6. Characterize and classify different accident phenomena

This involves characterizing and classifying the various phenomena and potential accidents in terms of the intensity of the effects of the phenomena, the severity of the consequences of the accidents, and the probability and kinetics of development, taking into account the performance of prevention and protection measures.

The initial classification based on the preliminary risk analysis results in the identification of phenomena requiring a more detailed analysis of all possible scenarios. Scenarios with large-scale effects, whatever their probability, are subject to an additional risk reduction analysis at source, based on the state of the art, even if they have not been identified in the accidentology.

This involves assessing the criticality of the risk.