Coffee sold in California must carry a cancer warning, a court has ruled.
The Los Angeles judge said that Starbucks and about 90 other coffee sellers had failed to warn customers of a potentially toxic compound being produced during roasting
The companies were owned by a California-based non-profit Group sued for chemical acrylamide.
The group argued that acrylamide is considered to be carcinogenic under state law and should therefore be sold with a warning] Judge Elihu Berle, judge in the Supreme Court, ruled that companies should not be exempted from the law because they do not demonstrated that "the consumption of coffee brings benefits to human health".
Companies appeal against decision by April 1
How much risk is there for acrylamide
Acrylamide is formed when starchy foods are roasted, grilled or roasted fo r long periods of high temperature.
Studies in animals revealed that the chemical causes tumors. This indicates that it can also be carcinogenic in humans.
Scientists believe that there should be an exposure margin of 10,000 or more between an average intake of acrylamide by an adult and the lowest dose that could have adverse effects]. But right now, the numbers are 425 for the average adult and 50 for the average adult the most consumptive toddlers, making it a slight public health problem, say British and European food safety experts.
A statement from the National Coffee Association (NCA)
"Cancer warning signs on coffee are misleading, and the US government's own dietary guidelines say coffee can be part of a healthy lifestyle," the statement said.
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- Q & A: Acrylamide
The lawsuit was filed in 2010, stating that coffee sellers should pay fines of up to $ 2,500 (£ 1,800) for each person since 2002 Acrylamide was exposed in California.  The next phase of the process will set the exact penalties, but some companies have reportedly agreed to settle and publish warnings about the chemical.
The decision came despite a recent easing of concern over the possible health effects of coffee was removed from a list of possible carcinogens in 2016 by the United Nations World Health Organization.
Last year, a study of nearly half a million people from 10 European countries found that drinking three cups of coffee a day could bring health benefits.  But skeptical experts said it was impossible to say that the coffee had a protective effect.