The policy applies to a relatively narrow category of the antibiotics, leaving ample leeway to feed chickens other drugs used in human medicine, according to the Natural Resources Defense Council, one of the environmental groups that has been pushing for broader bans on antibiotic use in poultry, beef and pork.
"This is a small step that is much less meaningful for humankind than Burger King would have you believe," said Dr. David Wallinga, the council's senior health officer. "The fast-food industry is moving away from routine antibiotic use in their chicken supply and the chains that drag their feet will continue to fall behind."
Officials from Restaurant Brands were not immediately available for comment on the policy, which would be phased in over the next two years at its Burger King restaurants in the U.S. and Tim Hortons doughnut restaurants in Canada.
The World Health Organization defines antibiotics as "critically important" when they are the sole drug available to combat a microbe that can be transmitted from nonhuman sources or that can acquire resistant genes.
The U.S. Food and Drug Administration's voluntary program to phase out antibiotic use in the nation's meat supply applies to a broader category of drugs that are "medically important" in human health. The agency issued several new guidelines this year limiting use of antibiotics to measures "considered necessary for assuring animal health" under "veterinary oversight or consultation."
In 2015, McDonald's and Subway joined Panera Bread and Chipotle Mexican Grill in implementing policies eliminating the use of antibiotics deemed medically important in human health. Yum Brands implemented a similar policy this year at its Taco Bell restaurants, but is under pressure from activists to broaden it to its KFC outlets.
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