Physiochemical properties such as density, viscosity, interfacial tension (IFT) and phase disengagement time (PDT) were measured after subjecting tri-iso-amyl phosphate (TiAP)-based solvent systems to hydrolytic treatment at 40 and 50 degrees C, for 400 h. The change in viscosity between the degraded and fresh solvent was significant compared with the change in density, which could be due to the formation of intermediate compounds susceptible to hydrogen bonding. The marginal variation in the IFT values even after accelerated treatment and the absence of any new class of compounds after treatment, as evidenced by FTIR spectral analysis, revealed that the solvent exhibited good thermal and chemical stability.