Tetra-n-octylammonium bromide is associated with benzethonium chloride and used as a disinfectant, in surface treatment and preservative in hospitals and industries. It is used as a surfactant involved in the synthesis of blue-luminescent silicon nanoparticles in order to get uniform particle size. It is utilized as a cationic additive in the preparation of membranes using cyclam derivative 1,4,8,11-tetra(n-octyl)-1,4,8,11-tetraazacyclotetradecane as an ionphore and dibutyl phthalate as plasticizers.