Also, immersion of the surface or swabbing during solvent cleaning may move or remove pigment through mechanical contact, especially if the fire damage extends into the paint binder. A noncontact technique of removing organic deposits from surfaces was developed out of NASA research on the effects of oxygen atoms on various materials. Atomic oxygen is present in the atmosphere surrounding the Earth at the altitudes where satellites typically orbit. It can react chemically with surface coatings or deposits that contain carbon. In the reaction, the carbon is converted to carbon monoxide and some carbon dioxide.
Water vapor is also a byproduct of the reaction if the surface contains carbon-hydrogen bonds.
To study this reaction, NASA developed Earth-based facilities to produce atomic oxygen for material exposure and testing. The left photo shows a painting that was damaged in an arson fire. The right photo shows the same painting after it was cleaned with atomic oxygen. Because cleaning with atomic oxygen is a dry process, there is less risk of the paint surface leaching out or swelling. In addition, because the atomic oxygen reaction is confined to the surface, risk to the underlying paint or canvas is minimized.