Butylated hydroxyanisole (BHA) is white or slightly yellow, waxy solid. The primary use for BHA is as an antioxidant and preservative in food, food packaging, animal feed, and cosmetics, and rubber and petroleum products as well. BHA is particularly useful in protecting the flavors and color of essential oils and is considered the most effective of all food-approved antioxidants for this application.

However, BHA was classified as “reasonably anticipated to be a human carcinogen” by the National Toxicology Program, in their 14th report on Carcinogens, based on sufficient evidence of carcinogenicity from studies in experimental animals. Exposure to BHA caused benign and malignant tumors of the forestomach (papilloma and squamous-cell carcinoma) in rats of both sexes and in male mice and hamsters.