What gas is used in freezers and fridges?

Fridges used to use a gas called Chloro-Flouro-Carbon or CFC, but the newer models tend to avoid these due to them being harmful to the atmosphere. Instead, your fridge probably uses another type of gas called HFC-134a, which becomes a liquid at - 26.6 degrees Celsius.

HFC-134a = answer

Chloro-Flouro-Carbon

Explanation:

Chloro-Flouro-Carbon (CFC Gas) is used as a refrigerant in fridges and freezers.