The addition of bromine increases the density of the oil, and the amount of bromine is carefully controlled to achieve a density that is the same as the water in the drink. As a result, the BVO remains suspended in the water instead of forming separate layers.
Long after consumption of BVO in test animals, traces remain in the body fat. Bromine is a halogen and displaces iodine, which may depress thyroid function. Evidence for this has been extrapolated from pre-1975 cases where bromine-containing sedatives resulted in emergency room visits and incorrect diagnoses of psychosis and brain damage due to side effects such as depression, memory loss, hallucinations, violent tendencies, seizures, cerebral atrophy, acute irritability, tremors, ataxia, confusion, loss of peripheral vision, slurred speech, stupor, tendon reflex changes, photophobia due to enlarged pupils, and extensor plantar responses. In one case, a man who drank eight liters of Ruby Red Squirt daily had a reaction that caused his skin color to turn red and produced lesions diagnosed as bromoderma. The excessive quantities together with the fact that the man had a higher than normal sensitivity to bromine, made this an unusual case. A similar case reported that a man who consumed two to four liters of a cola containing BVO on a daily basis experienced memory loss, tremors, fatigue, loss of muscle coordination, headache, ptosis of the right eyelid as well as elevated serum chloride. In the two months it took to correctly diagnose the problem the patient also lost the ability to walk. Luckily bromism was finally diagnosed and hemodialysis was prescribed which resulted in a reversal of the disorder. A Pepsi product website notes that BVO has been used by the soft drink industry since 1931.
In test animals, BVO consumption has caused damage to the heart and kidneys in addition to increasing fat deposits in these organs. In extreme cases BVO has caused testicular damage, stunted growth and produced lethargy and fatigue.