The federal government and a watchdog organization are sparring over how difficult it is to keep cancer-causing benzene out of soft drinks.
Benzene, which has been identified as a carcinogen by the World Health Organization, occurs when two common soft drink preservatives—sodium benzoate and ascorbic acid (vitamin C)—are combined. But according to the U.S. Food and Drug Administration, other factors, such as exposure to light and elevated temperatures, may affect how benzene is made and in what quantities.
"We're trying to pin down the conditions when benzene will form," said an FDA spokesperson. "We know it takes more than just having those two ingredients."
The FDA began a benzene study last December and has so far tested 60 to 70 soft drinks, the spokesperson said. The FDA source added that the study, which is expected to be complete by the end of this year, will likely have different results than the FDA's Total Diet Study, which showed that 79 percent of diet soda samples tested between 1995 and 2001 had benzene levels above the federal limit for benzene in tap water.
"Our suspicion right now is that [the Total Diet Study] is not as reliable as the study we have now" because the earlier study tested for many different soft drink contaminants, including metals and pesticides, which could conceivably skew the results, the FDA source said. The current study tests exclusively for benzene.
Activists at the Washington, D.C.-based Environmental Working Group are perplexed at the reasons for this latest study. Even though specific conditions may be necessary for benzene to form, no such reaction occurs if the two ingredients are eliminated, according to an EWG scientist.
"It doesn't really make sense to do more research when you know exactly how to stop the problem—not putting the two ingredients together in the first place," said Tim Kropp, senior scientist at EWG. "You have an easy answer of how to get rid of a carcinogen in a drink."
EWG Senior Vice President Richard Wiles charged in an April letter that the FDA has known about benzene in soft drinks since 1990, but has "suppressed the information from the public and asked soft drink manufacturers to voluntarily solve the problem." Robert Brackett, director of the FDA Center for Food Safety and Applied Nutrition, responded in a letter that an FDA study was published in 1993 that showed "that benzene was detected only at insignificant levels." He didn't mention the Total Diet Study.
Kropp said EWG plans to file a Freedom of Information Act requesting copies of all tests the government has done on benzene. EWG might also commission its own benzene studies, he said.
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