French chemical companies on studying major hazards prevention through an understanding of multiple interactions between artefacts, internal and external actors, organisation and institutions (Dupré/Le Coze, 2021a). We studied 5 companies, spending several weeks observing and interviewing people representing different expertise, from control room operators to plant manager. Our aim through this panel of chemical plants, following Short’s proposition, is to study « the social transformation of risk prevention » : « Institutions and communities, nations and economies are affected by choices made as to hazards to be attended to and risks to be tolerated or resisted. It is with regard to theses contexts that the nature of risks and risk perception can be informed by sociology. » (Short, 1984, p.716) So, to complement to the traditional approach exploring the regulator-regulatee relationships in national contexts (Dupré/Le Coze, 2009), we look into the practices of people in subsidiaries in their mediating roles between two different types of external entities, on the one hand the corporate functions of the MNEs and on the other hand, the national regulators. From this angle, we learn from their modes of interactions supporting the improvement of safety practices. We follow a bottom-up methodological approach, giving us the opportunity to think about the inter-organisational boundaries and the mutual power of both the subsidiaries and the MNEs in a globalised context (Le Coze, 2017). In other words, we not only show in this paper « an example of the most common contemporary form of organizational accommodation to legal rules » (Silbey/Agrawal, 2011, p.86), but a more complex situation of organisational accommodation to both regulatory national rules and MNE’s (internal) standards.