Update on New Refrigerants Designations and Safety Classifications

This document is a fact sheet summarizes how the American Society of Heating, Refrigerating and Air-Conditioning Engineers Standard 34 assigns refrigerant designations and safety classifications. It explains the reference numbering system for single substances and blends, including distinctions between zeotropic and azeotropic blends and the use of suffix letters. It describes the safety group method based on toxicity and flammability and notes recent updates to the classification approach. The fact sheet then provides tabulated information for many refrigerants and refrigerant blends, listing identifiers, chemical components, safety group, global warming potential values, and key thermodynamic data such as boiling points and temperature glide.