New IZSC Harmonisation Document on DFR Study Evaluation: A new harmonization document on the evaluation of Dislodgeable Foliar Residue (DFR) research has been approved by the Interzonal Steering Committee (IZSC). The document, which was approved at the IZSC meeting on September 10, 2026, will be applicable to applications for plant protection product (PPP) authorization that are submitted starting on March 10, 2027.

In order to improve the default DFR values used in the first-tier exposure assessment for employees and bystanders/residents, DFR studies are increasingly included in Registration Reports submitted under Regulation (EC) No 1107/2009. DFR studies may also help refine default dissipation rate (DT50) values when foliar residue decline is examined at several time points after treatment.

While criteria for conducting experimental DFR studies are already provided in Appendix J of the EFSA Guidance on the assessment of exposure of operators, workers, residents, and bystanders (EFSA Journal 2022;20(1):7032), Member States recognized the need for additional agreements to encourage a more uniform evaluation of such studies across Member States.

While acknowledging that some parts call for expert judgment and that case-specific or ad hoc procedures may be required, the new harmonization document offers additional methods for the assessment and derivation of DFR values. This document would be superseded by any future agreements or revisions to the pertinent EFSA guidelines.

Key Date: New IZSC Harmonisation Document on DFR Study Evaluation

Relevant to PPP authorization applications filed starting on March 10, 2027.

The document represents the seventh revision, with the final version endorsed by the IZSC in September 2026.