A state judge ruled that California cannot require the nation's three largest tuna companies to place mercury warning labels on their cans.
State Attorney General Bill Lockyer sued the tuna canners two years ago to enforce Proposition 65, a 1986 state law requiring consumer warnings about reproductive toxins such as mercury, which has been linked to developmental problems in children.
With some studies showing that tuna contains potentially unsafe levels of mercury, health advocates complain that tuna companies and government agencies haven't done enough to warn consumers about the risks.
In a ruling issued late Thursday, Superior Court Judge Robert Dondero said the state's attempt to enforce the law conflicts with federal policies on tuna consumption.
The judge also found that the mercury levels in the companies' tuna were not high enough to require labels. In addition, he ruled that virtually all the mercury in canned tuna was naturally occurring, exempting them from the warning.
The defendants are Bumble Bee Seafoods LLC, the San Diego-based maker of Bumble Bee tuna; San Diego-based Tri-Union Seafoods LLC, which makes Chicken of the Sea brand tuna; and Del Monte Corp., the San Francisco maker of Starkist.
The U.S. Tuna Foundation, which represents the industry, called the ruling a victory for consumers.
"Instead of finding ways to discourage people from eating seafood, we should be busy finding ways to help everyone eat better," said David Burney, the group's executive director. "Canned tuna is so healthy and affordable that everyone can easily gain its benefits as part of a healthy diet."
Lockyer disagreed with the decision and was considering filing an objection or appeal, spokesman Tom Dresslar said Friday, noting that mercury is harmful to pregnant women and small children.
"The decision, we believe, is wrong on the law, wrong on the science and bad for consumers," Dresslar said. "When the consumers of California go into a grocery store, they have a right to be informed about the mercury that is present in canned tuna."
Lockyer's office complained about the federal government's intervention in the case. Two months before the case went to trial in October, U.S. Food and Drug Administration Commissioner Lester Crawford sent a letter to Lockyer saying that federal law pre-empts California's warning requirement.
The Aug. 12 letter, which the defendants submitted as evidence in the trial, said general warning labels could scare them away from food they should be eating.
In March, the U.S. House of Representatives passed legislation that would prevent states from requiring food warnings that go beyond federal law. Thirty-nine attorneys general, including Lockyer, have come out against the bill.
The FDA and Environmental Protection Agency encourages Americans to consume tuna and other seafood as part of a healthy diet, but advises women who are pregnant or may become pregnant, nursing mothers and young children to avoid eating tuna.
However, the federal government doesn't require tuna companies to place consumer warning labels on their products.