IUCN EICAT categories and criteria : first edition
A unified classification of alien taxa based on the magnitude of their environmental impacts has been developed in response to these issues. EICAT (Environmental Impact Classification for Alien Taxa) is a simple, objective and transparent method for classifying alien taxa in terms of the magnitude of their detrimental environmental impacts in recipient areas. Based on evidence on the impacts they have been causing on native taxa in their introduced range, alien taxa are classified into one of five impact categories.