Butylated hydroxyanisole (bha)

Antioxidant: Cereals, chewing gum, potato chips, vegetable oil.
BHA retards rancidity in fats, oils, and oil-containing foods. While some studies indicate it is safe, other studies demonstrate that it causes cancer in rats, mice, and hamsters. Those cancers are controversial because they occur in the forestomach, an organ that humans do not have. However, a chemical that causes cancer in at least one organ in three different species indicates that it might be carcinogenic in humans. That is why the U.S. Department of Health and Human Services considers BHA to be "reasonably anticipated to be a human carcinogen." Nevertheless, the Food and Drug Administration still permits BHA to be used in foods. This synthetic chemical can be replaced by safer chemicals (e.g., vitamin E), safer processes (e.g., packing foods under nitrogen instead of air), or can simply be left out (many brands of oily foods, such as potato chips, don't use any antioxidant).