Operator exposure studies (OPEX)
Operator Exposure Studies (OPEX), important studies to reach regualtory approval, assess the impact of a crop or agrochemical product that could be inhaled or absorbed orally or dermally during mixing, transport or application.
A first-tier study uses modeling, based on known properties of the product and factors such as application methods. When reference values are exceeded, higher tier studies are carried out in the field.
These types of studies may include passive dosimetry (trapping the substance on a whole-body absorbent garment), biomonitoring (via urine testing) and air sampling (via a tube at lapel level, connected to a pump and sampling device).
Exposure routes are modeled after real-world exposure risks, typically dermal or inhalation-based, and study designs are constructed with the aim of replicating real-world operation conditions.