International collaboration within environmental technology education is seen as one of the tools for an international dimension in the prevention and cure of environmental problems. Several different models for international collaboration have been found: researcher education, university-enterprise collaboration, summer universities, international organizations' activities, East-West and North-South university collaboration. International collaboration is found both within pollution prevention and pollution control. Tools found are: PhD programme, researcher course programme, student courses, student exchange, student-placement exchange in enterprise, university-university exchange, university-enterprise exchange, train-the-trainers activities, transfer of concepts, exchange of concepts, workshop and conferences, surveys and inventories, and working groups.