The Food and Drug Administration has played down rising concern over the presence of benzene in soft drinks.

In a letter to the Environmental Working Group last week, the FDA has reiterated that it does not consider the presence of benzene at low parts per billion (ppb) an imminent health hazard. The letter appeared on the FDA Website on Tuesday (28 March).

In November last year, the FDA said, private laboratory results indicated low levels of benzene in a small number of soft drinks that contain benzoate preservatives and ascorbic acid, more commonly known as vitamin C. The FDA followed this up with research of its own into these products. "Based on currently available results from this limited survey," the FDA said in the letter, "the vast majority of beverages sampled … contain either no detectable benzene or levels below the 5 ppb limit for drinking water, and do not suggest a safety concern."

"FDA is continuing to sample beverages to gain more representative data on the current situation," the letter continues. "We intend to release our results when we have a more complete understanding of the current marketplace. Although the results to date are preliminary, they do not suggest a safety concern.

"Additionally, the agency has been in contact with manufacturers and industry trade associations. They have informed FDA that they are actively assessing whether their products contain benzene and will take appropriate steps to minimise benzene formation in their products, if elevated levels are found."

The Environmental Working Group wrote to the FDA in February, asking the FDA to issue a warning to the public about the risk of benzene in soft drinks. The organisation also called on the FDA to release the results of its tests for the presence of benzene in soft drinks.