An organic compound added to rubber, natural fats and oils, food products, gasoline, and lubricating oils to retard oxidation, deterioration, rancidity, and gum formation, respectively. Rubber antioxidants are commonly of an aromatic amine type, such as di-β-naphthylp-phenylenediamine and phenyl-β-naphthylamine 1% or less based on the rubber content of a mixture affords adequate protection. Many antioxidants are substituted phenolic compounds (butylated hydroxyanisole, di-tert-butyl-p-cresol, and propyl gallate). Food antioxidants are effective in very low concentration (not more than 0.01% in animal fats) and not only retard rancidity but protect the nutritional value by minimizing the breakdown of vitamins and essential fatty acids. Sequestering agents, such as citric and phosphoric acids, are frequently employed in antioxidant mixtures to ify the harmful effect of traces of metallic impurities.
