Since the first Seveso Directive was issued 25 years ago, each Member State of the European Union developed own regulations to enforce its application. The lack of a common approach generated differences between Member States, or even between regions within a Member State, which in practical terms caused that establishments falling under the field of application of the Seveso Directive face a different level of requirements. This situation causes significantly different impact on social, technical and financial aspects. Factors like industrial background, accidental history, actual land use, social attitude towards risk, economical and political structures play an important role in how the decisions about hazardous activities are perceived and handled. Answering the question: "Is there a right methodology for the assessment of the risk of major accidents?" may be sterile or impossible. Many tools are appropriate and the main concern is to use them properly. Technically, the causes and consequences of, e.g., a fire in a port in Spain on the Mediterranean Sea or in the port of Basel (Switzerland) in the Rhine River could be assessed using the same methods and criteria, but this is not usually the case. This paper shows, with practical examples, the differences existing while applying different regulations in the field of prevention of major accidents and the potential effects that these differences may generate regarding the definition and management of emergency plans outside establishments. If the existing unequal situation is not faced, the comparative disagreements between Member States will prevail. Therefore, the application of the Seveso Directive will generate a different impact on the society, operators and regulators, and may become a factor which may cause a risk transfer between Member States. Efforts should be addressed to harmonize criteria in this subject. (C) 2008 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.