Refrigerant & F-Gas GWP Values
Refrigerant leakage is one of the highest-leverage lines in a greenhouse-gas inventory. A single kilogram of R-404A vented to atmosphere is worth 4,728 kg CO₂e — the same as burning roughly two tonnes of diesel. Which global warming potential you apply, and whether you count blends and legacy CFCs correctly, can swing a facility's Scope 1 total by orders of magnitude.
This page publishes the complete set of refrigerant and fluorinated-gas GWP-100 values in the GreenCalculus MasterBrain v2026.284 — 51 substances spanning CFCs, HCFCs, HFCs, HFC and HFO blends, PFCs and natural refrigerants. Values are on the IPCC AR6 basis, with EU F-Gas Regulation (EU) 2024/573 defaults for substances not yet characterised in an IPCC assessment.
Refrigerant emissions are Scope 1 fugitive: kg CO2e = mass leaked × GWP-100. Common AR6 values: R-134a 1,530, R-410A 2,256, R-404A 4,728, R-32 771, R-1234yf 0.501, ammonia 0. The lowest are natural refrigerants (ammonia and water 0, propane 0.02) and HFOs. In new US air-conditioners R-410A has been replaced by R-32 and R-454B (531 on AR6), which are below the US limit of 700; on EPA’s own values the three are 2,088, 675 and 465.
Refrigerant GWP & Scope 1 fugitive emissions
When refrigerant escapes from a chiller, air-conditioner, heat pump or refrigeration system — through seals, joints, servicing losses or at end of life — the fluorinated gas itself is a potent greenhouse gas. These are direct, Scope 1 fugitive emissions, entirely separate from the indirect Scope 2 emissions of the electricity that runs the equipment. The global warming potential converts each kilogram leaked into a CO₂-equivalent figure.
Every value on this page is a GWP-100 (100-year) figure — the horizon required by corporate GHG reporting. For substances characterised by the IPCC, GreenCalculus uses the latest assessment, AR6 (2021); where the IPCC has not yet published a value, the dataset falls back to the default in the EU F-Gas Regulation. AR6, AR5 and AR4 give materially different numbers for many HFCs, so the basis must always be disclosed. These are the values for greenhouse-gas inventory reporting; regulatory F-Gas quota compliance uses the Regulation's own Annex values, which can differ.
Which refrigerant has the lowest GWP?
The lowest-GWP refrigerants are the natural refrigerants: ammonia (R-717) and water (R-718) have a GWP of 0, the hydrocarbons isobutane (R-600a) and propane (R-290) are well below 1, and carbon dioxide (R-744) is 1 by definition. Among synthetic refrigerants, the HFOs come lowest, with R-1234yf at 0.501. For comparison, the common HFCs they replace run from R-32 at 771 to R-404A at 4,728.
| Refrigerant | GWP-100 | Safety class | Typical use |
|---|---|---|---|
| R-717 (ammonia) | 0 | B2L (toxic, lower flammability) | Industrial refrigeration, cold stores |
| R-718 (water) | 0 | A1 | Absorption and some industrial chillers |
| R-600a (isobutane) | 0.006 | A3 (highly flammable) | Domestic fridges and freezers |
| R-290 (propane) | 0.02 | A3 (highly flammable) | Heat pumps, room AC, small commercial refrigeration |
| R-1234yf | 0.501 | A2L (mildly flammable) | Car air-conditioning |
| R-744 (CO₂) | 1 | A1 | Supermarkets, heat-pump water heaters, some vehicles |
| R-1234ze(E) | 1.37 | A2L | Chillers |
| R-1336mzz(Z) | 2 | A1 | Centrifugal chillers, high-temperature heat pumps |
| R-1233zd(E) | 4 | A1 | Centrifugal chillers |
GWP values are the dataset’s IPCC AR6 GWP-100 figures (see the tables below). Safety classes are ASHRAE 34 designations: A = lower toxicity, B = higher toxicity; 1 = no flame propagation, 2L = lower flammability, 3 = higher flammability.
The lowest GWP is not the only test. Hydrocarbons are highly flammable, so charge sizes are limited; ammonia is toxic and suits plant rooms rather than homes; CO₂ runs at very high pressures; and HFOs such as R-1234yf break down in the atmosphere to trifluoroacetic acid (TFA), a persistent substance that regulators are examining. In practice the choice is the lowest-GWP refrigerant that is safe and efficient for the application.
