Halogen free (natural) refrigerants

Alternatives for HCFC and HFC refrigerants (halogen free refrigerants) (status as of 09.2020)
①: flammable
②: toxic
③: large deviation in refrigerating capacity and pressures to the previous refrigerant
Current Refrigerants	Alternatives
	ASHRAE Classification	Trade Name	Formula	Detailed Information
R134a	R290/600a①	-	C₃H₈/C₄H₁₀	R290 (Propane) as alternative refrigerant
R134a	R600a①③	-	C₄H₁₀	R290 (Propane) as alternative refrigerant
R404A R507A R22	R717①②	-	NH₃	NH₃ (Ammonia) as alternative refrigerant
	R723①②	-	NH₃ + R-E170	R723 (NH₃/DME) as an alternative to NH₃
	R290①	-	C₃H₈	R290 (Propane) as alternative refrigerant
	R1270①	-	C₃H₆	Propylene (R1270) as an alternative to propane
R124	R600a①	-	C₄H₁₀	R124 and R142b as substitutes for R114 and R12B1
R410A	no direct alternatives available
R23	R170①	-	C₂H₆	Alternatives for R13 and R503
Various	R744③	-	CO₂	Carbon dioxide R744 (CO₂) as an alternative refrigerant and secondary fluid