Lawyers have filed class action lawsuits against Kraft Foods in Massachusetts, Florida and reportedly California.
The actions come after the US Food and Drug Administration (FDA) said it had found batches of Kraft's Crystal Light Sunrise Classic Orange drink contaminated with benzene at more than 14 times America's legal limit for benzene in drinking water. Independent lab tests have also found a Crystal Light drink with benzene above the water limit.
Benzene is a known carcinogen.
Kraft Foods has become the latest firm to be targeted by lawyers amid renewed concerns over benzene in soft drinks, and the action increases pressure on soft drinks makers to rigorously check their products.
The Massachusetts and Florida lawsuits against Kraft also targeted several other soft drinks makers: PepsiCo, In Zone Brands, Polar Beverages, Talking Rain Beverage Company and John Doe.
The suits say Kraft, which has been in the food and beverage business since 1903, should have known about soft drinks industry and FDA testing in late 1990 that discovered two common ingredients could react in drinks to form benzene.
An internal document passed to BeverageDaily.com details how Kraft's owner in 1990, the Philip Morris group, was discussing the general formulation of Crystal Light, just days before an internal FDA memo, dated 7 December 1990, said the soft drinks association approached the agency about the problem with benzene traces in drinks.
The two ingredients found to react to form benzene in 1990 were benzoate preservatives and ascorbic acid (vitamin C).
No public announcement was ever made, and an FDA scientist told BeverageDaily.com the agency made a private deal with the industry to "get the word out and reformulate".
The scientist also informed this website in February this year that the FDA had again found some drinks containing benzene above the US water limit, which stands at five parts per billion. There is no specific limit set for soft drinks.
The FDA said on Friday it suspected the same two ingredients as the source, but re-iterated that benzene levels found so far posed no risk to consumer health.
Kraft Foods said in a statement: "Kraft learned of this situation earlier this year and stopped producing and shipping Crystal Light Sunrise Orange single serve bottles in early February."
The group said it brought in an independent expert to help with reformulation and only resumed sales of the drink once benzene formation had been minimised. The FDA said it tested the new Crystal Light formulation and found less than one part per billion benzene.
"Consumer safety is Kraft's priority. We would not allow any product on the market if we believed it posed a safety risk," the firm said.
The FDA re-opened the benzene case after receiving results from independent lab tests on drinks last autumn. It announced on Friday that five drinks, including Crystal Light, had tested for benzene above the US water limit.
However, not all drinks with benzoates and vitamin C contained benzene, and both the FDA and Mike Redman, a scientist with the American Beverage Association (ABA), have told BeverageDaily.com that heat is a major factor.
The ABA said it was handing out new guidance to help beverage firms minimise benzene formation in drinks.
However, Glen Lawrence, a scientist who helped the FDA work out the link between benzene and the benzoate/vitamin C combination in 1990, said one of these ingredients should simply be dropped from drinks.
Erythorbic acid and citric acid are also thought to play a similar role to ascorbic acid.
See our related news section for more on BeverageDaily.com's coverage of benzene in soft drinks.