Evans originally was planning to target only baby foods. But later Thursday, her staff announced that her bill has been broadened to require GMO labeling for all foods used for "human consumption" in California. That more closely mirrors Proposition 37, which voters rejected in 2012. The senator's staff said about 85 percent of all foods on store shelves in California contain genetically modified organisms.
Evans did not respond to a request seeking comment on the changes made to the proposed legislation. Teala Schaff, her spokeswoman, said the changes were made at the request of the California State Grange, which pushed for the original bill.
"It's still a consumer-choice bill. She's always been a strong consumer-choice advocate," Schaff said.
Mike Greene, director of legislative affairs for the California State Grange, on Thursday attributed the last-minute changes to a "lack of communication between us and the senator's office."
The grange has about 10,000 members in about 45 California counties. Greene said the organization passed a resolution at its annual meeting in October calling for GMO labeling on baby foods. He said in November, a coalition of 17 groups, including the Grange, Pesticide Action Network and Organic Consumers Association, amended that stance to call for such labeling on all foods sold for human consumption in California.
He said the group had four meetings with the senator's staff but that "they didn't understand we were no longer talking about baby foods. We were talking about all foods."
That raises the stakes on the proposed legislation considerably. Anti-GMO advocates have been pushing for such labels for years, even though the federal government and many scientists say the biotechnology behind genetically modified organisms is safe.
Most grocers are opposed, on the grounds that such labels are unnecessary, confusing to consumers and likely to increase costs to produce new labels or ingredients to meet California's new restrictions.
"Every credible U.S. and international food safety authority that has studied GMO crops has found that they are safe and that there are no health effects associated with their use," said Brian Kennedy, a spokesman for the Grocery Manufacturers Association.
He said the nation's food safety and labeling laws "should not be set by political campaigns, or state and local legislatures."
Humans have been altering the foods they consume for millennia. The current debate centers on genetically modified plants that are engineered to resist insecticides and herbicides, add nutritional benefits or improve crop yields and increase the global food supply. Most corn, soybean and cotton crops grown in the United States today have been genetically modified.
The Food and Drug Administration does not require genetically modified foods to carry a label, and attempts to change that at the federal level have failed. No states currently require labeling of GMO foods, although Greene said bills are pending in 26 states.
In 2005, Sonoma County voters rejected a ballot measure that would have banned certain GMO products for 10 years, ostensibly to allow more time for testing.
All of that has not deterred organic food companies and some consumer groups from continuing their push for labeling. Whole Foods Market is requiring all products sold in its stores in the U.S. and Canada to carry labels indicating whether they contain genetically modified ingredients by 2018.
Karen Hudson, coordinator of the group Sonoma County Label GMOs, said people "really don't know what the repercussions" of serving foods with genetically engineered ingredients are. With respect to infants, she said it's important parents be given the choice of knowing what goes into the products.