WASHINGTON — Chobani is the target of a petition from a national coalition that is challenging the Greek yogurt brand on its main ingredient.

G.M.O. Inside, an organization led by environmental group Green America, wants New York-based Chobani to stop marketing its products as “healthy” and “natural” until it switches to verified non-bioengineered milk sources. Currently, the company uses milk from cows likely fed bioengineered grain or ingredients, according to the group.

“Demand for non-G.M.O. foods is growing every day, but for even the most careful consumer it can be very difficult to know which products are affected by G.M.O.s,” said Elizabeth O'Connell, campaign director for G.M.O. Inside.
“Chobani has an opportunity to be a leader amongst meat and dairy companies by listening to its customers and ensuring its cows are given non-G.M.O. food.”

A Chobani spokesperson said the company doesn’t claim its products are bioengineered-free.

“Our team is dedicated to addressing G.M.O.s and is currently navigating its complexities, specific to dairy,” said Lindsay Kos, communications manager for Chobani. “As it stands now, we do not claim to be G.M.O.-free. According to some, doing so would require us to ensure the feed to 78,000+ cows, across 875+ farms is 100% G.M.O.-free. It requires teamwork among our employees, farmers, and industry partners.”

The U.S. Department of Agriculture recently approved use of a label for meat and liquid egg products with the claim the products came from animals raised on diets containing no bioengineered grain or ingredients. The approval was in response to an application from the Non-G.M.O. Project and three food companies and was thought to encourage other meat, poultry and egg producers to seek to qualify for using the label to distinguish their products in the marketplace and among consumers who seek foods that are free from bioengineered ingredients. However, approval of the label did not imply a change in the view of the U.S.D.A. and the U.S. Food and Drug Administration that approved bioengineered crops and feedstuffs are safe to consume and do not significantly differ from crops developed through more traditional plant-breeding technologies.