Biosperse CN7539 is a blend of BNPD and isothiazolinones. It is very effective at controlling the anaerobic sulfate reducing bacteria (SRB) that are responsible for causing microbiologically induced corrosion as well as generating gases such as H2S. The actives react with thiol containing enzymes, resulting in inhibition of respiration and metabolism. Additionally, the BNPD damages components of the electron transport chain, which leads to the generation of peroxides and oxidizing radicals. Repair mechanisms within the microbial cell are also disabled.