Consumer advocacy groups are asking Burger King, Wendy’s, Subway and Dunkin’ Donuts for commitments not to sell the genetically engineered apples and potatoes the Department of Agriculture approved for consumption last week.

The groups — Friends of the Earth, Consumers Union, Center for Food Safety, Environmental Working Group, Food Democracy Now, Food & Water Watch, Green America, GMO Inside, Healthy Child Healthy World, Organic Consumers Association, Pesticide Action Network and CREDO — sent letters to the fast food chains on Friday.

According to Friends of the Earth, McDonald’s and Gerber have said they have no plans to sell the genetically modified, or GMO, apples.

“We anticipate that other leading companies will follow suit — particularly those that market apples to children, who are most vulnerable to possible health risks,” Lisa Archer, Friends of the Earth’s food and technology program director, said in a news release.

The USDA said the genetically engineered apples, made by the Canada-based Okanagan Specialty Fruits Inc. and the potatoes from J.R. Simplot Co., based in Boise, Idaho, are as safe and nutritious as their conventional counterparts.

Okanagan’s Granny Smith and Golden Delicious apples, known as Arctic Apples, have been genetically engineered to resist browning when cut and bruised. The company has reduced the levels of enzymes that cause browning.

Simplot’s potatoes — Ranger Russet, Russet Burbank and Atlantic — known by their trade name “Innate” have been genetically engineered to reduce black spot bruising. In addition to lower levels of enzymes, the company has engineered the potatoes to produce less acrylamide by lowering the levels of an amino acid called asparagine and the levels of reducing sugars.

Food safety groups are calling the genetically engineered fruit “unnecessary.”