Starbucks and other coffee purveyors will probably have to use warning labels after a Los Angeles judge ruled that they failed to prove they should be exempt from a California law on carcinogens and toxic chemicals.

Los Angeles County Superior Court Judge Elihu M. Berle wrote in a tentative decision in April 2018 that the coffee companies did not meet their burden to prove that there was a safe level for consumers for a chemical compound created in roasting coffee.

The long-running lawsuit, first filed in 2010, concerns whether coffee drinkers should be warned about acrylamide, which is among the more than 850 confirmed or suspected carcinogens listed under California’s Proposition 65.

More than 90 coffee roasters, retailers and distributors, including Whole Foods, Kraft and Green Mountain Coffee Roasters, stand to be affected by the decision.

The law, enacted as part of the Safe Drinking Water and Toxic Enforcement Act of 1986, requires businesses with 10 or more employees to warn people of exposure to the listed substances.

Acrylamide is created when coffee is roasted and is also found in fried potatoes and burnt toast.

It has been found to increase cancer risk in rodents. Its effect on humans remains inconclusive.

Berle said scientists who testified on behalf of the coffee companies failed to prove that there was an acceptable level of acrylamide to which consumers can be exposed.

Earlier in the trial, he also ruled that the coffee companies failed to show the chemical was not a significant risk or that requiring them to include the warnings would violate the First Amendment in the US Constitution.

“While Plaintiff offered evidence that consumption of coffee increases the risk of harm to the foetus, to infants, to children and to adults, Defendants’ medical and epidemiology experts testified that they had no opinion on causation,” he wrote.

The coffee industry has contended that it is impossible to eliminate acrylamide without affecting flavour, and that the exposure is harmless to consumers.

Raphael Metzger, the attorney for the nonprofit Council for Education and Research on Toxics, the plaintiff in the case, said he hoped the judge’s decision would push the companies to agree to reduce acrylamide levels in coffee.

“I would very much prefer that, when my addiction compels me to drink coffee, I can drink acrylamide-free coffee,” he said.

“They just don’t want to change. They want to keep doing business the way they have been doing.”

Berle will issue a final decision after giving each side an opportunity to object.

The next phase of the trial will determine the civil penalties to be levied on the defendants. – Los Angeles Times/Tribune News Service