What the rules push towards
| Equipment | Rule | Limit | From |
|---|---|---|---|
| Car air-conditioning (new vehicles) | EU Directive 2006/40/EC | No F-gases above GWP 150 | 1 Jan 2017 |
| Domestic fridges and freezers | EU Regulation 2024/573 | No fluorinated gases (safety exceptions) | 1 Jan 2026 |
| Self-contained commercial refrigeration | EU Regulation 2024/573 | Below GWP 150 | 1 Jan 2025 |
| Self-contained AC and heat pumps up to 12 kW | EU Regulation 2024/573 | Below GWP 150 (safety exceptions up to 750) | 1 Jan 2027 |
| Split air-to-air systems up to 12 kW | EU Regulation 2024/573 | Below GWP 150; no F-gases from 2035 | 1 Jan 2029 |
| Residential and light-commercial AC and heat pumps | US EPA Technology Transitions rule (AIM Act) | Below GWP 700 | Made or imported from 1 Jan 2025 |
EU dates from the Official Journal texts (Directive 2006/40/EC Article 5; Regulation (EU) 2024/573 Annex IV). The US limit is from EPA’s 2023 Technology Transitions rule; a final rule of 26 May 2026 removed the installation deadline for systems made or imported before 2025. Each rule measures GWP on its own basis: US limits use the AIM Act’s exchange values, on which R-32 is 675, while on AR6 it is 771.
R-410A, R-32 and R-454B: the US switch
New central air-conditioners and heat pumps in the US no longer use R-410A. Since 1 January 2025, new residential and light-commercial systems must use a refrigerant with a global warming potential below 700, and the main replacements are R-32 and R-454B. Both are below that limit; R-410A is three times over it.
| Refrigerant | EPA value | IPCC AR6 | Safety class |
|---|---|---|---|
| R-410A R-32 and R-125, 50/50; the old standard |
2,088 | 2,256 | A1 |
| R-32 a single HFC |
675 | 771 | A2L (mildly flammable) |
| R-454B R-32 68.9% and the HFO R-1234yf 31.1% |
465 | 531 | A2L (mildly flammable) |
EPA values: EPA’s Technology Transitions GWP reference table (last updated 2 April 2026), which uses the IPCC 2007 (AR4) values for single HFCs and calculates blends from them. AR6 values: this dataset. Safety classes are ASHRAE 34 designations.
Why two numbers. US rules measure GWP on the values in EPA’s Technology Transitions table, based on IPCC 2007 (AR4), so R-454B is 465 for the 700 limit. Greenhouse-gas inventories now use AR6, on which the same gas is 531. Use the EPA value to check whether equipment meets the US limit, and the AR6 value to report a leak. Our section on why one refrigerant has five numbers explains the differences.
What a leak is worth. On AR6, a kilogram of R-410A leaked counts as 2,256 kg CO₂e, a kilogram of R-32 as 771 (66% less) and a kilogram of R-454B as 531 (76% less). The refrigerant leakage calculator works out a system’s emissions from its charge and leak rate.
Pressures. For the pressure of each gas at each temperature, with a superheat and subcooling lookup, see the R-410A, R-32 and R-454B PT charts. The refrigerant PT chart page compares eight refrigerants side by side.
The dates
- 1 January 2024: US production and imports of HFCs, R-410A among them, were cut to 60% of the baseline under the AIM Act. They fall to 30% in 2029, 20% in 2034 and 15% from 2036.
- 1 January 2025: new self-contained AC and heat pump products, and new split systems, must use a refrigerant below GWP 700 (40 CFR 84.54).
- 1 January 2026: the same limit for variable refrigerant flow (VRF) systems, with installation allowed until 1 January 2027 where all components were made or imported before 2026.
- 27 July 2026: EPA removed the deadline for installing split systems whose components were all made or imported before 1 January 2025, so remaining R-410A stock can still be installed. Until then the deadline was 1 January 2026.
If you have an R-410A system
You do not have to replace it. The rules restrict new equipment, not existing systems, and R-410A can still be used to service and recharge them: EPA has said HFCs will remain available for servicing existing equipment. Supply is being cut under the phasedown, and EPA notes that overall HFC prices could rise as it continues, so a large leak may cost more to fix over time. When the system is replaced, the new one will use R-32 or R-454B.
