The two largest soft drink producers in the world, Coca-Cola and PepsiCo, will change their recipe in the US to avoid putting a cancer warning label on the bottles.

The step comes in response to a new piece of legislation stipulating that drinks containing a certain level of carcinogens should bear a cancer warning label, the BBC reported.

The new recipe for caramel coloring in the drinks has less 4-methylimidazole - a chemical which California has added to its list of carcinogens.

The chemical has been linked to cancer in mice and rats, according to one study, but there is no evidence that it poses a health risk to humans, said the American Beverage Association, as cited by the BBC.

"While we believe that there is no public health risk that justifies any such change, we did ask our caramel suppliers to take this step so that our products would not be subject to the requirement of a scientifically unfounded warning," Coca-Cola representative Diana Garza-Ciarlante said in an email.

Both companies have assured that consumers have no reason for any health concerns and that the altered recipes will not affect the quality of the drinks or cause production problems.

Coca-Cola and PepsiCo account for nearly 90% of the soda market, according to industry tracker Beverage Digest.