COOLCLEAR 600 is a corrosion inhibitor designed for closed loop, recirculating water systems. This nitrite-based formulation was specifically designed to offer maximum protection for closed loop systems which include chilled water systems, hot water systems and diesel engine jackets. It is used internationally for the protection of diesel engine cooling systems. The product contains nitrite for improved corrosion protection, silica and borates as corrosion inhibitors, and indicator for easy product identification in the system.it is easily monitored and controlled.