An Update to the Universal Risk Scales – A Tool for Developing Risk Criteria by Consensus How safe is safe enough?

PresentationIn 1999, the Risk-Based Explosives Safety Criteria Team (RBESCT) developed the Universal Risk Scales (URS) to assist in the job of selecting appropriate criteria for defining “How safe is safe enough?” To answer this question, the URS provides two types of numerical data plotted alongside a logarithmic scale. On the left side, the URS summarizes legal precedents and standards that contain criteria for risk acceptance and compares those standard criteria to numerous data on the right side representing actual risk statistics derived from historical accident data. The URS was the foundation for selection of the risk criteria currently used by Department of Defense Explosive Safety Board (DDESB) to evaluate risk-based explosives safety siting assessments. In 2014, A-P-T Research (APT), with guidance from the RBESCT, was tasked to update the URS to reflect changes in the safety culture since the initial study. More current data were collected to update risk values from the previously used activities, and new activities were researched in an attempt to better represent risks similar to the explosives industry. In addition, all standards mentioned in the initial study were compared to see if any updates were made, and new standards were included in the comparison. This research will be evaluated and assessed by the RBESCT and DDESB to determine if current Department of Defense (DoD) site planning criteria need revision. This paper provides the details of this update along with additional perspectives and comparisons with the updated and new data. This updated URS data also has many other potential uses within government and industry for decision makers who face the challenging question of “how safe is safe enough?