The smoke residue, which remains after a fire, consists of particles that were not completely vaporized by the heat of the burning process. The particles deposit on the surfaces of walls and furnishings but usually do no penetrate below the surface to s significant degree. The composition of smoke residue varies, depending on the substances burned and the heat characteristics of the fire. Smoldering, or oxygen-starved fires tend to burn at lower temperatures and results in more residue than fast burning fires for example. Because most smoke residue is strongly acidic, it can tarnish metal surfaces and trim and cause rust on exposed ferrous metals.

Clothing and fabrics may also suffer color changes as a result of smoke residue, and certain types of smoke can permanently affect wood furniture finishes. Once the smoke residue has been completely removed all chemical action from the smoke is halted. However the full extent of smoke damage often cannot be observed until after cleaning.

The remedy of smoke damage is largely an effort to remove the smoke particles without causing them to be absorbed into the surface. This may involve a two or three stage cleaning procedure. For this reason smoke "cleaning" differs significantly from ordinary cleaning methods.

Fire victims are sometimes concerned about the possible toxic effects of smoke. While exposed food items directly affected by smoke or heat should be discarded, proper cleaning techniques can remove smoke residues and leave furnishings in a wholesome condition for continued use. Highly toxic residues, while receiving extravagant coverage in the press, are extremely rare.