The present work introduces a new method for assessing the environmental risk of industrial processes. The method defines a global environmental risk assessment (GERA) index for a new or existing process. Such an index is based on newly defined environmental risk indices for chemical components present in the inlet and outlet process streams and the different unit operations constituting the given process. As an illustration, the method has been applied to two case studies involving typical processes employed to produce (1) sodium carbonate and hydrogen chloride. and (2) methyltertiarybutyl ether. Our analysis indicates that the proposed method can be easily implemented into a process simulator to calculate the GERA indices for competing processes, thus accounting for the environmental impact of the process at the design stage. (c) 2004 Elsevier B.V. All rights reserved.