Global Zoning and Exchangeability of Field Trial Residues Between Zones: Are There Systematic Differences in Pesticide Residues Across Geographies?

Mixed-effects models were used to evaluate the global zoning concept using residue data from a comprehensive database of supervised field trials performed in various countries and regions on a variety of pesticide–crop combinations. No statistically significant systematic differences in pesticide residues were found between zones among the pesticide uses examined. In addition, we conducted a simulation to assess the impact of using regional versus global datasets for calculating maximum residue limits (MRLs). The conclusion of this assessment supports the concept of exchangeability of pesticide residue values across geographic regions and opens the possibility of improving harmonization of pesticide regulatory standards by establishing more globally aligned MRLs. Supplemental material for this article is available online.