Flame Retardant in Your Mountain Dew? Yep

There's flame retardant in your Mountain Dew. That soda with the lime-green hue (and other citrus-flavored bubbly pops) won't keep your insides fireproof, but it does contain brominated vegetable oil, a patented flame retardant for plastics that has been banned in foods throughout Europe and in Japan.

Brominated vegetable oil, or BVO, which acts as an emulsifier in citrus-flavored soda drinks, is found in about 10 percent of sodas sold in the U.S.

"After a few extreme soda binges - not too far from what many [video] gamers regularly consume - a few patients have needed medical attention for skin lesions, memory loss and nerve disorders, all symptoms of overexposure to bromine," according to a recent article in Environmental News.

PepsiCo., owner of Mountain Dew, declined to comment on the brand-specific issue.

But most safety studies that have been done on animals use very high doses of BVO, up to 200 times the amount allowed in U.S. soft drinks. As the old saying in toxicology goes: The dose makes the poison, said Dr. John Spangler, professor of family and community medicine at Wake Forest Baptist Medical Center. Even drinking too much water too quickly would cause water-intoxication, he said.

The  Food and Drug Administration limits the use of BVO to 15 parts per million in fruit-flavored beverages.

"Brominated vegetable oil  is considered safe by FDA for use as a flavoring adjuvant in fruit-flavored beverages based on a large margin of safety between the expected human exposure from its use and the highest no-observed-adverse effect levels from several long-term animal studies that were conducted on this substance," an FDA spokesperson said in an email to ABCNews.com.

"The 15 ppm (parts per million) dose was set well under the no observed effect level," said Spangler.

"Having said that, BVO accumulates in the heart, liver and fat tissue,"  Spangler said. "New studies are warranted to update the old studies, especially given that the patterns of soft drink consumption have changed so dramatically over the past three decades."

U.S. consumers have a long history of wanting their food to look a certain way, said LuAnn White, director at the Center for Applied Environmental Health at Tulane University.  And so additional dyes, chemicals and preservatives are used in our food to maintain a certain look.

"The marketing of many foods have conditioned many people to expect a certain look in foods that are not necessarily the color the foods really are," said White. "Some food additives are useful for preserving food quality, but many colorings do not necessarily serve any useful purpose beyond marketing and appearance."

Despite the unsettling-sounding ingredients, experts agreed that the biggest killer is the excessive sugar and calories found in most sodas.

"In contrast, diabetes and overweight are also very bad diseases, and unfortunately, far more common, and they cause far more deaths than bromism ever did," said Dr. Marcel Casavant, chief of pharmacology and toxicology at Nationwide Children's Hospital in Ohio. "For this reason alone, the dose of sweeteners in these products is more dangerous than the dose of bromine."

A 20-ounce bottle of Mountain Dew contains 290 calories, 77 grams of sugar and 91 milligrams of caffeine.

"None of us should be adding too much sugar to our diets; even small doses might be 'too much' for some diabetics and some overweight people, while most of us can tolerate a bit more," said Casavant.

While it is easier to call attention to a chemical, the more dangerous issue is the high calorie count of the sodas, said White.  The example of the video gamers should call attention to the sedentary lifestyle now so prevalent in the U.S.,  White added.

"Obesity is the underlying cause of much of the chronic disease that plagues the U.S. population," White said. "This is by far the greater health risk.  Anyone consuming six sodas at a sitting gets an awful lot of nonnutritional calories, and gamers or others who do not have a high level of exercise will gain weight over time."