Fluorocarbons: Designation and Safety Classification of Refrigerants

Designation of Refrigerants

The basis of the designation of the refrigerants fluids is based on a numbering system

Pure Fluorocarbons (HFC) refrigerants and their blends

The refrigerants are numbered with an R-, followed by the HFC-number, given by the rules of the fluorocarbons numbering system.

Isomers are identified with lower cases (ex R 134a).

HFC refrigerant blends (i.e. mixtures of pure refrigerants), are numbered after the internationally accepted ASHRAE nomenclature.

Blends having the same pure components but with different compositions are identified with upper cases (ex R 404A). Refrigerants having the form R-4xxx are zeotropic blends of two or more refrigerants, while those with the form R-5xxx are azeotropes.

The numbers are in chronological order of the refrigerant’s approval by ASHRAE.

For the GWP of Refrigerants go to FS nr18: Selecting and Using GWP values for Refrigerants

Designation and safety classification of refrigerants
TypeProfileApplication
R-134a Replace R-12 in most applications. Good performance in medium temperature applications ; household refrigerators; car air conditioning systems; heat pumps; chillers; transport refrigeration; commercial cooling.
R-245fa Replacement of R-123. Chillers, heat transfer fluid.
R-404A Near azeotropic refrigerant containing R-125, R-143a and R-134a (44/52/4% by weight). Cold-storage cells; supermarket display cases; ice machines; replacement for R-502 in transport refrigeration; retrofit of existing R-502-installations R-407A Zeotropic refrigerant containing R-32, R-125 and R-134a (20/40/40 weight-%). Close replacement of R-22 in commercial refrigeration applications. Possible replacement for R-404A in supermarket chill and low temperature systems.
R-407C Zeotropic refrigerant containing R-32, R-125 and R-134a (23/25/52 weight-%). New air-conditioning units or replacement for R-22 in existing installations; heat-pumps; industrial and commercial cooling. R-407F Zeotropic refrigerant containing R-32, R-125 and R-134a (30/30/40 weight-%). Close replacement of R-22 in commercial refrigeration applications. Possible replacement for R-404A in supermarket medium and low temperature systems.
 R-407F Zeotropic refrigrant containing R-32, R-125 and R_134a (30/30/40 weight-%). Close replacement of R-22 in commercial refrigeration applications. Possible replacement for R-404-A in supermarket medium and low temperature systems
R-410A Near azeotropic refrigerant containing R-32 and R-125 (50/50 by weight). Substitute for R-22 ; air-conditioning units; heat pumps; cold storage; industrial and commercial refrigeration; substitution of R-13B1 in low temperature application.
R-417B Contains R-125, R-134a and Butane R-600 (79/18.25/2.75 weight-%). R-22 substitute.
R-422A Contains R-125, R-134a and Isobutane R-600a (85.1/11.5/3.4 weight-%). R404A replacement very similar properties; R502 retrofit refrigerant.
R-422D Contains R-125, R-134a and Isobutane R-600a (65.1/31.5/3.4 weight-%). R-22 substitue.
R-427A Contains R-32, R-125, R-134a and R-143a (15/25/50/10 weight-%). R-22 subsitute.
R-507 Azeotropic refrigerant containing R-125 and R-143a (50/50% by weight). Cold-storage cells; supermarket display cases; ice machines; replacement for R-502 in refrigerated transport; replacement for R-502; retrofit of existing R-502-installations.
R-1234yf Low GPW replacement of R-134a Mobile air-conditioning, plug in appliances.

Miscellaneous organic compounds

Organic compounds are numbered with the same system as Fluorocarbons.

Example :

Propane C3H8 (R-290)
Nb of C atoms is X = 3
Nb of H atoms is Y = 8
Nb of F atoms is Z = 0
Substract 90 from 380 = 290

Inorganic compounds

Inorganic compounds shall be assigned a number in the 700 series, identification numbers are formed by adding the relative molecular mass of components to 700.

Examples:

R717 = ammonia (molecular mass 17)
R718 = water (molecular mass 18)
R744 = CO2 (molecular mass 44)

Safety classification of refrigerants

The safety classification consists of two alphanumeric characters (e.g. A2); the capital letter corresponds to toxicity and the digit to flammability.

Toxicity classification

Refrigerants are divided into two groups according to toxicity:

  • Class A signifies refrigerants for which toxicity has not been identified at concentrations less than or equal to 400 ppm
  • Class B signifies refrigerants for which there is evidence of toxicity at concentrations below 400 ppm

Flammability classification

Refrigerants are divided into three groups according to flammability:

  • Class 1 indicates refrigerants that do not show flame propagation when tested in air at 21°C and 101 kPa
  • Class 2 indicates refrigerants having a lower flammability limit of more than 0.10 kg/m3 at 21°C and 101 kPa and a heat of combustion of less than 19 kJ/kg
  • Class 3 indicates refrigerants that are highly flammable as defined by a lower flammability limit of less than or equal to 0.10 kg/m3 at 21°C and 101 kPa or a heat of combustion greater than or equal to 19 kJ/kg

Mixtures

Mixtures, whether zeotropic or azeotropic, with flammability and/or toxicity characteristics which may change as the composition changes during fractionation, shall be assigned a safety group classification based on the worst case of fractionation.

Example:

R404A is classified A1

Classification of main refrigerants 
Refrigerant NumberNameComposition or chemical formula
(mass percentage)
Safety classification
Inorganic Compound
R-717 ammonia NH3 B2
R-718 water H2O A1
R-744 carbon dioxide CO2 A1
Organic Compound
Hydrocarbons
R-290 propane CH3CH2CH3 A3
R-600 butane CH3CH2 CH2CH3 A3
R-600a isobutane CH(CH3)2CH3 A3
R-1270 propylene CH3CH=CH2 A3
Hydrofluorocarbons (HFCs)
R-32 difluoromethane CH2F2 A2
R-125 pentafluoroethane CHF2CF3 A1
R-134a 1,1,1,2-tetrafluoroethane CH2FCF3 A1
R-143a 1,1,1-trifluoroethane CH3CF3 A2
R-152a 1,1-difluoroethane CH3CHF2 A2
Azeotropic mixtures
R-502   R22/R115 (48.8/51.2) A1
R-507   R125/R143a (50/50) A1
Zeotropic mixtures
R-404A   R125/R143a/R134a (44/52/4) A1
R-407C   R32/R125/R134a (23/25/52) A1
R-410A   R32/R125 (50/50) A1