People who restore art are a cautious group. They are particular and precise. They have to be. One mistake while attempting to clean up and restore a work of art to its original beauty can permanently damage it. Not only do they often work on fragile paintings and prints that can be hundreds of years old, but they work with art that can be extremely valuable! It's easy to understand why art restorers are cautious. So if they adopt new methods to their craft, it says a lot about that method.
However, who would have guessed that a new method would come from space research … in the form of atomic oxygen? Atomic oxygen makes up about 96% of the atmosphere where the ISS orbits the Earth. In that part of the atmosphere, the ultraviolet (UV) radiation from the sun breaks up O2 molecules (the kind of oxygen we breath) into separate oxygen atoms (O1), known as atomic oxygen.
On Earth, O2 oxygen contributes to corrosion, such as rust. In space, atomic oxygen is incredibly corrosive. The constant exposure to atomic oxygen is hard on the outer surfaces of the ISS and other spacecraft like satellites, which can shorten their life spans. To better protect the ISS, scientists needed to study and better understand atomic oxygen.
While developing methods to prevent damage from atomic oxygen on different surfaces like the exterior of the ISS, researchers discovered that atomic oxygen could also remove layers of soot and many other materials from a surface. Additionally, they figured out that atomic oxygen will NOT react with most paints because the substances used to create the color in the paints (pigments) are unaffected by atomic oxygen. But what about the paints with pigment that does react to atomic oxygen? Well, as part of their research, scientists determined that you can control the application of atomic oxygen so it removes only the substances you want while leaving the paint intact!
So done correctly, using atomic oxygen can work on essentially any painting. And of course, every day every painting in the world gets one day older and one day dirtier. There are a lot of paintings out there! However, one day older doesn't typically make that big a difference, does it? Yet, every day somewhere in the world, an art collection or an art gallery suffers fire damage. Even for those works of art that are spared from catching fire, the smoke and soot can ruin them. That is, without some sort of effort to remove the soot and restore them!
Art restoration has been going on probably as long as paintings have been damaged by fire! Cleaning solvents have been the main method for trying to restore paints to their original colors and overall look. Art restorers carefully apply a cleansing agent to a painting in ways designed to remove whatever was not part of the original painting while leaving the original paints alone. Sometimes, it works well. Sometimes, it can't completely remove the stains. Sometimes, it removes more than it should!
And every time, a cleaning solvent will release gases (or vapors) in the air. (What you smell are some of the vapors.) Generally, the stronger the solvent, the stronger and more environmentally damaging its gases are. Those who work with the stronger solvents use them sparingly and often wear protective gear for their breathing. Atomic oxygen, on the other hand, is much more environmentally friendly in the art restoration process. Only trace amounts of ozone (O3), carbon monoxide, and carbon dioxide are produced during the formation of atomic oxygen and during its reaction with the substances on a painting.
Still, art restorers aren't necessarily going to change methods because they're more "green." One key moment in proving atomic oxygen's unique ability was with a painting by pop artist Andy Warhol. The Carnegie Museum of Art in Pittsburgh owns Warhol's painting called "Bathtub" from 1961. Someone kissed the painting with bright red lipstick. The museum feared that trying to remove the lipstick with solvents would make the stain worse. Instead, scientists applied some atomic oxygen, and voila … it completely removed the lipstick! Now it looks like it won't be long until art restorers talk about the days when the old timers used solvents instead of atomic oxygen.