If a lawsuit currently being evaluated by a California court goes a certain way, coffee shops and coffee-selling gas stations may be forced post labels about potential cancer-causing chemicals. They may even have to pay fines if they don't warn customers about the risks of chemicals in coffee.
The Council for Education and Research on Toxics — the group behind the lawsuit — wants to penalize companies that don't warn customers that coffee contains acrylamide, a chemical that California lists as one "known to cause cancer."
Acrylamide naturally forms when plants and grains are cooked at high temperatures. It's created in the process known as the maillard reaction, in which high heat transforms sugars and amino acids in ways that change flavor and tend to brown food. When potatoes, bread, biscuits, or coffee are heated, acrylamide forms.
But there's no conclusive reason to believe that coffee or other foods expose humans to dangerous levels of acrylamide. And there's no known way to make coffee without acrylamide.
http://www.businessinsider.com/how-coffee-drinking-affects-cancer-risk-acrylamide-2018-1