Plant protection products are essential in agriculture, helping farmers safeguard crops from pests, fungal diseases, and weeds. Understanding their behavior in the environment is crucial for protecting non-target organisms in nearby areas. Recent studies have identified volatilisation, short-range transport, and deposition of pesticides from the air as significant pathways for these substances to enter habitats of aquatic and terrestrial non-target organisms. In 2002, the German Federal Consumer Protection and Food Safety Agency (BVL) released guidelines to assess these pathways for the authorization of plant protection products. This assessment involves a tiered approach of model calculations and field experiments, both of which revealed uncertainties in predicted concentrations due to the complex nature of these processes. Consequently, further research was deemed necessary. The primary aim of this project was to develop a large-scale outdoor wind tunnel test system for accurate measurements of atmospheric short-range transport and dry deposition of volatilised pesticides, enhancing existing models and testing methods. The behavior of ten pesticides, representing diverse physical and chemical properties, was examined through fifteen semi-outdoor wind tunnel experiments, covering various experimental conditions. The findings led to an empirically derived correlation that describes deposition after volatilisation based on vapo
