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.
LFL = Lower Flammability Limit
ETFL60 = Elevated Temperature Flame Limit @ 60 °C
HOC = Heat Of Combustion
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.