After years of scientific and political stalemate, the Codex Alimentarius Commission, a UN food standards-setting body, narrowly voted to advance a residue limit for ractopamine hydrochloride, a controversial veterinary drug used in food animal production.

The 69-67 vote to adopt a Maximum Residue Limit (MRL) for the beta agonist — which is approved for boosting growth and increasing leanness in pigs, cattle and turkeys — is a big win for the United States’, Brazil’s and Canada’s trade interests.

Major meat exporting countries that use ractopamine have been pushing for a global standard for several years. A Codex MRL makes it easier for the U.S. and others to challenge countries like China, the European Union and Taiwan for having zero tolerance policies for ractopamine residues in meat products. With an MRL in place, the World Trade Organization is much more likely to rule against any country that has a more restrictive policy.

The Codex MRL is 10 parts per billion (ppb) for muscle cuts of beef and pork. The U.S. Food and Drug Administration’s limit is 30 ppb for beef and 50 ppb for pork.

Such a close and contentious vote is rare at Codex. The scientific commission adopts dozens of food safety standards each year by consensus, with well over one hundred countries participating.

Ractopamine MRLs have been stuck at Step 8, the final step before adoption, since 2008. Interests on all sides of the ractopamine issue have worried that the bitter fight over the drug could ultimately jeopardize the legitimacy of Codex.

“We are concerned that with this vote, Codex is becoming another politicized global body, rather than the science-based consensus body it has managed to be so far,” said Michael Hansen of Consumers International, which represents 220 consumer organizations in 110 countries. CI has observer status at Codex meetings, meaning they cannot vote but may have a representative present.

“In the past, Codex has avoided adopting standards where scientists disagree, or where the scientific data is lacking or insufficient,” added Hansen, in a CI statement. “We now see a situation where trade concerns are trumping science. This does not bode well for the credibility of Codex standards in the future.”

U.S. officials and agriculture interests take a different view. They praised the vote in favor of MRLs as evidence that the commission is still science-based and ultimately not swayed by politics.

“It is paramount that science is the foundation for all decisions made in the international community. Today, the Codex commission proved they are willing to trust science and make decisions based on facts rather than politics,” said Kathy Simmons, chief veterinarian for the National Cattlemen’s Beef Association in a press release. “We are very pleased that we can move ahead on adopting international standards for ractopamine.”

Part of the reason the issue is so controversial is that the EU and China together produce and consume the vast majority of the world’s pork. Both have repeatedly sought to block ractopamine MRLs because they prohibit their own producers from using the growth-promoter and don’t want to accept imported meat from pigs raised on the drug.

China has expressed concerns about the higher concentrations of ractopamine residues found in pig organs, which can be part of a traditional Chinese diet, and the EU has argued that the science backing the drug’s safety is flawed.

In 2009, the European Food Safety Authority published a 52-page report strongly criticizing the data and methodology used by Codex to calculate the Acceptable Daily Intake for ractopamine, upon which the ractopamine MRLs are based.

A report this year by the Food and Environment and Reporting Network found that, according to FDA data, more pigs were reported to have experienced adverse effects from ractopamine than any other veterinary drug.

“Pigs suffered from hyperactivity, trembling, broken limbs, inability to walk and death, according to FDA reports released under a Freedom of Information Act request. The FDA, however, says such data do not establish that the drug caused these effects,” read the report.

A handful of other studieshave linked ractopamine, which is sold commercially as Paylean, to increased aggression and hyperactivity in pigs.