New low-temperature oil-in-water (O/W) type microemulsions that resist freezing and phase separation at -18 degrees C have been developed. These systems were shown to simultaneously destroy, via oxidative and hydrolytic mechanisms, simulants of three chemical warfare agents. Reactions, monitored at 25 degrees C by gradient elution high-performance liquid chromatography, took place instantly or over many minutes, depending upon the particular simulant. Neglecting reaction products, the low-temperature microemulsions contained 11 components: propylene glycol, water, base, oxidant/nucleophile, surfactant, cosurfactant, oil, stabilizer, two nerve agent simulants, and a mustard simulant. Only by virtue of self-aggregation does this extraordinarily complex chemical system adopt a useful molecular organization and, in this limited sense, the microemulsion chemistry resembles what happens in a living cell. Substantial practical issues remain: rates for a recalcitrant VX simulant should be increased and overoxidation of the mustard simulant to a sulfone retarded. Nonetheless, the new system demonstrates once again the potential of microemulsions in carrying out useful organic reactions at realistic substrate concentrations in aqueous solvents.