What is Microbiologically Influenced Corrosion (MIC)?
Microbiologically Influenced Corrosion (MIC) is a type of corrosion which is initiated by microbiological life forms and occurs often in fire sprinkler systems. Certain species of bacterium aid in the corrosion cell creation and propagation of the corrosion process. There are three main groups of bacteria which are responsible for MIC, each group is named after its specific function on metallic surfaces: 1. Acid Producing Bacteria (APB): This group is comprised of bacteria which actually create organic and inorganic acids (acetic acid, hydrochloric acid, sulfuric acid, etc.) as a waste product in their function. The created acid is very corrosive to metallic surfaces. They are mainly anaerobic (do not need oxygen to function). They are responsible for localized corrosion and pit formation. 2. Sulfur Reducing Bacteria (SRB): This group is comprised of bacteria which reduce available sulfur and react with iron on metallic surfaces to form iron sulfide and hydrogen sulfide gas, as waste p
