UNEP, in collaboration with the contributors from defence forces, has developed this tool-kit for national security and the environment, focusing on ozone and climate issues. It has drawn inputs from workshops and international conferences held on military and environment protection, as well as real-life experiences and good practices from different parts of the world. The main purpose of this document is to provide information to defence establishments across the globe so that they can design and implement ozone-friendly approaches in their regular equipment operation and maintenance activities.