Sources: 40 CFR 84.54 (as amended 26 May 2026, 91 FR 31329); EPA, Phasedown of Hydrofluorocarbons: Reconsideration of Certain Regulatory Requirements Promulgated Under the Technology Transitions Provisions, Federal Register 26 May 2026 (FR Doc. 2026-10387), effective 27 July 2026; AIM Act, 42 U.S.C. 7675(e)(2)(C); EPA Technology Transitions GWP reference table.
CFCs & HCFCs — legacy refrigerants
Chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) are ozone-depleting substances phased out under the Montreal Protocol. Their production is banned or restricted, but they remain in the inventory of legacy equipment — older chillers, automotive AC and foam — and are among the highest-GWP refrigerants in service.
| Refrigerant | Type | GWP-100 (kg CO₂e/kg) | Basis |
|---|---|---|---|
| R-12 | CFC | 12400 | IPCC AR6 |
| R-11 | CFC | 6230 | IPCC AR6 |
| R-22 | HCFC | 1960 | IPCC AR6 |
| R-141b | HCFC | 860 | IPCC AR6 |
| R-123 | HCFC | 90 | IPCC AR6 |
| HCFC-1233xf | HCFC | 1 | EU F-Gas Reg |
| HCFC-1224yd(Z) | HCFC | 0.06 | EU F-Gas Reg |
HFCs & HFC blends
Hydrofluorocarbons replaced CFCs and HCFCs and are the dominant fluorinated refrigerants today. They carry no ozone-depletion potential but high GWP, which is why the EU F-Gas Regulation and the Kigali Amendment are phasing them down. Single-component HFCs first, then the commercial blends built from them.
| Refrigerant | Type | GWP-100 (kg CO₂e/kg) | Basis |
|---|---|---|---|
| R-23 | HFC | 14600 | IPCC AR6 |
| R-236fa | HFC | 8690 | IPCC AR6 |
| R-143a | HFC | 5810 | IPCC AR6 |
| R-125 | HFC | 3740 | IPCC AR6 |
| R-227ea | HFC | 3600 | IPCC AR6 |
| R-134a | HFC | 1530 | IPCC AR6 |
| R-245fa | HFC | 962 | IPCC AR6 |
| R-32 | HFC | 771 | IPCC AR6 |
| R-152a | HFC | 164 | IPCC AR6 |
| R-41 | HFC | 135 | IPCC AR6 |
| HFC-1132(E) (trans) | HFC | 1 | EU F-Gas Reg |
| Nonafluoro-TFM-pentene | HFC | 1 | EU F-Gas Reg |
HFC blends — the workhorses of commercial and residential refrigeration and air-conditioning. Blend GWPs are the mass-weighted average of their component GWPs:
| Refrigerant | Type | GWP-100 (kg CO₂e/kg) | Basis |
|---|---|---|---|
| R-507A | HFC blend | 4775 | IPCC AR6 |
| R-404A | HFC blend | 4728 | IPCC AR6 |
| R-434A | HFC blend | 3654 | IPCC AR6 |
| R-422A | HFC blend | 3359 | IPCC AR6 |
| R-422D | HFC blend | 2917 | IPCC AR6 |
| R-417A | HFC blend | 2508 | IPCC AR6 |
| R-427A | HFC blend | 2397 | IPCC AR6 |
| R-407A | HFC blend | 2262 | IPCC AR6 |
| R-410A | HFC blend | 2256 | IPCC AR6 |
| R-407F | HFC blend | 1965 | IPCC AR6 |
| R-437A | HFC blend | 1930 | IPCC AR6 |
| R-407C | HFC blend | 1908 | IPCC AR6 |
HFOs & low-GWP blends
Hydrofluoro-olefins (HFOs) are the newest synthetic class: unsaturated fluorocarbons with atmospheric lifetimes of days rather than years, giving near-zero GWP-100. They are used pure and as the low-GWP constituent of the latest blends replacing R-134a, R-404A and R-410A.
