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Trust SGS Experts for Dislodgeable Foliar Residue (DFR) Crop Trials in Europe

Seed and Crop NewsSoil, Leaf and Water ServicesSeptember 30, 2021

SGS provides regulatory studies within the SGS Pan-European network. Based on the Guidelines and Regulations (283/2013, 284/2013, 1107/2009, OPPTS 875.2100 and EFSA), we perform thorough DFR studies for different crops and climatic conditions.

What are DFR studies?

DFR studies measure and evaluate residues that can be transferred from treated leaf surfaces onto human skin or clothing. For example, a worker may be exposed when re-entering a treated crop area to pick fruit. DFR study results are used to assess this occupational and residential exposure for humans, and help develop dissipation curves which can be used to calculate re-entry intervals. SGS provides DFR studies under open-field, greenhouse and climate chamber conditions.

Compliance with Good Laboratory Practice

As DFR studies are used to evaluate safety, they are performed according to Good Laboratory Practice (GLP). We conduct DFR studies on representative crops and sites under working conditions, in accordance with the product’s label requirements.

Application of the test substance must match the recommended method for the end-use product, for example via a mist-blower backpack or nozzle-fitted boom sprayer. The objective of the study is to generate a residue dissipation curve. Sampling therefore takes place as soon as the spray has dried, or the dust has settled, followed by a sequence of additional samplings depending on the test substance.

Foliar samples are taken in triplicate in the treated and control plots, with the foliar sample discs directly collected on the test field using a standardized leaf punch sampler. The collected leaf discs are dislodged with a detergent solution and shaken mechanically at the test site, and the dislodging solution is then sent under deep freeze to the laboratory for subsequent pesticide residue analysis.

Foliar Sampling

Climate can strongly influence the dissipation of pesticide residues. Therefore, during the study the local meteorological conditions are also recorded, and if requested additional soil samples are taken. SGS provides testing sites across Europe to assess the expected dissipation in the intended use areas, under different climatic conditions.

Quality Control Along the Way

All our working steps, for example individual sampling intervals, are confirmed with the customer up front and defined in the study plan, and our independent Quality Assurance Unit (QAU) monitors and checks all GLP study data. Additional study adaptations like simulations of morning dew or shading, as well as non-destructive determination of leaf size using a portable scanner, can be included in the study plan.

As a global service provider, SGS strives for best practices to provide your results in accordance with regulatory needs. Our experienced team of field program managers, study directors, analytical staff and our in-house QAU provide GLP-compliant services from study plan to the final report.

For further information, please contact:

Juliane Stolze
Study Director, Field Residue
Im Maisel 14, 65232 Taunusstein
t: +49 6128 744 331

Inga-Mareike Bach
Business Development Manager
Im Maisel 14, 65232 Taunusstein
t: +49 6128 744 569

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