The following list summarizes the most common closed loop corrosion inhibitors on the market:

Nitrite Based Inhibitors These products utilize Nitrite to provide the mechanism for corrosion control for mixed metallurgy systems. All the components necessary for complete system protection make these products an economical choice for use in both hot water and chilled water applications.
 
Molybdate Based Inhibitors  Molybdate is the main component that provides primary corrosion control. These products provide improved corrosion control under static conditions, are less abrasive to pump seals because of the lower solids contribution to the treated solution, and offer reduced potential for microbiological activity.
 
All-Organic Inhibitors These blended inhibitors can replace typical nitrite and molybdate based treatment programs. For applications where there is no potential for food or beverage contact, our formulations will include azoles for yellow metal protection and dispersants for improved deposit control. Food Grade organic inhibitors are recommended for use with Food Grade Propylene Glycol when there is a potential for beverage or food contact. All-Organic inhibitors provide additional environmental benefits and are an effective replacement for nitrite or molybdate based programs.
 
Yellow Metal Protectors These supplements are used to control copper and copper alloy corrosion. Yellow metal inhibitors are built into many of our formulations, however, some severe service systems will require additional corrosion control specifically directed at copper and copper alloys. Especially useful in all copper or copper alloy systems where a low solids treatment is required.