[en] The Convention on Early Notification of a Nuclear Accident (the 'Early Notification Convention') and the Convention on Assistance in the Case of a Nuclear Accident or Radiological Emergency (the 'Assistance Convention') are the prime legal instruments that establish an international framework to facilitate the exchange of information and the prompt provision of assistance in the event of a nuclear accident or radiological emergency, with the aim of minimizing the consequences. The International Atomic Energy Agency (IAEA) has specific functions assigned to it under these Conventions, to which, in addition to a number of States, the European Union (EURATOM), the World Health Organization (WHO), the World Meteorological Organization (WMO) and the Food and Agriculture Organization of the United Nations (FAO) are full Parties. Since 1989, the arrangements between these organizations for facilitating the practical implementation of those articles of the two Conventions that are operational in nature have been documented by the IAEA in the Emergency Notification and Assistance Technical Operations Manual (ENATOM)1. The manual is intended for use primarily by contact points as identified in the Conventions. Pursuant to the obligations placed on it by the Conventions, the IAEA regularly convenes the Inter-Agency Committee on Response to Nuclear Accidents (IACRNA)2, whose purpose is to co-ordinate the arrangements of the relevant international intergovernmental organizations ('international organizations') for preparing for and responding to nuclear or radiological emergencies. Although the Conventions assign specific response functions and responsibilities to the IAEA and the Parties, various international organizations have - by virtue of their statutory functions or of related legal instruments - general functions and responsibilities that encompass aspects of preparedness and response. Moreover, some regional organizations (e.g. the European Union) are party to legally binding treaties and have directives and regulations that bear on emergency response arrangements among some States. There are also bilateral agreements between some international organizations that also have relevance to preparedness and response arrangements. In March 2002, the IAEA issued Safety Requirements, entitled 'Preparedness and Response for a Nuclear or Radiological Emergency' (GS-R-2), jointly sponsored by the FAO, IAEA, the International Labour Organization (ILO), the OECD Nuclear Energy Agency (OECD/NEA), the United Nations Office for the Coordination of Humanitarian Affairs (OCHA), the Pan American Health Organization (PAHO) and WHO. These safety standards imply additional expectations with regard to operational emergency response arrangements. It is recognized by the participating organizations, and reflected in the above requirements, that good planning in advance of an emergency can substantially improve the response. With this in mind, the IAEA, the organizations party to the Conventions, and some other international organizations that participate in the activities of the IACRNA develop and maintain this 'Joint Radiation Emergency Management Plan of the International Organizations' (the Joint Plan), which describes: the objectives of response; the organizations involved in response, their roles and responsibilities, and the interfaces among them and between them and States; operational concepts; and preparedness arrangements. The various organizations reflect these arrangements in their own emergency plans. The IAEA is the main co-ordinating body for development and maintenance of the Joint Plan. All States irrespective whether they are party to one or other of the two Conventions are invited to adopt arrangements that are compatible with those described here when providing relevant information about nuclear or radiological emergencies to relevant international organizations, in order to minimize the radiological consequences and to facilitate the prompt provision of information and assistance. This document is the fourth edition of the Joint Plan. The third edition was co-sponsored by the European Commission, EUROPOL, FAO, IAEA, INTERPOL, OCHA, OECD/NEA, OOSA, PAHO, UNEP, WHO and WMO in co-operation with the International Civil Aviation Organization (ICAO). The present edition is additionally co-sponsored by the International Maritime Organization (IMO) and in co-operation with United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). The Joint Plan does not prescribe arrangements between the participating organizations, but describes a common understanding of how each organization acts during a response and in making preparedness arrangements. It describes the arrangements as envisaged from 1 December 2006, by which time each participating organization needs to have initiated the steps necessary for harmonizing its own response plans and arrangements with the 2006 edition. The subsequent edition is envisaged for release in December 2008. Although a controlled distribution list is maintained for the Joint Plan and any amendments, it is not restricted in its availability. An up-to-date version is maintained on the IAEA's public web site under http://www-ns.iaea.org/tech-areas/emergency/inter-liaison.htm