This is an exceptional sponge and a must for soot removal. Use it dry to clean any surface - it actually absorbs a tremendous amount of soot/dirt into the cells of the sponge. Made of volcanized natural rubber. It is completely safe and non-toxic. These are known as chemical sponges. PLEASE NOTE: These sponges DO NOT and is not intended to remove set in stains such as nicotine burns or fire burns. They remove soot that was left from the smoke of a fire that will release from the surface.