By Bog Egelko

Makers of whole-grain cereals like Cheerios and Grape-Nuts Flakes won’t have to tell California consumers that their products contain a chemical that may cause cancer.

But the issue of warning labels is still unsettled for other food products that contain both healthy ingredients and possible carcinogens.

The state Supreme Court last week denied review of a suit that sought to require cereal makers Post, General Mills and Kellogg to add warnings to their labels under Proposition 65, the 1986 ballot measure that requires businesses to notify the public when their products contain ingredients that have been shown to cause cancer or birth defects.

At the same time, however, the court granted requests by health and environmental groups to limit the scope of an appellate ruling by removing the case as a precedent that could be cited by other food manufacturers as a reason not to have Prop. 65 warning labels.

The cereals contain acrylamide, a chemical that has been identified as a potential cause of cancer by both federal and state agencies. It has long been used in manufacturing, and in 2002, researchers detected its presence as a byproduct of baking, roasting or frying carbohydrate-rich foods such as potato chips and French fries, both of which now carry Prop. 65 warning labels.

But in response to a suit seeking the same labels for whole-grain cereals with acrylamide, the Second District Court of Appeal in Los Angeles agreed with federal health officials who said that such warnings would cause more harm than good.

Requiring warnings on all foods containing acrylamide at levels that pose any risk of cancer “would cause many otherwise healthful foods to appear to consumers to be unhealthful,” the court said in a 3-0 ruling in July. It said those foods include peanut butter, rye and whole wheat bread, sunflower seeds and prune juice.

The court cited another ruling that refused to require Prop. 65 warnings on canned tuna that may contain harmful levels of mercury. The appeals court in that case said federal health officials were already advising consumers of tuna’s benefits and possible risks, superseding the state law.

The state Supreme Court, by leaving the ruling intact but removing it as a legal precedent, has left for future cases the question of whether the healthful aspects of other food products outweigh the need for Prop. 65 warnings. That relieved attorney Joseph Mann, who filed arguments on behalf of the Center for Environmental Health, the Center for Food Safety and other groups asking the court to limit the scope of the ruling.

The fact that a cookie product might be made with whole grains, Mann contended, “doesn’t mean you can jack it up with sugar and call it a health food, and say states can’t regulate that.”

The case is Post Foods vs. Superior Court (Sowinski), No.S250937.