This paper aims at assessing the likely economic impacts of different approaches to implementation of Directive 96/61/EC on integrated pollution prevention and control (IPPC) by establishing a conceptual framework and by providing empirical evidence from case studies in the EU electric steel and domestic glass industry. The potential economic implications of the IPPC permitting process are analysed from the point of view of individual plants. Both plant- and sector-specific factors and the institutional and regulatory context of IPPC implementation in different member states are taken into account. The paper finds only limited evidence of any adverse competitiveness impacts arising from IPPC implementation. Copyright © 2008 John Wiley & Sons, Ltd and ERP Environment.