California is suing three major canned tuna companies for not warning customers about the potential exposure to mercury from eating tuna.

Del Monte Foods, which makes StarKist tuna, Bumble Bee Seafoods, which makes Bumble Bee tuna, and Tri-Union Seafoods, which makes Chicken of the Sea tuna, were named as defendants in the case, which was filed at San Francisco Superior Court, reported Reuters.

The lawsuit alleges that the three companies violated Proposition 65, which requires companies to provide warnings about potential exposure to known carcinogens and reproductive toxins.

"Prenatal exposure to mercury can cause serious disabilities in infants and children," he said. "We're not trying to eliminate tuna from people's diets. We're trying to enforce the law and protect the health of California women and children," state Attorney General Bill Lockyer was quoted by Reuters as saying.

Lockyer said methylmercury compounds have been listed under Proposition 65 as carcinogens since 1996, while methylmercury has been listed as a reproductive toxin since 1987. Mercury and mercury compounds have been listed as reproductive toxins since 1990.

In response, the US Tuna Foundation (USTF) said that the industry "strongly disagrees" with the Attorney General and is prepared to demonstrate in court that the industry is in full compliance with Proposition 65 provisions.

"We believe that Californians have nothing to gain and much to lose by the Attorney General's action. Tuna is a safe and healthy food," said David Burney, USTF executive director.

"This suit is not grounded in science and will needlessly scare consumers away from affordable foods that are good for them," he added.

"According to industry representatives, canned tuna is in full compliance with Proposition 65 provisions. In fact, a key distinction in this case will be that Proposition 65 does not apply to those substances, which are derived from natural sources, such as mercury in fish," the USTF said.