Butylated Hydroxy Toluene (BHT) is a synthetic phenolic compound used as an antioxidant to prevent the oxidation of fats and oils.
Its primary role is to prevent rancidity in foods and to protect ingredients in cosmetics and pharmaceuticals from oxidative degradation.
Chemical Properties:
BHT is a derivative of phenol with two tert-butyl groups positioned ortho to the hydroxyl group.
Its chemical structure allows it to donate a hydrogen atom, neutralizing free radicals, and thus preventing them from reacting with other molecules.
This action effectively interrupts the free radical chain reactions that lead to the deterioration of products.
Physical properties
Appearance: White to pale yellow crystalline solid.
Odor: Slight aromatic odor.
Melting Point: About 70°C (158°F).
Boiling Point: Approximately 265°C (509°F).
Solubility: Poorly soluble in water; highly soluble in fats, oils, and organic solvents like ethanol and acetone.
Density: Around 1.04 g/cm³ at 20°C.
Applications:
1. Food Industry:
BHT is added to foods like cereals, snack foods, and fats to preserve freshness and prevent spoilage by inhibiting the oxidation of fats and oils.
2. Cosmetics:
In cosmetics, BHT is used to protect the integrity of products by preventing the oxidation of fragrances and oils.
3. Pharmaceuticals:
It is used to stabilize drugs and prevent the active ingredients from degrading due to exposure to oxygen.
Safety and Regulatory Aspects:
The use of BHT has been subject to scrutiny and regulatory oversight due to concerns about potential health effects.
While BHT is generally recognized as safe (GRAS) by the U.S. Food and Drug Administration (FDA) when used within prescribed limits, some studies have raised concerns about possible carcinogenicity and endocrine disruption.
However, extensive reviews and studies have often concluded that BHT is safe at the levels commonly used in food and cosmetics.