Drycleaning shops contain all elements necessary for uncontrolled fires: fuels, ignition sources, and oxygen. Potential combustible materials include furniture, garments, lint, and portions of the building. The greatest risk of fire and explosion exists if the drycleaning shop uses a petroleum-based solvent in drycleaning machines. Approximately 10 percent of drycleaning shops in the UnitedStates use these highly flammable solvents. Ignition can be triggered by a burning or smoldering cigarette, heated equipment such as a press, a frictional spark inside the solvent reclaimer cage, or even static electricity within the reclaimer.