In thisarticle, the γ-radiolysis of trioctyl phosphine oxide (TOPO) regarded as the typical representative of trialkyl phosphine oxide (TRPO) composites has been studied. The irradiated sample solutions were extracted with 5% Na2CO3 aqueous solution, then washed with triply distilled water. The emulsification phenomenon was foundduring thewashing process. The extent of emulsification was dependent on the absorbed dose and the pH value of the system. IR and UV spectroscopy as well as elemental analysis were used to determine the structures of the final products. The resultsindicated that the main scrubbed products werephosphinic acid, its ester and an oligomer of TOPO whichinduced emulsification and produced permanent damage on TOPO.