BP had used a rigorous pre-startup procedure prior to the incident that required all startups after turnarounds to go through a PSSR.29 While the PSSR had been applied to unit startups after turnarounds for two years prior to this incident, the process safety coordinator responsible for an area of the refinery that includes the ISOM was unfamiliar with its applicability, and therefore, no PSSR procedure was conducted. If the PSSR, which called for a formal safety review by a technical team led by the operations superintendent, had been implemented, a technical team would have verified the adequacy of all ISOM safety systems and equipment, including procedures and training, process safety information, alarms and equipment functionality, and instrument testing and calibration. The PSSR required sign-off that all non-essential personnel had been removed from the unit and neighboring units and that the operations crew had reviewed the startup procedure. Higher level management, such as the Texas City Operations Manager and Process Safety Manager, were required to sign off on the PSSR checklists and authorize the startup. However, none of the PSSR procedural steps were undertaken for the ISOM startup.