Butylated Hydroxytoluene (BHT)
Installed 09 Oct 2005. Latest update 17 Oct 2014.
The (fat-soluble) crystaline phenolic antioxidant butylated hydroxytoluene (BHT) was patented in 1947 and received approval for use as a food additive and preservative by the U.S. Food and Drug Administration in 1954.(1)
In 2008 researchers in Taiwan reported finding that BHT is produced naturally by four different kinds of freshwater phytoplankon.(2)
Microscopic Image of BHT (White Crystalline Powder) Showing Individual Crystals
(Courtesy: Jack Reed, Department of Entomology, Mississippi State University)
The following is a somewhat unorthodox stick figure drawing of a BHT molecule.
Stick Diagram and Formula for BHT Molecule
Grey = Carbon; White (and match heads) = Hydrogen; Red = Oxygen
BHT molecules host seven CH3 methyl groups. A methyl group consists of three hydrogen atoms bonded to a carbon atom which is linked to the remainder of a molecule.(3) In the colored stick diagram, the methyl group hydrogen atoms are shown as match heads to remind readers of their roles as hydrogen-donor free-radical scavengers. Their anthromorphic motto might be "Light my fire!" (These last two sentences are written by a non-chemist. It may turn out that something else about the molecule causes it's radical scavenging activity. Input is welcome!)
Since BHT molecules have a single oxygen atom (electronegativity 3.44, compared to 2.20 for hydrogen and 2.55 for carbon) near one tip of their longitudinal axis they may be electrically polarized. I have seen no figures for their dipole moment. [Added 15 Sep 2014.]
Structural comparisons of Antioxidants BHA, BHT and Vitamin E
John J. Manura(4) summarizes a gas chromatography/mass spectrometry (GC/MS) study to measure volatile and semi-volatile organics (including BHA and BHT) in food and pharmaceutical packaging. He cites an earlier study(5) focused on quantifying BHA and BHT in food cereals.
Comparing the Antioxidant Activity of BHT with Two Other Antioxidants
Here is a copy of Table 2 in the article from which the two preceding statements were drawn.
Table 2. Antioxidant activity of Berberis vulgaris extracts, BHT and Vitamin E using the Thiobarbituric acid method (TBA).
Absolute Ethanol extract (BV)
Methanol extract (BV)
Aqueous extract (BV)
(%)(Mean, +/- SD)
27.26 +/- 1.07
16.80 +/- 0.23
6.53 +/- 0.29
20.29 +/- 0.23
6.68 +/- 0.25
The TBA test is a colorimetric technique in which the absorbance of a red chromogen formed between thiobarbituric acid and malondialdehyde is measured.
According to G. Hocman (7), the acceptable daily intake of BHA [and BHT] is at present considered to be 0.6 milligrams per kilogram of body weight. He says, "In spite of their possible tumor-promoting properties they could not be considered overtly toxic. Their pronounced chemoprotective role against some forms of chemical carcinogenesis deserves considerable attention."
Hocman's acceptable daily intake equates to 27 milligrams per 100 pounds of body weight. Crystaline BHT is soluble in animal fat and alcohol (but poorly in water). It is also caustic to body tissues. With these facts in mind, oral injestion of BHT should be done in conjunction with eating a meal containing a fair amount of animal fat. (BHT with a dose of medicinal alcohol might work as well, but perhaps not on an empty stomach).
(2) Production of Natural Butylated Hydroxytoluene as an Antixodant by Fresh Water Phytoplankton - Bakthavachalam Babu and Jiunn-Tzong Wu, J. Phycol., 44, 1447-1454, (2008). [Thanks to Wikipedia.] [New Link 18 May 2013.]
(3) Methyl Group Wikipedia
(4) Manura, John J., "Detection and Identification Of Volatile and Semi-Volatile Organics In Synthetic Polymers Used In Food and Pharmaceutical Packaging," 1994 ASMS Meeting, Chicago, IL., SISWEB.COM Application Note 21-a
(5) Manura, John J., LC/GC, Vol II, No. 2 (2/93) pp. 140-146.
(6) Parichehr Hanachi, Golkho SH, "Using HPLC to Determine the Composition and Antioxidant Activity of Berberis Vulgaris," European Journal of Scientific Research, ISSN 1450-216X, Vol 29, No. 1, pp 47-54. [Abstract]
(7) Hocman G., Chemoprevention of cancer: phenolic antioxidants (BHT, BHA), Int J Biochem, 1988;20(7):639-51. [Abstract]
BHT Preserves Gasoline in Cars [New Link 19 Oct 2013.]
Mass spectra of some miscellaneous artifacts and additives The Lipid Library (Has a mass spectrum for BHT.)
Quantitative determination of BHT in soap products by capillary gas chromatography - M. M. Goldstein, K. Molever and W. P. Lok
BHT's Use as an Antiviral - Herpes, Influenza, HIV?, Newcastle Disease
BHT - Advanced Health & Life Extension website
BHT - Chemical Safety Cards (ICSC):0841 (BHT is combustible!)