Which refrigerant is typically used in Thermo King systems?

In Thermo King systems, the refrigerant typically used is R-134a. This refrigerant is favored for its efficiency and lower environmental impact compared to older refrigerants. R-12, while once commonly used, has been phased out due to its ozone-depleting properties. R-22 is also being gradually retired due to similar concerns regarding its environmental safety. R-410A is mainly used in residential and commercial air conditioning systems and is not generally found in transport refrigeration like that provided by Thermo King. R-134a, on the other hand, offers a suitable alternative with effective refrigeration capabilities and complies with modern environmental regulations, making it the preferred choice in these systems.