R600a (Iso-Butane) is refrigerant grade Iso-Butane used as a replacement for R12 and R134a in a variety of high temperature refrigeration applications. R600a (Iso-Butane) is a hydrocarbon that is becoming increasingly popular due to its low Global Warming Potential (GWP). It is the refrigerant of choice for domestic and light commercial refrigeration units, including fridges and freezers, drink dispensers and stand alone display units.