A California judge has ruled that coffee shops statewide must post warning signs informing customers that the popular morning beverage has a cancer risk, and that has caused quite a bit of controversy. Los Angeles Superior Court Judge Elihu Berle ruled in favor of the Council for Education and Research on Toxics, an organization that claims that a chemical called acrylamide used in the roasting process for coffee beans creates a cancer risk.

Starbucks and Peet’s, two prominant coffee makers, just did not offer a convincing enough rebuttal to the nonprofit’s argument, the judge ruled.

“While plaintiff offered evidence that consumption of coffee increases the risk of harm to the fetus, to infants, to children and to adults, defendants’ medical and epidemiology experts testified that they had no opinion on causation,” Berle wrote, according to the Washington Post. “Defendants failed to satisfy their burden of proving by a preponderance of evidence that consumption of coffee confers a benefit to human health.”

It could be a hugely negative ruling for the coffee industry, as the nonprofit has asked coffee companies to pay finds of up to $2,500 for every person who has been exposed to acrylamide over the last 16 years.

But many experts say the decision is flawed. While acrylamide certainly can be detected in foods that are roasted – which includes not just coffee but potatoes, bread, and other food products – they are in such tiny traces that they are not a significant risk of cancer. The World Health Organization and American Cancer Society also agree that acrylamide is not a risk, although they acknowledge more research is needed.