During the twentieth century the domain of industrial medicine and industrial diseases has been a scene of crucial struggles at the transnational level. Based on the cases of silicosis and pneumoconiosises the article examines the role of international institutions in this process (ILO, LoN, WHO, ECSC). As the relationships between Luigi Carozzi, Albert Thomas and Ludwik Rajchman show, their interactions mix cooperation and concurrence and consequently have an impact on the internal structure. Changes in the action models are the result and the taking into account of immission loads and a global work environment as well as the relations between industrial hygiene and industrial security, is partially to be considered as a result of this game in which diplomacy and expert knowledge, but also the pressure of employers, trade unions and erudite associations and societies come into operation. The concept of health at work leads us to consider the European Union as the inheritor of these dynamics which were conceived to articulate social protection and health protection with the free play of market forces.