"We strongly feel that it's unjustified," ICO Executive Director Jose Sette said in an interview late on Friday about the preliminary ruling by Los Angeles Superior Court Judge Elihu Berle.

The judge's March 28 ruling found that Starbucks and other companies had failed to show there was no significant risk from acrylamide, a carcinogen produced in the coffee roasting process, court documents showed. [nL1N1RB2GF]

Starbucks, the world's largest coffee shop chain, is one of more than a dozen defendants in the case. It did not immediately respond to a request for comment.

A final decision in the case is not expected for several weeks, while other phases of the trial play out.

Sette, who spoke on the sidelines of an ICO conference held last week in Mexico City, said the coffee industry was concerned that other markets could follow the lead of California, the most populous U.S. state and often seen as a trend-setter.

"It's a worry, but french fries have much more acrylamide than coffee," he said. "Are people going to stop consuming french fries and coffee because of this warning? I don't think so, but obviously we don't like it."

The California lawsuit was filed in 2010 by the Council for Education and Research on Toxics.

It calls for fines as large as $2,500 per person for every exposure to the chemical since 2002 at the defendants' shops in California. Any civil penalties, which will be decided in a later phase of the trial, could be huge in California, which has a population of nearly 40 million.

Labels warning consumers about the risk of cancer are not new in California, dating back to enactment of the Safe Drinking Water and Toxic Enforcement Act in 1986, better known as Proposition 65. Acrylamide is one of nearly 1,000 chemicals deemed by state officials to trigger a warning.

Separately, Sette said Mexican, Central America and even Colombian coffee producers currently face a growing risk from the tree-killing fungus roya, also known as coffee leaf rust.

"Roya is the big culprit right now," he said, noting that the mostly arabica-growing region had been recovering from a previous roya outbreak a few seasons ago.

(Reporting by David Alire Garcia; Editing by Dan Grebler)

By David Alire Garcia