Brominated vegetable oil (BVO) is a complex mixture of plant-derived triglycerides that have been reacted to contain atoms of the element bromine bonded to the molecules. It is used primarily to help emulsify citrus-flavored soft drinks, preventing them from separating during distribution. BVO has been used by the soft drink industry since 1931, generally at a level of about 8 ppm. When used, BVO must be listed as an ingredient on the label. Alternative food additives used for the same purpose include sucrose acetate isobutyrate (SAIB, E444) and glycerol ester of wood rosin (ester gum, E445) .

BVO has been linked to numerous health hazards, including harm to the nervous system. BVO can build up in the body, and research has shown a connection between drinking large amounts of BVO-containing sodas over a long period and problems such as headaches, irritation of the skin and mucous membranes, fatigue, and loss of muscle coordination and memory. The risks of BVO have been known for decades, and some U.S. states are considering banning the use of BVO in foods because it acts as an endocrine disrupter, especially affecting the thyroid hormone and may also harm the reproductive system.