SPS(Bis-(sodium sulfopropyl) disulfide) CAS:27206-35-5 Trade name SPS(SP) Chemical name Bis-(sodium sulfopropyl) disulfide Molecular formula C6H12O6S4(Na)2 Assay 90% Appearance White or yellowish powder Application As a brightening agent for acid copper baths for decorative and functional deposits, it is functionally compatible with most components of typical copper bath formulation such as non-ionic surfactants, polymeric amines and other mercapto compounds.