This European Standard contains terms and definitions for CBRNE (chemical, biological, radiological, nuclear, explosive) applications. Common understanding and communication is important in the implementation of an effective CBRNE response and this communication will be most effective if there is common understanding of the terms used. Many of the terms and definitions listed here have been widely used for many years, while others are the result of cross-cutting experience of areas of CBRNE. The gradual evolution of our understanding of CBRNE and response measures means that CBRNE terminology will continue to develop.