Toxic Corrosion is Soviet Line 2 Top Secret Protocol in Command & Conquer: Red Alert 3. By selecting a friendly unit, that unit can be contaminated with Toxins, causing it to be consistently damaged, and spread a toxic mess on the ground or sea. If the contaminated unit is destroyed, it will spread a cloud of toxins, contaminating a sizable radius. The effect can be removed by repair drones or the Repair Multigunner IFV.
Strangely, toxin created by this protocol does not clear garrisoned structures.
