CorrBlock™ from Cortec is a time release, biodegradable corrosion inhibitor block that is excellent for open loop recirculating cooling systems and wastewater systems. This safe-to-handle and easy-to-apply block is formulated with renewable soybean-based wax and Vapor phase Corrosion Inhibitor (VpCI®) technology. Immersed in water, CorrBlock™ slowly dissolves and releases calculated inhibitor amounts that protect systems from corrosion. VpCIs are excellent replacements for chromates, nitrites, and other restricted corrosion inhibitors. They form a strong monomolecular layer on metal surfaces and protect in all three phases: liquid, vapor, and interphase. CorrBlock™ is compatible with most commercially available biocides and antiscalants.