MRL calculations based on both intra- and inter-trial residue variability

Area of Science:

• Agricultural Chemistry
• Food Safety Science
• Statistical Modeling

Background:

• Accurate estimation of maximum residue levels (MRLs) is crucial for food safety and international trade.
• Current methods for MRL estimation, including percentile calculations, require robust statistical approaches.
• Addressing intra-trial variability in pesticide residue data is essential for reliable estimations.

Purpose of the Study:

• To introduce a novel mathematical equation for calculating high percentile residue values.
• To develop a method that accounts for intra-trial variability in pesticide residue data.
• To provide a tool for estimating maximum residue levels (MRLs) and supporting regulatory assessments.

Main Methods:

• Development of a Population of Sub-Populations (POSP) mathematical equation.
• Modeling residue incidence as a function of concentration, incorporating intra-trial variability.
• Calculating percentiles by determining residue concentrations corresponding to specific areas under the curve.

Main Results:

• The POSP equation accurately represents a set of supervised pesticide residue trials.
• Results generated by the POSP method are consistent with current OECD calculation methods.
• The POSP approach directly accommodates replicate data and can identify the percentile of the highest residue.

Conclusions:

• The POSP calculation is a valuable tool for estimating maximum residue levels (MRLs).
• The method supports selecting MRL values between the 95th and 99th percentiles.
• POSP enhances the statistical rigor of pesticide residue data analysis for regulatory purposes.