This paper analyses cur-rent trends in the development and use of acute exposure levels in Europe for the implementation of the Seveso II Directive [Council Directive 96/82/EC of December 9, 1996 on the control of major-accident hazards involving dangerous substances. Official Journal of the European Communities, vol. L 10, January 14, 1997, Luxembourg, pp. 13-33]. It also describes a new initiative to develop a European methodology for deriving acute exposure threshold levels that responds to emerging needs in this area. The need for acute exposure values to predict human health effects of potential accidents on exposed populations has burgeoned in recent years. As the driving legislation for managing industrial hazards in Europe, the Seveso II Directive has particularly influenced this trend. Yet at this time it is questionable whether the availability and range of acute exposure values for toxic substances has kept apace with the growing need. Results of a survey of Seveso II competent authorities in the EU-15 revealed that a variety of different types of acute exposure values (AEGLs, EPRGs, etc.) are used for Seveso II applications. Moreover, a comparison of these values indicates gaps in coverage of substances as well as inconsistencies in terms of how health effects and exposure periods are defined for each type. These findings highlight an opportunity for greater collaboration on scientific inputs to application of the Directive in Europe. The ACUTEX project is an EU-funded research project aimed at furthering scientific exchange and collaboration in support of the development of acute exposure levels for toxic substances in Europe. Its goal is to develop a European methodology for deriving acute exposure threshold levels (AETLs). In particular, it provides the possibility for a common European platform for developing additional acute exposure values to meet emerging needs and cover more chemical substances. To maximise success, the work plan is designed to meet two very important challenges, the need to complement and add value to the existing array of acute exposure methodologies and the necessity of meeting requirements of a diverse range of European stakeholders. As such the project will draw on collaboration among European scientists and process of deliberation among stakeholders to deliver the following key results: (1) to facilitate wide acceptance of the methodology in Europe by both the scientific community and communities of different end-users; (2) to provide greater equivalence and transparency in implementation of the Seveso II Directive across the Member States, specifically through the development of common scientific bases for assessing risks and making risk management decisions related to toxic releases; (3) to produce a methodology that remains open to future collaboration on derivation of acute exposure levels on a European and a global basis. (c) 2005 Elsevier B.V. All rights reserved.