United 278 Professional Coil Cleaner puts the cleaning power of oxygen to use to keep your systems running more efficiently. Use it to clean and brighten chiller and evaporator coils. It is bleach-free, acid-free and dye-free. Yet, full of the cleaning power provided by peroxide and added oxygen that penetrates to lift away dirt, and stains quickly.  When you don't want an acid-based product, but need a low-pH to get the job done. turn to OXY PRO.