Operator expositions depend of the practices and are evaluated by mathematical models during the application of marketing authorization. The variables and the modalities used in both risk assessment models represent an official use of pesticides. However these models are old. The aim of this study is to highlight how these models are outdated, and how they can be improved. Constructors and experts were interviewed. Operators were observed during pesticides manipulations. The causes of expositions can be separated in two categories: Direct and Indirect. Observations show moreover that sprayers are the most relevant factor, influencing the actions of the operators, and so an important part of their final exposition to pesticides. Many types of equipment installed and accessories used play an important role, especially in the organization of the manipulations. They cannot be neglected any more in both models. Many ideas are shown in this study to improve devices and so reduce the pesticides expositions.