Environment Agency
Carbon dioxide (CO2) equivalent is a measure of how much a gas contributes to global warming, relative to carbon dioxide.
You calculate the carbon dioxide equivalent of a quantity of fluorinated greenhouse gases (F gas) by multiplying the mass of the gas (in metric tonnes), by the gas global warming potential (GWP).
Youll usually find the mass of an F gas expressed in kilograms (kg) on product labels. To convert the mass to metric tonnes, divide by 1,000.
See global warming potentials for F gases in the table of F gases.
Example calculation
The amount in tonnes of CO2 equivalent is the mass (in metric tonnes) of F gas multiplied by the GWP of that F gas.
For example the global warming potential of HFC 404A is 3,922. Therefore the tonnes CO2 equivalent of 10kg of hydrofluorocarbon (HFC) 404a is calculated as follows:
- Mass (in metric tonnes) of F gas multiplied by GWP of F gas
- = (10/1,000) * 3,922
- = 39.2 tonnes CO2 equivalent
Table of CO2 equivalent thresholds for common F gases
For some common F gases, this table lists:
- global warming potentials
- the quantities that are equivalent to CO2 size thresholds
| F gas | global warming potential | mass, in kg, equal to 5 tonnes CO2 (annual leak check threshold) | mass, in kg, equal to 40 tonnes CO2 (service ban threshold) | mass, in kg, equal to 50 tonnes CO2 (6-month leak check threshold) | mass, in kg, equal to 500 tonnes CO2 (3-month leak check threshold where no leakage detection system) |
|---|---|---|---|---|---|
| SF6 | 22,800 | 0.2 | 1.8 | 2.2 | 22 |
| HFC 23 | 14,800 | 0.3 | 2.7 | 3.4 | 34 |
| HFC 508B | 13,396 | 0.4 | 3.0 | 3.7 | 37 |
| HFC 143a | 4,470 | 1.1 | 8.9 | 11.2 | 112 |
| HFC 507A | 3,985 | 1.3 | 10.0 | 12.5 | 125 |
| HFC 404A | 3,922 | 1.3 | 10.2 | 12.7 | 127 |
| HFC 428A | 3,607 | 1.4 | 11.1 | 13.8 | 139 |
| HFC 125 | 3,500 | 1.4 | 11.4 | 14.3 | 143 |
| HFC 434A | 3,245 | 1.5 | 12.3 | 15.4 | 154 |
| HFC 227ea | 3,220 | 1.6 | 12.4 | 15.5 | 155 |
| HFC 422A | 3,143 | 1.6 | 12.7 | 15.9 | 159 |
| HFC 422D | 2,729 | 1.8 | 14.7 | 18.3 | 183 |
| HFC 417A | 2,346 | 2.1 | 17.1 | 21.3 | 213 |
| HFC 423A | 2,280 | 2.2 | 17.5 | 21.9 | 219 |
| HFC 438A | 2,264 | 2.2 | 17.7 | 22.1 | 221 |
| HFC 427A | 2,138 | 2.3 | 18.7 | 23.4 | 234 |
| HFC 407A | 2,107 | 2.4 | 19.0 | 23.7 | 237 |
| HFC 410A | 2,088 | 2.4 | 19.2 | 23.9 | 239 |
| HFC 442A | 1,888 | 2.6 | 21.2 | 26.5 | 265 |
| HFC 407F | 1,825 | 2.7 | 21.9 | 27.4 | 274 |
| HFC 437A | 1,805 | 2.8 | 22.2 | 27.7 | 277 |
| HFC 407C | 1,774 | 2.8 | 22.5 | 28.2 | 282 |
| HFC 426A | 1,508 | 3.3 | 26.5 | 33.2 | 332 |
| HFC 134a | 1,430 | 3.5 | 28.0 | 35.0 | 350 |
| HFC 245fa | 1,030 | 4.9 | 38.8 | 48.5 | 485 |
| HFC 365mfc | 794 | 6.3 | 50.4 | 63.0 | 630 |
| HFC 32 | 675 | 7.4 | 74.1 | 74.1 | 741 |
| HFC 152a | 124 | 40.3 | 322.6 | 403.2 | 4,032 |
Last updated 20 February 2023 +show all updates
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Added 'metric' to metric tonnes for clarification. Added further detail to the column headers in the Table of CO2 equivalent thresholds for common F gases.
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First published.