In this research project we choose to analyze risk assessment in the context of risk regulation, and therefore observed a European Commission’s procedure on pesticides risk. We paid a particular attention to the transformations resulting from negotiations of the “risk” concept within the European public sphere. This work tries to answer different issues related to risk: “pesticides” associated with “risk” as a social problem, the European Commission’s attempts to promote a rational public space of discussion and the question of contexts at the center of sustainable development policies regarding risk. The complex nature of the European legal environment leads us to adopt a techno-semiotic methodology, developed in Communication Studies, by analyzing the links between documents, media – especially digital media – texts and discourses. We investigated the construction of pesticide risks as a social problem via the European Commission’s procedure: it crystallizes the interests of many stakeholders on the question of pesticide risks, but also shows their implication in a larger debate about risk assessment and sustainable development. This work then helped us to understand how the European Commission managed to create a space for rationality, an entente between the stakeholders. This entente shoulders the possibility of a common world, of a common definition of risk. Finally, the discursive strategies of the stakeholders are also focused on the re-contextualization of the concept of "risk". The challenge for those involved in the procedure is less to change the definition of "risk", than to raise the legislator awareness on the complexity of the problem in different environmental, societal and economic contexts. The goal of future risk researches can thus be to understand the “equipment" from the risk concept with these different contexts.