Sociological research on expertise sheds useful light on changes in this field since the late 1990s in France. It also shows the emergence of new games between actors, which have to be understood, and highlights the inertia of action systems and socio-cognitive frames. The review of research on expertise allows the identification of three contrasted models of expertise which embed different notions of risks, knowledge, and patterns of interactions between experts, stakeholders, concerned groups and policy makers: the standard model, the cross-examination model and the hybrid forum one. While the proceduralization of expertise is an important trend, it would be dangerous to perceive it as the only goal of the democratization of risk management. This would mean forgetting that risks are situated at the intersection between two regimes of action: the first is short-term and motivated by the urgency of threats and the need for preventive and corrective measures; the second is long-term, with the transformation of technical systems and the creation of new competencies. The problematical situations characterised by complexity, uncertainty and ambiguity - are those in which the articulation between these two regimes is both indispensable and extremely difficult. In these cases the proceduralization of expertise must be coupled with a set of devices, still to be invented, which allow for the articulation of these two regimes of action.