Umzi-mveliso Iofisi Isatifikethi Umboniso Zama Uvavanyo lwephepha lokunyanga inkunkuma yamanzi Uvavanyo lwepropylene glycol kunye ne-surfactant yonyango lwamanzi amdaka Uvavanyo lwenkunkuma yegwele elibomvu lamanzi kunyango lokubilisa irayisi