What are A2L refrigerants?

A2L refrigerants are non-toxic yet mildly flammable refrigerants

They include hydrofluoroolefins (HFOs) and HFO blends

The reason for their gaining popularity is they are a easy way to further reduce global warming potential of everyday refrigerants 

A = Non-Toxic

2 = Flammable

L= Low burning velocity

For example the HFO refrigerant R-1234yf is a 99% reduction in GWP compared to R-134a

Below is some of the commonly produced HFOs and the producers of them you may see being used today