What Does Sulfur Dioxide (SO2) Mean?
Sulfur dioxide (chemical formula SO2) is a colorless gas with a strong, pungent odor. It is highly reactive and is capable of combining with other compounds to form toxic products such as sulfuric acid and sulfurous acid. The vast majority (close to 99%) of sulfur dioxide originates from human activity, specifically, industrial activities that process materials containing sulfur. Sulfur dioxide can contribute to the corrosion process.
Corrosionpedia Explains Sulfur Dioxide (SO2)
Sulfur dioxide is known for its aggressiveness towards steel and other metal alloys. While the compound in its pure form does not react strongly with metal, it can be highly corrosive when exposed to the atmosphere. When sulfur dioxide reacts with moisture (water) and oxygen, sulfuric acid is formed.
This acidic compound is highly corrosive and can result in the accelerated deterioration of steel infrastructures. The sulfate ions formed on the surface of the moisture layer is considered to be the main contributor to accelerated corrosion on metallic surfaces.