A Los Angeles judge has ruled that California law requires coffee companies to carry a cancer warning label.
Superior Court Judge Elihu Berle said in a proposed decision that Starbucks and other coffee companies failed to show the threat from a chemical compound produced in the coffee roasting process was insignificant.
A non-profit group had sued coffee roasters, distributors and retailers under a state law that requires warnings on a wide range of chemicals that can cause cancer.
One is acrylamide, a carcinogen present in coffee.
The coffee industry had claimed the chemical was present at harmless levels and should be exempt from the law because it results naturally from the cooking process to make the beans flavoursome.
Proposed California judicial decisions can be reversed but are reversed rarely.