Controversy over ingredients used in popular sports drinks has erupted this week after the discovery of brominated vgetable oil’s use in over 10% of all drinks sold in the US, a chemical which bears startling similarities to flame retardants.

Brominated vegetable oil (BVO) has been found in use in a wide range of soft drinks, sports drinks and energy drinks sold within the U.S., including Gatorade, Powerade, Mountain Dew, Fanta and Fresca. The ingredient is used primarily in citrus drinks to help the flavoring stay evenly distributed and keep from separating.

Bromine, the substance that acts as the base of brominated vegetable oil, is used as a flame retardant in items like household furniture and children’s toys. High build-up of bromine in the body and breast milk has been found to cause changes in thyroid hormones and puberty at earlier ages, as well as reducing fertility and causing neurological impairments.

Side effects particular to BVO in particular  include abdominal pain, severe acne, skin rashes, fatigue, ulcers, loss of appetite and muscle coordination, while more severe reactions include cardiac arrhythmia, acute paranoia and other psychotic symptoms.

While its use has been authorized by the FDA, the substance has been a continual topic of debate within the U.S. for over three decades. As BVO is already banned in numerous countries, another, less-harmful chemical has been used to achieve the same emulsifying results without, some health food advocates have begun to wonder how the debate has been allowed to continue for so long.

Part of the reason why BVO is listed as safe by the FDA is due in part to it being used as early as the 1930s, before the current stringent regulations used by the FDA in testing food additives were added by the Food, Drug and Cosmetic Act. When that law was passed in 1938, it included an exemption in chemical testing for additives “generally recognized as safe.” According to Tom Neltner, director of the Pew Charitable Trusts’ food additives project, this loophole allows many companies to push through additives without accurate testing.

“I worked on the industrial and consumer products side of things in the past, and if you take a new chemical and put it into, say, a tennis racket, you have to notify the E.P.A. before you put it in,” Mr. Neltner said, referring to the Environmental Protection Agency. “But if you put it into food and can document it as recognized as safe by someone expert, you don’t have to tell the F.D.A.”

In 1970, BVO was taken off the list of “generally recognized as safe” additives after the Flavor and Extract Manufacturers Association removed their support of its use. The chemical additive then underwent a few rounds of testing between 1971 and 1974, without conclusive results. According to Patricia El-Hinnawy, a spokesperson for the F.D.A., an interim ruling in 1977 set the legal amount of BVO in food products to be 15 parts per million.

But, while that interim ruling was only meant to be in place until further studies could be conducted, the F.D.A’s policy regarding BVO remains unchanged after 35 years.

“Any change in the interim status of BVO would require an expenditure of F.D.A.’s limited resources, which is not a public health protection priority for the agency at this time,” Ms. El-Hinnawy wrote.

Michael F. Jacobson, co-founder and executive director of the Center for Science in the Public Interest, discovered that the longest period of testing for BVO only covered four months, despite the standard length of time for health benefits being two years. As Jacobson noted, this abbreviated research period made it impossible to verify a safe level of consuming BVO, leaving him with one conclusion: “The testing of BVO is abysmal.”