NAFTA Maximum Residue Levels (MRL) Calculator
The MRL Calculator is a spreadsheet developed by the NAFTA MRL/Tolerance Harmonization Workgroup to calculate statistically-based pesticide tolerances (i.e., maximum residue levels, MRLs) using field trial data. The NAFTA MRL Calculator, guidance document (with instructions), and the White Paper (which provides rationale and simulations supporting the use of the calculation methods used in the spreadsheet) are available below. Beginning April 1, 2011, Canada and the United States joinedthe other OECD member countries in their use of the OECD MRL Calculator to calculate pesticide MRLs. The OECD MRL Calculator replaces and supersedes the NAFTA MRL Calculator. The OECD MRL Calculator and supporting documents are available for download from EPA’s website for the OECD Working Group on Pesticides. A brief fact sheet providing background information on the NAFTA MRL Calculator and the transition to the OECD MRL Calculator is also available.
- NAFTA MRL Calculator (spreadsheet, 8.1 MB)
- Guidance for Setting Pesticide Maximum Residue Limits Based on Field Trial Data (EPA-HQ-OPP-2007-0632-0003)
- Statistical Basis of the NAFTA Method for Calculating Pesticide Maximum Residue Limits from Field Trial Data (EPA-HQ-OPP-2007-0632-0002)