Butylated hydroxyanisole (BHA) is an antioxidant consisting of a mixture of two isomeric organic compounds, 2-tert-butyl-4-hydroxyanisole and 3-tert-butyl-4-hydroxyanisole. It is prepared from 4-methoxyphenol and isobutylene. It is a waxy solid used as a food additive with the E number E320. The primary use for BHA is as an antioxidant and preservative in food, food packaging, animal feed, cosmetics, rubber, and petroleum products. BHA also is commonly used in medicines, such as isotretinoin, lovastatin, and simvastatin, among others.
BHA has been added to edible fats and fat-containing foods for its antioxidant properties as it prevents rancidification of food which creates objectionable odors. Like butylated hydroxytoluene (BHT), the conjugated aromatic ring of BHA is able to stabilize free radicals, sequestering them. By acting as free radical scavengers, further free radical reactions are prevented.
A synthetic phenolic antioxidant Butylated Hydroxyanisole (BHA) is a commonly used fat soluble food preservative since 1947, with a broad biological activities. It prevents spoilage by reacting with oxygen. It slows down development of off-flavours, odours and colour changes caused by oxidation. It protects animals against radiation and the acute toxicity of various xenobiotics and mutagens.