Chipotle Mexican Grill announced it has begun labeling all the ingredients the chain uses that contain genetically modified organisms. It becomes the first U.S. restaurant chain to include such labels.

Chipotle begins labeling GMO burritos Chipotle joins Whole Foods Markets and Ben and Jerry’s as major U.S. brands that shun GMOs. Whole Foods became the first U.S. food retailer to label GMO ingredients, and Ben and Jerry’s said the company will replace all GMO derived components in its ice cream.

Chipotle, however, says going GMO-free will be difficult. The chain is working to reduce the GMO content of its ingredients but doesn’t expect to achieve a 100 percent GMO-free menu, given what it describes as the nature of the U.S. food industry.

Chipotle posted a list on its web site that identifies which ingredients contain GMOs. Twelve of the 24 ingredients are labeled with a red “G,” and that includes chicken, pork, rice and tortillas. The meat products qualify for the red G because they are cooked with soy oil. Chipotle advertises its meat products as “responsibly raised” without hormones or antibiotics.

The Chipotle website states that the restaurant plans to move away from using any genetically modified ingredients in the future and “recently switched our fryers from soybean oil to sunflower oil” because commercial sunflower oil is GMO-free.