The Food and Drug Administration unveiled a plan today that will begin to curb the use of antibiotics in food-producing animals. The guidance aims to phase out the use of some antibiotics that are considered "medically important" for humans. Because some of these antibiotics are widely used for promoting growth in animals — rather than directly treating infections — the FDA has shown concern that they could contribute to the creation of bacteria resistant to those antibiotics, making the drugs less effective in humans.

The new FDA guidance asks pharmaceutical companies to relabel some of their antibiotics, allowing them to be used for fighting infections but not for growth purposes. The change is only voluntary though, and it's not clear how many pharmaceutical companies the FDA will be able to get on board with the plan, which may cut into their existing profits. "The FDA is leveraging the cooperation of the pharmaceutical industry to voluntarily make these changes because we believe this approach is the fastest way to achieve our goal,” FDA deputy commissioner Michael Taylor says in a statement. “Based on our outreach, we have every reason to believe that animal pharmaceutical companies will support us in this effort.”

The Natural Resources Defense Council, an environmental advocacy group, is more than skeptical. "[The FDA's policy] is a hollow gesture that does little to tackle a widely recognized threat to human health," Avinash Kar, an NRDC defense attorney, says of the guidance in a statement. The NRDC also criticizes the policy for only barring the use of antibiotics to enhance growth, without addressing the use of antibiotics to treat stress or other issues resulting from poor feedlot conditions.

"FDA has essentially followed a voluntary approach for more than 35 years, but use of these drugs to raise animals has increased," Kar says. "There’s no reason why voluntary recommendations will make a difference now, especially when FDA’s policy covers only some of the many uses of antibiotics on animals that are not sick."

We may know more about how successful the guidance is soon. The FDA has asked pharmaceutical companies to notify them of their intent to comply with the plan within the next three months. Changes won't go into immediate effect though, but will instead be phased in over the next three years. The plan may be a basic step forward, but Taylor says that the FDA sees them as significant: "Implementing this strategy is an important step forward in addressing antimicrobial resistance."