Chemical refrigerants are assigned an R number which is determined systematically according to molecular structure. Common refrigerants are frequently referred to as Freon (a registered trademark of DuPont). The following is a list of refrigerants with their Type/Prefix, ASHRAE designated numbers, IUPAC chemical name, molecular formula, CAS registry number / Blend Name, Atmospheric Lifetime in years, Semi-Empirical Ozone depletion potential, net Global warming potential over a 100-year time horizon, Occupational exposure limit/Permissible exposure limit in parts per million (volume per volume) over a time-weighted average (TWA) concentration for a normal eight-hour work day and a 40-hour work week, ASHRAE 34 Safety Group in Toxicity & Flammability (in Air @ 60 °C & 101.3 kPa) classing, Refrigerant Concentration Limit / Immediately Dangerous to Life or Health in parts per million (volume per volume) & grams per cubic meter, Molecular mass in Atomic mass units, Normal Boiling Point (or Bubble & Dew Points for the Zeotrope(400)-series)(or Normal Boiling Point & Azeotropic Temperature for the Azeotrope(500)-series) at 101,325 Pa (1 atmosphere) in degrees Celsius, Critical Temperature in degrees Celsius and Critical Pressure (absolute) in kiloPascals.
Type and flammability
Compounds used as refrigerants may be described using either the appropriate prefix above or with the prefixes "R-" or "Refrigerant." Thus, CFC-12 may also be written as R-12 or Refrigerant 12.
An alkene, olefin, or olefine is an unsaturated chemical compound containing at least one carbon-to-carbon double bond.