Arby's Inc. will ban cigarette smoking in the 257 restaurants it owns and will pressure franchise owners who operate another 1,991 to do the same.
And International Dairy Queen Inc. is urging its 6,000-plus Dairy Queen, Orange Julius and Karmel Korn franchiseholders around the world to ban smoking.
The actions announced Tuesday are one of the broadest anti-smoking steps since a group of state attorneys general began pressuring the fast-food industry last year, arguing that passive exposure to smoke harms young customers and workers.
Children account for one-fourth of the fast-food market and up to 40 percent of the industry's staff is under age 18, according to the group.
Smoking will be banned this summer in the 257 Arby's restaurants.
Arby's is the first major chain to ban smoking throughout corporate-owned restaurants, although thousands of individual fast-food outlets around the nation have banned smoking, either at the franchise holder's direction or in compliance with local laws.
"It is a terrific thing to see responsible corporate leaders stepping forward doing what is clearly in the best interest of the public," Texas Attorney General Dan Morales told a news conference here after a daylong forum on secondhand smoke in fast-food restaurants.
Tobacco industry officials denounced the smoke-free policies, questioning their value to either health or business.
"We hope that other fast-food franchises will see that Arby's presents them with a competitive advantage" if they continue to allow smoking, said Thomas Lauria, a spokesman for the Tobacco Institute. "It remains to be seen if other chains want to cut themselves off from 30 percent of their customer bases."
But Arby's vice president Mark Stine countered, "All these restaurants are going to go smoke-free. It's inevitable."
The Tobacco Institute is challenging Environmental Protection Agency estimates that sparked the latest debate over smoking in restaurants and other public places. The EPA said last year that secondhand smoke kills 45,000 non-smokers a year.
That study prompted the creation of a task force by 17 attorneys general, including Florida's, to encourage fast-food restaurants to ban smoking.
At a news conference in New York on Tuesday, New York Attorney General G. Oliver Koppell called on other chains to follow Arby's' lead.
More than 2,200 of the nation's 9,000 McDonald's have banned smoking without a directive from the corporation, said McDonald's Corp. senior vice president Richard G. Starmann. "We continue to actively encourage our restaurants to go smoke-free and more are voluntarily deciding to do so every day."
Some 600 of 5,289 Burger Kings owned by franchiseholders are smoke-free, and the 707 company-owned restaurants have non-smoking sections, said Burger King spokeswoman Cori Zywotow.
Terrie Dort, executive director of the National Council of Chain Restaurants, suggested the attorneys general are interfering in an area already being addressed by the industry.
"We are very surprised and distressed they are continuing to hammer away at one segment of the industry and holding us out as the bad guys," said Ms. Dort, whose organization represents many fast-food chains.
Because the average customer spends less than 20 minutes in a fast-food restaurant, "there is no chronic exposure in fast-food restaurants," she said.