BHA is used to preserve fats and oils in food, cosmetics, and pharmaceuticals. It prevents spoilage by reacting with oxygen, thus keeping the oxygen from reacting with fats and oils. It slows the development of off-flavors, odors, and color changes caused by oxidation. Some foods in which BHA is used include: butter, meats, cereals, chewing gum, baked goods, snack foods, dehydrated potatoes, and beer.
see also: BHT.