Optimizing exposure data collection for plant protection products: identifying ideal collectors with the fluorescent dye pyranine

When approving plant protection products, exposure data are required for risk analysis. Exposure data can be collected for various exposure pathways, such as dermal, inhalation or ground sediment. For measuring exposures, pyranine, a fluorescent dye, and a collector can be used. However, the choice of collector material depends on the specific exposure pathway. This study aims to determine the most suitable collector, in combination with the tracer pyranine, for recording exposure through different pathways in practical trials. Seven different collectors (Tyvek®, labels, plastic patches, paper patches, nylon filters, fibreglass filters, petri dishes) were subjected to laboratory and field tests to assess various quality parameters. Blank values, recovery rates, storability, and fluorescence degradation under UV-radiation were measured. Based on the results, a matrix was created summarizing which collector might be best suited to capture each exposure pathway. Almost all collectors demonstrated high recovery rates (Tyvek® 100