88-32-4
PubChem 24667
ChemSpider 23068 Y
UNII REK4960K2U Y
ChEMBL CHEMBL502074 N
Jmol-3D images Image 1
Properties
Molecular formula C11H16O2
Molar mass 180.24 g mol−1
Appearance waxy solid
Density 1.0587 g/cm³ at 20 °C
Melting point

48-55 °C, 321-328 K, 118-131 °F
Boiling point

264-270 °C, 537-543 K, 507-518 °F
Solubility in water Insoluble in water; freely soluble in ethanol, methanol, propylene glycol; soluble in fats and oils
Refractive index (nD) 1.5303 at 589.3nm [2]
 N (verify) (what is: Y/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Butylated hydroxyanisole (BHA) is an antioxidant consisting of a mixture of two isomeric organic compounds, 2-tert-butyl-4-hydroxyanisole and 3-tert-butyl-4-hydroxyanisole. It is prepared from 4-methoxyphenol and isobutylene. It is a waxy solid used as a food additive with the E number E320. The primary use for BHA is as an antioxidant and preservative in food, food packaging, animal feed, cosmetics, rubber, and petroleum products.[3] BHA also is commonly used in medicines, such as isotretinoin, lovastatin, and simvastatin, among others.

Contents

Antioxidant properties

Since 1947, BHA has been added to edible fats and fat-containing foods for its antioxidant properties as it prevents food from becoming rancid and developing objectionable odors.[4] Like butylated hydroxytoluene (BHT), the conjugated aromatic ring of BHA is able to stabilize free radicals, sequestering them. By acting as free radical scavengers, further free radical reactions are prevented.

Controversy

Some controversy surrounds the use of BHA in foods. The US National Institutes of Health report that BHA is reasonably anticipated to be a human carcinogen based on evidence of carcinogenicity in experimental animals. In particular, when administered in high doses as part of their diet, BHA causes papillomas and squamous cell carcinomas of the forestomach in rats and Syrian golden hamsters.[5] In mice, there is no carcinogenic effect,[5] and even evidence of a protective effect against the carcinogenicity of other chemicals.[4]

When examining human population statistics, the usual low intake levels of BHA shows no significant association with an increased risk of cancer.[6] The State of California, has, however, listed it as a carcinogen.[7]

See also

References

  1. ^ "BHA and BHT". http://chemistry.about.com/od/foodcookingchemistry/a/bha-bht-preservatives.htm. Retrieved Nov. 20, 2009. 
  2. ^ "SciFinder — Experimental properties for 121-00-6". https://scifinder.cas.org. Retrieved Nov. 20, 2009. 
  3. ^ Hazardous Substances Database, National Library of Medicine
  4. ^ a b Lam, L. K., R. P. Pai and L. W. Wattenberg (1979). "Synthesis and chemical carcinogen inhibitory activity of 2-tert-butyl-4-hydroxyanisole". J Med Chem 22 (5): 569–71. doi:10.1021/jm00191a020. PMID 458807. 
  5. ^ a b Butylated Hydroxyanisole (BHA), CAS No. 25013-16-5, Report on Carcinogens, Eleventh Edition, National Institutes of Health
  6. ^ Botterweck AAM, Vergaen H, GoldBohm RA, KleinJans J, van den Brant PA (2007). "Intake of Butylated Hydroxyanisole and Butylated Hydroxytoluene and Stomach Cancer Risk: Results from Analyses in the Netherlands Cohort Study". Food and Chemical Toxicology 38 (7): 599–605. doi:10.1016/S0278-6915(00)00042-9. PMID 10942321. 
  7. ^ "Known Carcinogens and Reproductive Toxicants (California Proposition 65)". Scorecard. http://scorecard.goodguide.com/chemical-groups/one-list.tcl?short_list_name=p65. Retrieved 2011-05-29.