As an antioxidant, BHT functions by inhibiting the formation of free radicals in fats and oils. Free radicals are unstable molecules that can start a chain reaction of oxidation in fatty foods. BHT acts by donating a hydrogen atom to the free radicals, converting them into more stable products and terminating the free radical chain reaction. This prevents the food from becoming rancid. https://logcla.com/blogs/427398/The-Many-Uses-of-Butylated-Hydroxytoluene-in-Food-Preservation-and