BHT

BHT, or butylated hydroxytoluene, is a synthetic antioxidant widely used to prevent oxidation in fats, oils, and many processed foods. It is also employed as a stabilizer in cosmetics, pharmaceuticals, and in certain plastics and rubbers. Its chemical name is 2,6-di-tert-butyl-4-methylphenol and its formula is C15H24O. It is a phenolic compound that is poorly soluble in water and mainly soluble in organic solvents.

Mechanism and properties: BHT acts as a radical scavenger, donating hydrogen to lipid peroxyl radicals and interrupting lipid peroxidation. The resulting BHT radical is relatively stable, which slows oxidative damage. The compound can be regenerated by other antioxidants in a formulation, helping to extend its protective effect.

Applications: In foods, BHT is used to delay rancidity in fats and oils, snack foods, cereals, and some meat products. In cosmetics, it helps preserve formulations containing fats and oils. In the plastics and rubber industries, BHT serves as a stabilizer to reduce degradation during processing and storage.

Regulation and safety: BHT is approved for use as an antioxidant in many jurisdictions, typically under specific maximum levels. In the United States, the FDA recognizes BHT as safe when used in accordance with good manufacturing practices; in the European Union, it appears under the code E321 for certain products. Safety evaluations generally find exposure at typical dietary levels to be low-risk, though some animal studies have reported effects at very high doses. Ongoing assessments by national and international authorities continue to review long-term and cumulative exposure.