Until recently, the Large Hadron Collider at CERN, the multi-billion pound project to study particle physics, was using HFCs for refrigeration purposes. But starting 2019, the scientists started looking for greener options.
It was recently announced that the future experiments with the Large Hadron Collider (LHC), will employ CO2 refrigeration technology.
Following the implementation of the F-gas regulations, CERN, the operators of the LHC, took the decision to transition to move away from HFCs. While it is common for ultra-low temperature applications to use blends of R744 with other “natural” hydrocarbon refrigerants like ethane and ethylene, this was ruled out due to their flammability.
https://www.coolingpost.com/world-news/large-hadron-collider-moves-to-co2-refrigeration/