The UK's Co-op retail chain has withdrawn its Low Calorie Bitter Lemon drink, after tests by the Foods Standards Agency (FSA) found one product contained benzene 28 parts per billion, well above the country's strict one part per billion limit for drinking water.
The FSA has also demanded recalls on supermarket Morrison's no added sugar pineapple as well as Popstar sugar free lemon & lime and Hyberry high juice no added sugar blackcurrant squash.
These contained 11, 17 and 12 parts per billion respectively of benzene, a known carcinogen.
The news comes one month after the US Food and Drug Administration first revealed to BeverageDaily.com it had found some drinks containing benzene above the legal limit for water in the US.
Both it and the FSA have said they believe the benzene was formed through a reaction between two common ingredients - sodium benzoate and ascorbic acid (vitamin C) - in the drinks.
A BeverageDaily.com investigation earlier this year confirmed that both the FDA and the American soft drinks association have known about this problem for 15 years.
No public announcement was ever made, and the re-emergence of the problem suggests a communication breakdown.
Andrew Wadge, director of food safety at the UK's FSA, sought to assure consumers Friday that benzene levels found so far in drinks constituted little health risk. He said people got much more benzene from the air they breathed every day.
The FSA said it did not detect benzene in 107 out of 150 soft drinks tested, and a further 38 samples contained benzene between one and 10 parts per billion.
The watchdog, however, said in a statement it wanted more action from the industry.
"These results show that it is technologically possible to produce soft drinks without detectable traces of benzene. This is what we want all manufacturers to do."
The agency's test results differed from samples of 230 soft drinks taken by the UK soft drinks association three weeks ago. The highest benzene level it found was eight parts per billion.
An FSA spokesperson said it was using the World Health Organisation's 10 parts per billion limit for benzene in drinking water as a benchmark. There is no specific limit for benzene in soft drinks.
A spokesperson for the UK's Co-op retailer said the group was working with suppliers to reduce or remove the potential for benzene to form in its drinks. The soft drinks association, meanwhile, re-iterated on Friday that benzene levels found were low and that drinks were safe.
The FSA now plans to carry out more tests on drinks containing sodium benzoate and ascorbic acid by exposing them to heat and light.
"Heat is a major factor," according to Mike Redman, an American Beverage Association scientist who also represented the industry in meetings with the FDA on benzene back in 1990/1991.
He said benzene formation could be best controlled by adjusting levels of sodium benzoate and ascorbic acid in the drinks. Industry testing in 1990, led by Cadbury Schweppes, also found the additive EDTA could block benzene formation.
Diet and sugar-free drinks are considered more at risk because sugar has also been found to help block the reaction.