At a glance, warning people about substances that can cause cancer seems like a sensible way to protect the public health. California's Proposition 65 requires companies to inform their employees and consumers if their products expose them to "chemicals that cause cancer, birth defects or other reproductive harm." But as so many regulations do, the 1986 ballot initiative wound up leading to some really stupid labeling requirements and predatory lawsuits. The latest example is a ruling by Los Angeles County Superior Court Judge Elihu M. Berle requiring coffee roasters in the state to label their products as potentially carcinogenic due to the presence of a naturally occurring chemical called acrylamide.
Acrylamide forms upon heating in many foods, particularly starchy ones like french fries and potato chips, but also coffee, chocolate, certain breads, certain teas, black olives, and prunes. It won't hurt you, because humans seldom consume any carcinogenic foodstuff in the massive quantities that induce cancer activity in rats.
I repeat, you should not be worried about coffee cancer, no matter what California requires Starbucks to print on your cup. As The Washington Post reports, rodents can develop cancer from acrylamide, but only when fed "rates 1,000 to 10,000 times higher than what humans consume in food." And coffee is not even the chief culprit! That would be potato chips, in which "the highest acrylamide concentrations were measured in thousands of parts per billion, much lower than the levels that cause cancer in lab animals."
There are other chemicals on California's Prop. 65 list that you probably shouldn't worry too much about. Pyridine was added in 2002, yet the U.K. Health Protection Agency reported in 2010 that there is no evidence it causes cancer in humans, and In the Pipeline's Derek Lowe was unable to find any evidence supporting its toxicity as recently as 2017. The Prop. 65 list also contains, uh, "wood dust." What does that mean, exactly? Where do you affix the label—to the offramp sign at the state visitor center?
You should worry if you're a California business, because Prop. 65 lawsuits tend to look a lot like shakedowns. The Starbucks lawsuit closely resembles a 2002 suit filed against McDonald's and Burger King. After six years, McDonald's and Burger King settled, agreeing to warn consumers about acrylamide in their french fries, as well as to pay civil penalties to the group that brought the suit. And attorney's fees. Lots of attorney's fees.
Both suits were brought by the Council for Education and Research on Toxics (CERT), which is organized as a nonprofit. Except I can't find any information about CERT on Charity Navigator or Guidestar. According to attorney Nathan Schachtman, the nonprofit at one time shared an address and contact information with the Metzger Law Group, the law firm that filed both the McDonald's suit and the more recent Starbucks suit. In other words, one could be forgiven for suspecting that CERT was set up by trial attorneys in order to create a plaintiff that could bring Prop. 65 lawsuits against California companies.
"Californians are so inured to Proposition 65 warnings that the ubiquitous signage has become meaningless," former Burger King CEO Jeffrey Campbell wrote in 2016. "The rate of cancer in the state is no different than any other, suggesting that the warnings have no impact. In 2015 alone, companies paid more than $26 million in Proposition 65 settlements and suits. But the trial lawyers are the real winners. They take home about 70 percent of all money paid by businesses."
Google "prop 65 lawsuit" for a glimpse of a gross ecosystem of legal eagles who specialize in suing business owners who presumably haven't spent enough money on compliance officers. Wells Fargo even offers Prop 65 insurance, and helpfully notes in its brochure that "[i]ndividual plaintiff awards are one-fourth of the civil penalty paid by the defendant"—meaning the rest goes to the suing law firm.
All that said, your odds of getting cancer from something are remarkably good. The average U.S. male has a 39 percent chance of developing some type of cancer at some point in his life, and the average U.S. female has a 37 percent chance. But you probably won't get it from coffee, or the aspartame you sweeten it with.