Which refrigerant is classified as a "greenhouse gas"?

The correct choice for identifying a refrigerant classified as a "greenhouse gas" is HFCs, including R-134a. Hydrofluorocarbons (HFCs) are a group of synthetic refrigerants known to have a significant global warming potential (GWP). This means they have the ability to trap heat in the atmosphere, contributing to climate change when they are released through leaks or during the servicing of refrigeration systems.

R-134a, a commonly used HFC, despite being less harmful than older refrigerants like R-12 and R-22 in terms of ozone depletion, still poses a risk due to its greenhouse effects. This recognition has prompted regulatory bodies to implement restrictions on HFCs in many regions to mitigate their impact on global warming and encourage the transition to more environmentally friendly alternatives.

In contrast, R-12 and R-22 are classified under categories that are known for ozone depletion rather than being identified primarily as greenhouse gases, although they also have some warming potential. HCFCs, like R-22, are less harmful to the ozone layer compared to CFCs but are still not considered "greenhouse gases" in the same context as HFCs. Thus, HFCs and their variants represent