| Refrigerant | Type | GWP-100 (kg CO₂e/kg) | Basis |
|---|---|---|---|
| R-452A | HFO blend | 2292 | IPCC AR6 |
| R-452B | HFO blend | 779 | IPCC AR6 |
| R-513A | HFO blend | 673 | IPCC AR6 |
| R-450A | HFO blend | 643 | IPCC AR6 |
| R-454B | HFO blend | 531 | IPCC AR6 |
| R-515B | HFO blend | 322 | IPCC AR6 |
| R-454A | HFO blend | 270 | IPCC AR6 |
| R-1234ze(E) | HFO | 1.37 | IPCC AR6 |
| R-1233zd(E) | HFO | 4 | IPCC AR6 |
| R-1336mzz(Z) | HFO | 2 | IPCC AR6 |
| R-1234yf | HFO | 0.501 | IPCC AR6 |
Natural refrigerants
The natural refrigerants — hydrocarbons (propane, isobutane), ammonia, carbon dioxide and water — have negligible or zero direct GWP. They are the long-term destination of the F-gas phasedown, subject to flammability and toxicity handling requirements.
| Refrigerant | Type | GWP-100 (kg CO₂e/kg) | Basis |
|---|---|---|---|
| R-744 | Carbon dioxide (CO₂) | 1 | IPCC AR6 |
| R-290 | Hydrocarbon | 0.02 | IPCC AR6 |
| R-600a | Hydrocarbon | 0.006 | IPCC AR6 |
| R-717 | Ammonia (NH₃) | 0 | IPCC AR6 |
| R-718 | Water (H₂O) | 0 | IPCC AR6 |
PFCs & other F-gases
Perfluorocarbons and fluorinated ketones that appear in the EU F-Gas Regulation Annex but are not yet characterised in an IPCC assessment. Values are the Regulation's defaults, drawn from the named literature.
| Refrigerant | Type | GWP-100 (kg CO₂e/kg) | Basis |
|---|---|---|---|
| c-C₃F₆ (PFC) | PFC | 9200 | EU F-Gas Reg |
| Perfluoro-N-methylmorpholine | PFC | 8800 | EU F-Gas Reg |
| PFC-4-1-14 | PFC | 7370 | EU F-Gas Reg |
| Perfluorobutanone (fluoroketone) | Fluoroketone | 0.29 | EU F-Gas Reg |
Basis. “IPCC AR6” values are GWP-100 from the IPCC Sixth Assessment Report (WGI, 2021); blend values are mass-weighted from AR6 component GWPs. “EU F-Gas Reg” values are the defaults published in EU Regulation (EU) 2024/573 (drawn from named literature: Tokuhashi 2018, Ren 2019, Droste 2019, WMO 2018) for substances not yet characterised in an IPCC assessment. All values are GWP-100 in kg CO₂e per kg of refrigerant leaked.
The same refrigerant, five different numbers
Every value above is IPCC AR6, 100-year. That is the current default, and it is not what every framework asks for — which matters more for refrigerants than for almost anything else in an inventory, because the numbers are in the thousands and a leak is measured in kilograms.
The blends are where this bites hardest, and they are also where it is hardest to look up: the full IPCC GWP matrix carries every pure gas across all five bases, but blends are mixtures and are not listed in the assessment reports as single entries at all. They are derived — composition from ANSI/ASHRAE Standard 34, then the mass-weighted sum of the constituent GWPs from whichever report you are working to.
| Blend | Composition (ASHRAE 34) | AR4-100 | AR5-100 | AR6-100 | AR6-20 | AR6-500 | AR5→AR6 |
|---|---|---|---|---|---|---|---|
| R-404A | R-125 / R-143a / R-134a | 3,922 | 3,943 | 4,728 | 7,208 | 1,515 | +19.9% |
| R-407A | R-32 / R-125 / R-134a | 2,107 | 1,923 | 2,262 | 4,890 | 662 | +17.6% |
| R-407C | R-32 / R-125 / R-134a | 1,774 | 1,624 | 1,908 | 4,457 | 555 | +17.5% |
| R-410A | R-32 / R-125, 50/50 by mass | 2,088 | 1,923 | 2,256 | 4,715 | 665 | +17.3% |
| R-507A | R-125 / R-143a, 50/50 by mass | 3,985 | 3,985 | 4,775 | 7,290 | 1,525 | +19.8% |
Across all five blends above the AR5 → AR6 step is between +17.3% and +19.9% — it is systematic, not noise. So a refrigerant line computed on AR6 values against a framework that mandates AR5 is overstated by about a fifth, and the reverse understates it by the same. On a 12 kg R-410A charge with a 10% annual leak rate that is the difference between 2.31 and 2.71 tonnes CO₂e from one line item, before anyone has questioned your leak rate.
