Sakrete Concrete/Mortar Dissolver is a safe, environmentally-friendly liquid alternative to aggressive acid concrete removers. Concrete/Mortar Dissolver can be used to remove dried on cement, concrete, mortar, or stucco from most surfaces. Will not harm or fade most surfaces. Use as a spray or soak tools. Works in 15 minutes, 100% biodegradable, non-hazardous formula, contains no acids. Will not harm wood, plastic, metal or paint. Clean up cured concrete & masonry residue on siding, foundations, patios, wooden decks, etc. Deactivates & cleans up with water. 23-oz spray bottle.