Assessing the hazard potentials of explosives has been an exceptionally difficult endeavor in the past due to the considerable controversies that abound in the area of sensitivity testing. Interpretation of the significance of the various test methods results, conflicting results from apparently similar test methods, and even the definition of the word sensitivity are the frequent subjects of debate among the experts. As a result, very little useful information has filtered down to those who must need it - at the working level. Of paramount concern to those working with or near explosives is their susceptibility to accidental initiation. A method for assessing that hazard by inference from sensitivity test results is described in this report. Sixty-two explosives are ranked in a Susceptibility Index S.I.. Additionally, attention is focused on a few aspects of test procedures and data reporting that has resulted in the publishing of erroneous and misleading information in the past.