Which basis you owe. UNFCCC decision 18/CMA.1 mandates AR5 GWP-100 for national inventory reporting, and several corporate frameworks follow it; others have moved to AR6, and older baselines are often still on AR4. The rule is not “use the newest” — it is use the one your framework names, state which you used, and keep the gases separate so you can restate. Our GWP set consistency checker exists because mixing bases inside a single inventory is the failure that survives review.
The six newer blends are AR6-only, and honestly so. R-448A, R-449A, R-450A, R-452A, R-454B and R-513A are held on the three AR6 horizons and not on AR4 or AR5. That is not an omission on our side: their constituents include HFOs that the earlier assessment reports did not evaluate, so an AR5 figure for them would have to be invented. If a framework demands AR5 for one of these, that is a question for your assurer, not a lookup.
A coincidence worth not misreading: R-507A is 3,985 on both AR4 and AR5. That is not a copied value — the constituent GWPs changed between the reports and the half-and-half arithmetic happens to land on the same figure (AR5: 0.5 × 3,170 + 0.5 × 4,800; AR4: 0.5 × 3,500 + 0.5 × 4,470). Our data gates flag identical values across sources, and this pair is allow-listed with that reason recorded.
Application — formula & worked examples
Fugitive emissions (kg CO₂e) = mass of refrigerant leaked (kg) × GWP-100
Mass leaked is established either by mass balance (the refrigerant added during servicing to restore charge, from purchase/top-up records — the preferred method) or by screening (installed charge × an assumed annual leak rate). At end of life, the difference between charge and recovered mass is the leak.
Operating leak. A 100 kg R-410A chiller with an 8% annual leak rate: 100 × 0.08 = 8 kg leaked × 2,256 = 18,048 kg CO₂e in the year.
Servicing top-up (mass balance). If service records show 25 kg of R-404A added across the year to maintain charge, the leak is 25 kg × 4,728 = 118,200 kg CO₂e — over 118 tonnes from one system.
Low-GWP swap. Replacing that R-404A system with R-448A-class HFO blends, or the same duty on R-744 (CO₂, GWP = 1) or R-717 (ammonia, GWP = 0), collapses the direct fugitive term to a rounding error — the entire case for natural and HFO refrigerants.
Use the AR6 GWP-100 values here for GHG Protocol and CSRD greenhouse-gas inventory reporting. The EU F-Gas Regulation uses its own Annex GWP values to calculate CO₂-equivalent quotas and placing-on-market limits — these can differ from AR6 (the Regulation's figures derive from earlier assessments). Do not use one where the other is required. Always disclose which basis you applied.
Framework requirements
Refrigerant leakage is Scope 1 fugitive emissions under corporate GHG accounting, and separately regulated as a fluorinated-gas control regime.
| Framework | Role | GWP basis |
|---|---|---|
| GHG Protocol Corporate Standard | Scope 1 fugitive emissions | Latest IPCC assessment — AR6 |
| IPCC AR6 | Primary GWP-100 source | These ARE the AR6 values |
| EU F-Gas Regulation 2024/573 | HFC phasedown, quotas, bans | Regulation Annex GWPs (for compliance) |
| Kigali Amendment | Global HFC phase-down schedule | Montreal Protocol GWPs |
Common reporting errors
- Mixing GWP assessments. AR4, AR5 and AR6 give different values for most HFCs (e.g. R-134a is 1,430 under AR4 and 1,300 under AR5, 1,530 under AR6). Pick one basis for the whole inventory and disclose it.
- Using the EU F-Gas quota GWP for inventory reporting (or vice-versa). The Regulation's Annex GWPs are for quota compliance; corporate inventories use the latest IPCC assessment. They are not interchangeable.
- Treating a blend as one of its components. R-410A is not R-32; R-404A is not R-125. Use the blend's mass-weighted GWP, not a constituent's.
- Omitting legacy CFCs and HCFCs. Banned production does not mean zero inventory — leaks from legacy R-22, R-11 and R-12 equipment are real and very high-GWP.
- Counting refrigerant energy as the fugitive emission. The electricity to run the equipment is Scope 2; the leaked refrigerant is Scope 1 fugitive. They are separate lines.
- Assuming “low-GWP” means zero. HFOs and CO₂ are low, not nil; and their upstream and energy impacts still count elsewhere in the inventory.
