Foreword In the late 1980s@ the International Maritime Organization (IMO) started work on prevention of air pollution from ships. These efforts were based on scientific information on adverse effects of emissions to air from a multitude of sources@ ships being one of them@ on vulnerable ecosystems. This was something of a departure@ as IMO's focus@ along with that of national regulators and of society as a whole@ had previously been on more visible sources of ship-sourced pollution ?C for example@ on oil spills resulting from major ship accidents. The harmful long-term effects of ships' exhaust gases on human health and the environment were not so immediately visible and had not earlier been fully recognized. The seventeenth session of the IMO Assembly@ in November 1991@ recognizing the urgent necessity of establishing an international policy on prevention of air pollution from ships@ considered and decided@ in resolution A.719(17)@ to develop a new annex to the International Convention for the Prevention of Pollution from Ships@ 1973@ as modified by the Protocol of 1978 (MARPOL Convention). Following development of the regulatory text by IMO's Marine Environment Protection Committee (MEPC)@ an International Conference of Parties to the MARPOL Convention was held in London from 15 to 26 September 1997. The Conference adopted the Protocol of 1997 to the MARPOL Convention@ which added a new Annex VI@ Regulations for the Prevention of Air Pollution from Ships@ to the MARPOL Convention (MARPOL Annex VI). The Conference also adopted@ by Conference resolution 2@ the Technical Code on Control of Emission of Nitrogen Oxides from Marine Diesel Engines (NOx Technical Code)@ which is mandatory under MARPOL Annex VI. The 1997 Air Pollution Conference was a historic response by IMO to the need to minimize emissions from ships and their contribution to global air pollution and environmental problems. With the objective of achieving the desired reduction of NOx in the future@ the 1997 Conference requested that the MEPC review the NOx emission limits at a minimum of five-year intervals after the entry into force of MARPOL Annex VI@ and amend them as appropriate. Following the entry into force of MARPOL Annex VI on 19 May 2005@ MEPC 53 (July 2005) agreed to the revision of MARPOL Annex VI and the NOx Technical Code with the aim of significantly strengthening the emission limits in light of technological improvements and implementation experience@ and then instructed the IMO Sub-Committee on Bulk Liquids and Gases to prepare the draft amendments to MARPOL Annex VI and NOx Technical Code. As a result@ MEPC 58 (October 2008) considered and adopted the revised MARPOL Annex VI and the NOx Technical Code 2008@ which are expected to enter into force on 1 July 2010 upon their deemed acceptance on 1 January 2010. This publication contains the revised MARPOL Annex VI and the NOx Technical Code 2008@ as well as additional information relevant to the prevention of air pollution from ships. A number of guidelines and other non-mandatory instruments will be developed or updated as a consequence of the revision of MARPOL Annex VI and the NOx Technical Code. These guidelines and other non-mandatory instruments will be published in a separate publication in 2010. For further information@ see the Future developments section of this book.