The Umatilla Chemical Agent Disposal Facility (UMCDF), Umatilla, Oregon has had fires in the Explosive Containment Rooms (ECRs) during the shearing operation of GB M-55 rockets. Additionally, the Pine Bluff Chemical Agent Disposal Facility (PBCDF, Pine Bluff, Arkansas) has also had fires in their ECRs (Table 1). These M55 rockets are small field units designed and built in the early 1960's. The warheads were filled with the chemical agent Sarin (GB). These rockets have been stored awaiting destruction as outlined in the Chemical Weapons Convention, signed in 1993 and ratified in 1997. The Chemical Materials Agency (CMA) formed an ECR Rocket Fire Working Group to better understand what was causing the fires. The group consisted of several organizations and subject matter expects to assist the United States Army during the investigation. At the request of the CMA, (Edgewood, MD), ARDEC (Picatinny Arsenal, NJ) was tasked to perform compositional analyses, compatibility, and sensitivity (friction, impact and electrostatic discharge) testing to determine if the M28 propellant is a possible root cause of the fires experienced during demilitarization operations at UMCDF and PBCDF. CMA developed a plan to separate the warhead section from the rocket motor section on nine rockets in storage at UMCD and nine rockets at PBCA. The rocket motor sections were sent to Picatinny Arsenal where they were further disassembled, inspected, and sampled in a controlled manner. The rocket propellant was examined for migration of nitroglycerine, loss of stabilizer and other signs of degradation and increased sensitivity.