Butylated hydroxytoluene (BHT) is a synthetic antioxidant used as a food preservative to prevent oxidative rancidity in fats and oils.
Chemically designated as 2,6-di-tert-butyl-4-methylphenol, BHT stabilizes free radicals, thereby slowing the degradation of lipids and extending shelf life in products such as snack foods, cereals, chewing gum, and baked goods.
It is also employed in packaging materials and cosmetic and pharmaceutical formulations. BHT is generally recognized as safe (GRAS) by the U.S. Food and Drug Administration when used within prescribed limits, though its safety has been the subject of ongoing evaluation and regulatory variation in different countries.