Soot and Smoke Residue
What is in the Smoke Residue/Soot? All materials involved in a fire cause odors. Typically, soot is representative of what has burned, but may include byproducts that at first seem unrelated to the original material. For example, hydrogen cyanide is a byproduct of burning wool. When wood burns it can produce manganese and benzene. As many products as there are in the world, there are an equal number of byproducts produced in a fire. Each fire is different based on the contents of what has burned during the event. Organic and inorganic materials produce different types of smoke residue or soot. These residues may be present on surfaces that conservators may be tasked with treating. Burnt organic material produces soot that is hard to see and often has a very pungent odor. This is known as protein smoke. It can discolor paints and varnishes. Protein smoke can disperse over large areas and attach itself to everything. How the fire burns and how much moisture is in the air while the fire burns, plays a role in soot deposition on articles. The amount of moisture in the air is a key component in whether the smoke that is produced is wet or dry. There are several types of smoke or soot, which may be present on a surface that conservators might be tasked with treating: Wet Smoke—can present as a sticky residue or soot, and is often associated with a smoldering type of fire and often will have a strong odor. Dry Smoke—associated with a fast-burning fire and occurs at high temperatures. Protein—often present in soot, usually invisible, it can discolor paints and varnishes and often has a very pungent odor. Protein odors could be caused by food on the stove burning slowly or other sources. The slow burn allows the protein to disperse and attach itself to everything, producing a strong odor.