A judge in California has ruled that coffee retailers, including the ever-popular Starbucks, must carry a cancer warning label for their products. Why? Because of a chemical that is produced in the roasting process.

Elihu Berle, a Los Angeles Superior Court Judge, wrote in his decision on Wednesday that coffee companies have failed to show that a carcinogen produced in the roasting process posed no significant threat. “Defendants failed to satisfy their burden of proving by a preponderance of evidence that consumption of coffee confers a benefit to human health,” he wrote.

The coffee industry obviously isn’t happy with the decision, and had claimed the acrylamide chemical that was present only exists at harmless levels. Their argument is that coffee retailers should be exempt from the law because it occurs naturally in the cooking process, which is necessary to make the beans flavurful.

Starbucks and the other involved defendants now have until April 10 to appeal the ruling.

The lawsuit against some 90 coffee retailers was filed in 2010 by the Council for for Education and Research on Toxics.

In a statement responding to the ruling, the National Coffee Association said the industry is considering all options, including appeals and further legal action. The group’s President and CEO William Murray said, “Coffee has been shown, over and over again, to be a healthy beverage. This lawsuit has… confused consumers, and does nothing to improve public health.”

Didn’t see this coming, but we’ll all have to wait and see how this one plays out.