Joint development of a new Agricultural Operator Exposure Model - Project Report

A predictive model for the estimation of agricultural operator exposure has been developed on the basis of new exposure data. More than 30 unpublished GLP exposure studies conducted between 1994 and 2009 mainly for the purpose of plant protection product authorisation were chosen for evaluation according to a set of quality criteria defined by an expert group. All data including information about the studies were compiled in a database and used for a statistical analysis of exposure factors. The statistical analysis resulted in six validated models for typical scenarios of pesticide mixing/ loading, and application outdoors including downwards and upwards spraying with vehicle-mounted/-trailed or hand-held equipment. As a major factor contributing to the exposure of operators, the amount of active substance used per day was identified. Other parameters such as formulation type, droplet size, presence of a cabin or density of the canopy were selected as factors for particular sub-scenarios. However, in the case of knapsack mixing/loading, and hand-held application directed downwards, the number of data was too small for identifying reliable exposure factors; instead the relevant percentiles of the exposure distribution were used. The new operator exposure model represents current application techniques and practices in Europe and allows for a tiered approach considering personal protective equipment (if necessary). The new model is intended to be used for national authorisation and for registration procedures of plant protection products in the EU. 2