- Estimating leaks by assumed rate when top-up records exist. The mass-balance method (refrigerant added to restore charge) is more accurate than a default leak rate — use it when service records are available.
Methodology, boundaries & uncertainty
What this dataset is. GWP-100 values for 51 refrigerants and fluorinated gases as implemented in the GreenCalculus MasterBrain. IPCC-characterised substances use AR6 (WGI, 2021); blends are the mass-weighted average of their AR6 component GWPs; substances not in an IPCC assessment use the EU F-Gas Regulation (EU) 2024/573 default. The Basis column on each table records which applies.
Boundary. Direct fugitive emissions of the refrigerant only (Scope 1). Excludes the Scope 2 energy of operating the equipment and any upstream manufacturing of the refrigerant.
Rounding policy. Values are reproduced at MasterBrain precision as published by the source. HFO values that round to near-zero at GWP-100 (e.g. R-1234yf = 0.501) are given, not rounded to zero, because they remain non-zero and some frameworks require them.
Uncertainty. IPCC AR6 GWP-100 values for well-studied HFCs are relatively precise; short-lived HFOs and the non-IPCC regulation defaults carry wider uncertainty. The dominant real-world uncertainty in a refrigerant inventory is almost always the leak quantity, not the GWP — invest measurement effort in mass balance, not in the factor.
Applicability. Global GWP-100 values. For 20-year GWP (some near-term policy analyses), use a GWP-20 source — not published here.
Implementation & provenance chain
- Primary sources — IPCC Sixth Assessment Report, WGI (2021), GWP-100 without climate-carbon feedbacks; and EU Regulation (EU) 2024/573 on fluorinated greenhouse gases, for substances not in AR6.
- MasterBrain — each refrigerant is curated under a stable
refrigerants.<name>key with its GWP basis, gas class and source reference; current version v2026.284 (2026-11-06). - REST & CSV — the
/refrigerant-gwp-factorsendpoint projects those rows as JSON; the CSV button below serves the identical set. - Calculators — the GreenCalculus refrigerant leakage calculator reads the same keys, so a published inventory and this page cannot diverge.
- Update plan — static reference; revalued on a new IPCC assessment or an amendment to the EU F-Gas Regulation. Any change is logged in the version history and bumps the dataset version.
Data access — REST API & CSV
The full 51-row dataset is available as a machine-readable REST endpoint and as a flat CSV download — the same rows shown above, versioned and citable.
Cache-Control: max-age=3600; X-GC-Version header signals dataset updates. /wp-json/greencalculus/v1/refrigerant-gwp-factors
Click to generate ↓
Citation guidance
Cite the primary sources. The GreenCalculus compilation reference is optional but appreciated.
IPCC (2021). Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the IPCC (Forster et al., Chapter 7 Supplementary Material, Table 7.SM.7). Cambridge University Press. — and European Union (2024). Regulation (EU) 2024/573 on fluorinated greenhouse gases. Official Journal of the European Union.
IPCC AR6 + EU F-Gas Regulation primary citations
Cite this dataset (GreenCalculus compilation). A versioned, machine-readable snapshot is archived on Zenodo with a citable DOI:
Say, Jeremiah (2026). Refrigerant & F-gas global warming potential (GWP) values (machine-readable) (v2026.59). GreenCalculus. Zenodo. https://doi.org/10.5281/zenodo.21455656
GreenCalculus dataset DOI
Frequently asked questions
GWP-100 (100-year global warming potential), which is the horizon required by corporate GHG reporting. For refrigerants characterised by the IPCC, GreenCalculus uses the latest assessment — AR6 (2021). For a small number of substances not yet in an IPCC assessment, the dataset uses the default value published in the EU F-Gas Regulation (EU) 2024/573. The Basis column on each table shows which applies to every refrigerant. AR4, AR5 and AR6 give materially different numbers for many HFCs, so always disclose the basis you used.
Refrigerant emissions are direct, Scope 1 fugitive emissions: multiply the mass of refrigerant leaked (in kg) by the GWP-100. The leaked mass is best established by mass balance — the refrigerant added during servicing to restore the system charge, from purchase and top-up records. Where records are unavailable, a screening estimate uses the installed charge times an assumed annual leak rate. At end of life, the leak is the charge minus the mass recovered. The GreenCalculus refrigerant leakage calculator applies these GWP values directly.
