EFF-ERAYZA: Efflorescence Remover (QT) Highly effective for removing common mineral reasidues including: efflorescence, grout haze, rust marks, soap scum, limescale and mortar mess. Eff-Erayza can also be used for removing fireplace soot. The power of dangerous traditional acids without the noxious fumes Temporary contact does not burn skin - you have some time to rinse off theEff-Erayza (however, rinse immediately after skin contact) Almost zero corrosion of metals, except uncoated aluminium