A large variety of methods exist for identifying and assessing the hazard potential of chemical processes during the design phase. These methods vary significantly in goal, scope, structure and the exact way of considering safety aspects. After a theoretical discussion of the key characteristics of such assessment procedures, selected methods are applied to nine different processes. The results show that if two different assessment methods are used for comparing two processes in order to identify the more dangerous one, in 75% of the cases both methods deliver the same result. In general, good agreement was obtained between methods assessing the energy that can be potentially released, as long as the methods consider not only fire and explosion but also reaction and decomposition. Results from toxicity assessment vary significantly depending on the toxicological endpoint considered and on the substance property used for assessing toxic effects. Furthermore, the disadvantages of using discrete qualitative instead of continuous quantitati ve properties are highlighted using mass as an example. The results clearly show the high dependence of the results on the selected assessment method. Thus, the selection of a method for a given purpose has to be made carefully and the user should be aware of its characteristics and their influence on the results obtained.