A hazardous material compatibility storage guideline and an abbreviated hazardous material compatibility storage tool, both consistent with center for chemical process safety (CCPS) guidance for managing chemical reactivity hazards, were developed for sites storing reactive materials. The hazardous material compatibility storage tool assists personnel in developing and documenting appropriate storage strategies. The tool identifies potential hazardous combinations of materials for material handlers and suggests storage strategies that minimize the risk of such combinations. This tool is formatted as a template and is adaptable to address storage in warehouses, laboratories, and production buildings, where drum quantities of materials are stored. Development of the tool included trials at various facilities storing reactive materials. These trials included analyzing current storage strategies at these locations determining suggested strategies based on a hazardous materials compatibility storage matrix referencing a small quantity exemption table finalizing appropriate strategies based on suggested strategies and the overall risk (i.e., literature searches, laboratory data, engineering and administrative controls) conducting literature searches and laboratory tests when Material Safety Data Sheets information was insufficient to determine storage strategies. (c) 2006 American Institute of Chemical Engineers Process.