About two-thirds of smokers will die early from cigarette-based illnesses. Cigarettes are also very addictive. Because of this, it seems reasonable to place warnings on their labels.

If a Los Angeles Superior Court judge has his way, California businesses will have to put similar warnings on something else that can be addictive, coffee. His ruling, which is being challenged by coffee producers, is harder to justify in terms of health — if it can be justified at all.

California’s Proposition 65, enacted in 1986, mandates that businesses with more than 10 employees warn consumers if their products contain one of many chemicals that the state has ruled as carcinogenic. One of these chemicals is acrylamide. Like many other substances, acrylamide causes cancer in rats — when they are pumped full of huge doses in ways that don’t approximate real life.

In humans, the data are far less clear. The American Cancer Society (which does not shrink from saying things cause cancer) reports on its website that “there are currently no cancer types for which there is clearly an increased risk related to acrylamide intake.”