R22–Older refrigerators used to use this gas, but it was being phased out since it was ozone-depleting. This gas is no longer used in modern refrigerators. 

R134A–This gas is well-liked these days since it protects the ozone layer. While R134a is a widely used refrigerant with excellent cooling properties, it is also a greenhouse gas, and efforts are underway to develop alternative refrigerants with lower global warming potential. As such, some manufacturers may choose to phase out the use of R134a in the future in favor of these alternatives. 

R404A – It was designed to replace R-502 and R-22 used in commercial refrigerator equipment for low and medium temperature ranges. Its properties make it ideal for use in display cases, refrigerated vehicles, ice makers, and other applications. 

R410A refrigerant is most commonly used in air conditioning systems, heat pumps, and refrigeration units. It can provide efficient cooling in both residential and commercial applications.