Sweep's target is SOOT, which is a black or dark-colored powdery or flaky substance made up of tiny particles of carbon, ash, and other materials. It is created by the incomplete combustion of coal, wood, oil, or other fuels. SOOT is often found in chimneys, fireplaces, and other areas where fuel is burned. It can also be found in the air, especially in urban areas with high levels of air pollution.