Safety development is of high stakes in work environment, as recent accidents remind us. Despite several paradigms have proposed approaches to characterize and develop safety practices, it appears that more complementarity is still possible based on the consideration of real work. From a case study in the aeronautics industry (metal additive manufacturing), the objective of this article is to present an operationalization of the concept of constructed safety practices.First, an analysis of regulated safety has been done from the actual safety practices prescribed (risk assessment, protection equipment, etc.). Then, a characterization of managed safety practices has been achieved regarding the current work activities and exposure situations to micro and nanoparticles. Finally, one confrontation interview with a worker was a mean to identify constructed safety practices development.Constructive safety appears both in the individual or collective strategy built by the worker, and by the development of safety prescriptions based on a knowledge of managed safety practices. This exploratory work gives prospects to build another theoretical and practical prospect to act on the safety development.