High amounts of bromine can also cause skin breakouts known as halogen acne.
What about lower levels?
It’s not known whether BVO might pose health concerns at the low levels most people take in, Vetter says.
But he and others think the food additive needs further study.
That’s because it’s in the same chemical family as flame-retardants like polybrominated diphenyl ether (PBDE).
Scientists are studying brominated flame retardants because blood tests show that these chemicals can build up in our bodies. Early studies suggest that flame-retardant chemicals disrupt normal hormone function, leading to problems with brain development in children, fertility, thyroid function, and possibly cancer.
In a 2012 study, Vetter found that in the U.S., BVO intake dwarfs the level of our exposure to other similar chemicals. Adults take in 4,000 times more BVO than PBDEs on average, for example, while kids get about 1,000 times more.
Is BVO FDA-approved?
In 1958, the FDA said BVO was generally safe to use, but it changed its mind in the 1970s, giving BVO "interim" status. Interim status means beverage manufacturers can use it in limited amounts pending the outcome of further studies. Those studies have never been done, leaving the ingredient in limbo for more than 30 years.
It’s allowed to be used at a level not to exceed 15 parts per million.
“It’s used in much lower amounts, about 8 parts per million,” Shelke says, “However, this rule was made at a time when sodas were a treat, in the 1950s, and not part of the daily diet.”
“So the rules were absolutely relevant then,” she says. “But today, the way consumers drink sodas today is very different.” And she thinks the rules may need to be revisited.
Other countries are playing it safer. BVO is banned as a food additive in Japan, India, and the European Union.
What products contain BVO?
BVO is in some citrus soft drinks including Mountain Dew, Squirt, Fresca, and Fanta. It’s also in sports drinks like Powerade and some pre-mixed cocktails.