SEOUL, South Korea – Starting in June, South Korea will allow designated levels of Zilmax in beef, Reuters reported. South Korea's food ministry announced in November 2013 plans to end its zero-tolerance policy on zilpaterol after a government risk assessment found Zilmax could be permissable at certain levels.

South Korea will allow 1 part per billion (ppb) of Zilmax in beef muscle and 5 ppb in beef liver, according to the report.

South Korea suspended some imports of US beef supplied by Greeley, Colo.-based JBS USA, after zilpaterol was found in the meat. South Korea was one of many Asian countries that banned feed additives such as zilpaterol.

Zilmax [zilpaterol hydrochloride] came under intense scrutiny after Springdale, Ark.-based Tyson Foods, Inc. announced it would stop buying cattle fed zilpaterol on concerns the feed additive was causing lameness and negatively impacting the quality of beef. Merck Animal Health, which manufactures Zilmax, stopped sales of the product in August 2013 and announced it would conduct a scientific audit to monitor the process of feeding Zilmax to cattle.