For use in drilling mud to control bacterial slime contamination due to the presence of iron-related and sulphate reducing bacteria. It is a combined liquid biocide and corrosion inhibitor for most water-based systems. It is water soluble oil dispersible. When biological growth occurs in fluid the organisms can be killed with a treatment of Biocide. As a pretreatment, the product is used in drilling fluid which will be left in the hole for an extended period.