Term used for an officially established upper allowable limit, of a given compound (e.g., a synthetic hormone) in a particular product, such as meat. For example, in 1994, the Codex Alimentarius Commission in Rome, Italy decided to establish maximum residue levels for each of five growth promotants that are commonly utilized by the U.S. beef industry. Because the World Trade Organization (WTO) subsequently stated that it would respect MRLs, a WTO member nation cannot legally refuse to allow import of meat products on growth promotant-content basis if the content of the promotant contained in the meat is less than its maximum residue level.