Ice machines have been affected by the revolution in refrigerants, as have many other HVACR products and components.
For years, they ran on such CFCs as R-12 and -502. With the phaseout of those refrigerants, however, manufacturers moved to a variety of interim HCFC blends. At first, those blends were identified by manufacturer nomenclature (i.e., MP39, HP80, and HP81), but then they became identified by ASHRAE designations (R-401A, -402A, and -402B). R-401A is a mix of R-22, -152a, and -124; the latter two each have R-125, -290, and -22 in slightly different percentages.