Chinese food safety authorities have been studying the potential for benzene residues to form in soft drinks containing ascorbic acid and sodium benzoate, according to local media reports.
A public statement is expected soon. Benzene is listed as a carcinogen by public health authorities.
Food safety bodies from several countries around the world have, in recent weeks, attempted to learn more about the potential for benzene formation in drinks.
Their interest was sparked after the US Food and Drug Administration revealed to BeverageDaily.com it had found some drinks in the US that contained benzene above the five parts per billion legal limit for water there.
Britain's Food Standards Agency (FSA) said it would conduct its own investigation after industry testing on 230 soft drinks found average benzene levels above the UK's one part per billion limit for drinking water.
The tests, done on products at the end of their shelf-life, found benzene levels up to eight parts per billion in some drinks. Benzene is listed as a known carcinogen.
The FSA re-iterated that levels found to date were not a public health concern.
The UK has no limit for benzene in soft drinks, and a spokesperson for the country's soft drinks association said the water limit was not applicable.
Yet, a UK food legislation expert told BeverageDaily.com any court would likely look to the drinking water limit for guidance if considering benzene in soft drinks. Water is still the main ingredient in most soft drinks.
Investigation
A BeverageDaily investigation over the last couple of months has confirmed from several industry and government sources that benzene can form in drinks when two common ingredients - sodium benzoate and ascorbic acid (vitamin C) - react.
Both the FDA and the US soft drinks industry has known this for 15 years, as testified by an internal FDA memo date January 1991. The issue was, however, never announced to the public.
The industry told the FDA it would "get the word out and reformulate", according to FDA chemist Greg Diachenko. Yet, now the issue has returned. Diachenko said authorities were still evaluating results, but "we certainly want to make sure there is some reformulation".
The safety body has come under pressure from campaign groups in recent days to release results from its recent testing on soft drinks.
It was originally alerted to the continuing presence of benzene in drinks by independent laboratory tests in New York.
Results of those tests, passed on to BeverageDaily.com, show a couple of soft drinks in the US up to two-and-a-half and four times above the 10 parts per billion legal limit for drinking water set by the World Health Organisation.
Perrier bottled water was recalled for containing lower levels of benzene in 1990.
Kevin Keane, of the American Beverage Association (ABA), assured consumers there was no health risk, but said some brands may not be aware of the potential for sodium benzoate and ascorbic acid to form benzene.
"15 years ago it was under control, but this is a fast-growing industry. There are a lot of new companies, a lot of new brands and things have changed,"
ABA scientist Mike Redman said companies had learnt to control benzene formation by adjusting levels of the two ingredients in their drinks.
But, Glen Lawrence, a scientist who helped the FDA with testing in 1990, said in an interview with BeverageDaily.com soft drinks firms should not use sodium benzoate and ascorbic acid together.
He was concerned that producers might be adding more vitamin C into drinks as to target consumer health trends.
"There is no good reason to add ascorbic acid (vitamin C) to soft drinks, and those that may have ascorbic acid naturally in them (juices) should not use sodium benzoate as a preservative. So it is really very easy to avoid the problem."
Lawrence co-authored a 1993 article in the Journal of Agricultural and Food Chemistry, detailing how benzene could form in the acidic conditions of drinks when sodium benzoate and ascorbic acid were present.
