Honeywell’s guidelines outlined in this publication to help retrofit existing R-22, R-402A, R-404A, and R-408A medium and low-temperature refrigeration systems to R-448A. *For R-507A retrofits use information cited for R-404A R-22 is an HCFC refrigerant and is regulated under the Clean Air Act. PREFACE HCFC/HFC to HFO Blend Retrofit Guidelines 3