Issue+of+BHT

Synonyms[[image:89910.png align="right" caption="structure of BHT"]]
 BHT;  Ionol;  Ionol (antioxidant);  2,6-Di-tertbutyl-p-cresol;  2,6-Bis(1,1-dimethylethyl)-4-methylphenol;  2,6-Di-tert-butyl-1-hydroxy-4-methylbenzene;  2,6-Di-tertbutyl-p-methylphenol;  3,5-Di-tert-butyl-4-hydroxytoluene;  4-Methyl-2,6-di-tert-butylphenol;  Butylated hydroxytoluene;  Butylhydroxytoluene

Molecular Formula
 C15-H24-O

Physical and Chemical Properties
Physical state and appearance: Solid. (Crystalline solid.) <span style="font-family: Georgia,serif;">Odor: phenolic (Slight.) <span style="font-family: Georgia,serif;">Taste: Tasteless. <span style="font-family: Georgia,serif;">Molecular Weight: 220.36 g/mole <span style="font-family: Georgia,serif;">Color: White to yellowish. <span style="font-family: Georgia,serif;">pH (1% soln/water): Not applicable. <span style="font-family: Georgia,serif;">Boiling Point: 265°C (509°F) <span style="font-family: Georgia,serif;">Melting Point: 70°C (158°F) <span style="font-family: Georgia,serif;">Critical Temperature: Not available. <span style="font-family: Georgia,serif;">Specific Gravity: 1.048 (Water = 1) <span style="font-family: Georgia,serif;">Vapor Pressure: Not applicable. <span style="font-family: Georgia,serif;">Vapor Density: 7.6 (Air = 1) <span style="font-family: Georgia,serif;">Volatility: Not available. <span style="font-family: Georgia,serif;">Odor Threshold: Not available. <span style="font-family: Georgia,serif;">Water/Oil Dist. Coeff.: Not available. <span style="font-family: Georgia,serif;">Ionicity (in Water): Not available. <span style="font-family: Georgia,serif;">Dispersion Properties: See solubility in water, methanol, acetone. <span style="font-family: Georgia,serif;">Solubility:Soluble in methanol, acetone. Insoluble in cold water. Freely soluble in Toluene. Soluble in Isopropanol, Methyl Ethyl Ketone,Cellosolove, Benzene, most hydrocarbon solvents, Ethanol, Petoleum Ether, Liquid Petrolatum, Linseed Oil. Insoluble in alkali

<span style="font-family: Georgia,serif;">Production
<span style="font-family: Georgia,serif;">BHT is prepared by the reaction of [|p-cresol] (4-methylphenol) with [|isobutylene] (2-methylpropene) catalysed by [|sulfuric acid]: <span style="font-family: Georgia,serif;">CH3(C6H4)OH + 2 CH2=C(CH3)2 → ((CH3)3C)2CH3C6H2OH <span style="font-family: Georgia,serif;">Alternatively, BHT is prepared from [|2,6-di-tert-butylphenol] by hydroxymethylation or aminomethylation followed by [|hydrogenolysis]. Approximately 4M kg/y are produced.

<span style="font-family: Georgia,serif;">Reactions
<span style="font-family: Georgia,serif;">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: <span style="font-family: Georgia,serif;">RO2. + ArOH → ROOH + ArO. <span style="font-family: Georgia,serif;">RO2. + ArO. → nonradical products <span style="font-family: Georgia,serif;">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. = =

<span style="font-family: Georgia,serif;">General Description
<span style="font-family: Georgia,serif;"> Butylated hydroxytoluene (BHT), is a white crystalline solid with a faint characteristic odor. It is insoluble in water and in propylene glycol, but is freely soluble in alcohol. It is obtained by alkylation of p-cresol with isobutene or by monobutylation of m,p-cresol mixtures. BHT protect fats from oxidation, which is damage due to exposure of the fats to oxygen. It is used to preserve food odor, color, and flavor. Many packaging materials incorporate BHT.

<span style="font-family: Georgia,serif;"> 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.

<span style="font-family: Georgia,serif;"> This substance is generally recognized as safe for use in food when the total content of antioxidants is not over 0.02 percent of fat or oil content, including essential (volatile) oil content of food, provided the substance is used in accordance with good manufacturing practice.

<span style="font-family: Georgia,serif;"> BHT are often added to potato flakes, dry breakfast cereals, enriched rice, and foods containing animal fats and shortening.

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