R422B (also known as ISCEON® MO29) is a non-ozone-depleting HFC-based refrigerant blend designed to replace R22 (HCFC-22) in existing air conditioning and refrigeration systems — especially medium- and low-temperature applications.

It’s used as a “drop-in” or retrofit refrigerant that allows continued operation of R22 systems without major equipment modifications, though some adjustments (like lubricant change) are recommended.