Against the background of future international regulations for marine diesel exhaust gas, the paper describes in brief the purpose of the intended IMO-Code on the emission of nitrogen oxides. In this connection, the joint research project CLEAN and the tasks of Germanischer Lloyd (GL) will be presented as dealing with the measurement technology used to analyse the gaseous components of marine diesel exhaust gas and to sample exhaust particles. Equipment and procedures are presented shortly whilst discussing the necessary knowledge to assess the exhaust emission behaviour of a diesel engine. Emphasis will be laid on the description, measurement and the analysis of the paniculate matter in the diesel engine exhaust gas. The method as well as the equipment used for sample collection and analysis of the composition of the particles will be described more closely. General requirements for onboard measurement equipment are stated. 1. from Ships The increasing demands for environmental protection in shipping as well as in other fields are being answered by the International Maritime Organization (IMO) with further development of the rules. At present, an Air Pollution Annex to MARPOL is being compiled. Its purpose is inter alia to regulate the emission limits for the oxides of nitrogen (NOx) and sulphur (SO:). A 'step by step' solution for implementation of the limit values for the nitrogen oxides is intended. This means that the permissible limit values defined in the Annex will be reduced further in phases according to technical progress and environmental needs at later stages. Diverse strategies for implementing low-emission ship propulsion plants are also in the centre of the deliberations: progressive port duties as an economic incentive for low-emission propulsion units, for example. It may be expected that future developments will be characterized by more stringent limit values, by an extension with respect to the size and number of regions with Transactions on the Built Environment vol 24, © 1997 WIT Press, www.witpress.com, ISSN 1743-3509