Are safety and security in industrial systems antagonistic or complementary issues ?

International audience; This paper addresses the issues resulting from the concomitant allocation of safety and security objectives to an industrial facility. The authors analyse the liaison between the concepts of security and safety They attempt to describe the possible disconnections or even contradictions between them, as well as the benefits expected from increased disciplinary exchanges between safety and security studies. The first section of the paper introduces to key security challenges and threats in industrial facilities. The second section briefly reviews, on the basis of available literature, the major differences between a safety study and a security assessment for a given industrial facility. The third section discusses the boundary conditions for security-related application of probabilistic and deterministic risk assessment methodologies usually applied in safety studies. The fourth section presents situations where safety and security objectives appear to have been inconsistent. Examples include: risks caused by false alarms, increased complexity of operating procedures, risks caused by active security measures, negative effects of barriers accumulation, competing rationalities or paradigms . . . The authors conclude that safety and security objectives are not easily compatible on an industrial facility and those innovative scientific paradigms and methods need to be developed so that operators of industrial facilities can consider a more integrated approach