ACS helps remove glazed and tarry creosote buildup from your chimney. Daily use will prevent future buildup of dangerous creosote. ACS is a non-toxic, non-corrosive, non-flammable, water-based catalyst that is safe for fireplaces, stoves (wood, pellet, coal) and stoves with catalytic combustors. It helps prevent excess ash buildup in pellet appliances. Easy to use; just spray the logs, pellets, or firebox before lighting. Have your chimney serviced by a qualified chimney professional on a regular basis.