CO2 AS REFRIGERANT
Using CO2 (R744) as a refrigerant is neither toxic nor flammable. CO2 has made it possible to move the lower limit of the temperature in refrigeration systems without increasing energy consumption.
Carbon dioxide (CO2) is in itself not destructive to the ozone layer. It is chemically very stable and is only harmful to our health in very large doses. It is also a very inexpensive refrigerant and thus there is no need for special measures related to the recycling and disposal of the gas.
Seawell, Hirtshals: New CO2 freezes delivered and installed.