Soap scum can be effectively removed by using an appropriate surfactant with a chelating agent at a high solution pH. The equilibrium solubilities and dissolution rates of two model soap scums [calcium stearate and magnesium stearate: Ca(C 18 ) 2 and Mg(C 18 ) 2 ] were investigated in aqueous solutions containing three different types of surfactants [methyl ester sulfonate (MES) as an anionic surfactant; alcohol ethoxylate (EO9) as a nonionic surfactant; and dimethyldodecylamine oxide (DDAO) as an amphoteric surfactant] in the presence of different biodegradable chelants: trisodium ethylenediamine disuccinic acid (Na 3 EDDS) and tetrasodium glutamate diacetic acid (Na 4 GLDA) compared with disodium ethylenediamine tetraacetate (Na 2 EDTA), a chelant with poor biodegradability. The highest equilibrium solubility and dissolution rate of either soap scum were observed at high pH in the DDAO system with Na 4 GLDA. In addition, the calcium soap scum had a similar to higher equilibrium solubility and a higher dissolution rate constant as compared with the magnesium soap scum.