Chemical and physical property studies of Caustic-Side Solvent Extraction (CSSX) have been continued to provide fundamental data for process knowledge and design activities. The overall conclusion of the FY02 physical and chemical property studies is that the CSSX solvent meets all of the performance requirements within the bounding conditions defined by the Savannah River Site waste. These studies also showed that the chemical and thermal degradation under the operating conditions of the process is slow relative to the goal of one annual solvent replacement. This work also supported other tasks in addressing the radiation-stability risk, providing analytical and performance data showing that the solvent can withstand the dose equivalent of several years without the need for solvent washing.