Not necessarily. The values here are for greenhouse-gas inventory reporting and use the latest IPCC assessment (AR6). The EU F-Gas Regulation uses its own Annex GWP values to calculate the CO₂-equivalent quotas, placing-on-market limits and equipment bans that govern regulatory compliance, and those Annex figures can differ from AR6 (they derive from earlier assessments). Use the AR6 values here for GHG Protocol and CSRD inventory reporting; use the Regulation's Annex for F-Gas quota compliance calculations.
A refrigerant blend's GWP-100 is the mass-weighted average of its component GWPs. For example R-410A (a 50/50 mass blend of R-32 and R-125) has a GWP-100 of about 2,256, between its components' 771 and 3,740. GreenCalculus computes each blend from the AR6 values of its constituents, so the blend and single-component values on this page are internally consistent. Never substitute a constituent's GWP for the blend's.
Because banned production does not mean zero inventory. CFCs (R-11, R-12) and HCFCs (R-22, R-123, R-141b) are phased out under the Montreal Protocol, but they remain in service in legacy equipment — older centrifugal chillers, automotive air-conditioning and foam — and leaks from that equipment are real, high-GWP Scope 1 emissions that must be inventoried until the equipment is retired and the refrigerant recovered.
Natural refrigerants have negligible or zero direct GWP: carbon dioxide (R-744) is 1 by definition, ammonia (R-717) and water (R-718) are effectively 0, and hydrocarbons such as propane (R-290, 0.02) and isobutane (R-600a, 0.006) are near-zero. They are the long-term endpoint of the F-gas phasedown. Their trade-offs are handling requirements — flammability for hydrocarbons, toxicity for ammonia, high operating pressure for CO₂ — not direct climate impact.
Scope 1. Leaked refrigerant is a direct fugitive emission from equipment your organisation owns or controls. It is entirely separate from the Scope 2 emissions of the electricity that runs the chiller, air-conditioner or heat pump. A common error is to count only the energy (Scope 2) and miss the fugitive refrigerant (Scope 1), which for a high-GWP charge can be the larger of the two.
R-1234yf is a hydrofluoro-olefin (HFO) — an unsaturated fluorocarbon with an atmospheric lifetime of only about ten days. Because GWP-100 integrates warming over a century, a molecule that is gone in days has almost no cumulative effect, giving a GWP-100 of 0.501. That is why HFOs like R-1234yf, R-1234ze(E) and R-1233zd(E), and the blends built from them, are replacing high-GWP HFCs in mobile air-conditioning, chillers and heat pumps.
R-134a (HFC-134a) has a GWP-100 of 1,530 under IPCC AR6. Older assessments give 1,430 (AR4) and 1,300 (AR5), so check which basis a report or regulation uses. One kilogram of leaked R-134a is about 1.5 tonnes of CO2e on the AR6 basis.
R-22 (HCFC-22) has a GWP-100 of 1,960 under IPCC AR6. It is an ozone-depleting HCFC, phased out under the Montreal Protocol (production has already ended in developed countries), but leaks from older equipment still count as Scope 1 emissions.
R-32 (HFC-32) has a GWP-100 of 771 under IPCC AR6, 677 under AR5 and 675 under AR4. US rules use the AIM Act’s exchange values, on which R-32 is 675, so it falls under the 700 limit for new residential air-conditioning there.
R-410A, a 50/50 blend of R-32 and R-125, has a GWP-100 of 2,256 under IPCC AR6, 1,923 under AR5 and 2,088 under AR4. On EPA’s values it is 2,088, three times the US limit of 700 for new residential air-conditioning, so new US systems use R-32 or R-454B instead; existing R-410A systems can still be serviced. In the EU it is being replaced by refrigerants below GWP 150 for small systems as the F-gas limits tighten.
R-454B, a blend of R-32 (68.9%) and R-1234yf (31.1%), has a GWP-100 of 531 under IPCC AR6. EPA’s Technology Transitions table, which applies the US 700 limit, lists it at 465, calculated from the older AR4 values. Either way it is below 700, so it can be used in new US air-conditioners and heat pumps.
Not for existing systems. Since 1 January 2025, new US residential and light-commercial AC and heat pump systems must use a refrigerant below GWP 700, which rules R-410A out of new equipment. Existing R-410A systems can still be serviced and recharged, and since 27 July 2026 systems built from components made before 2025 can still be installed. R-410A supply is being cut under the AIM Act phasedown.
The natural refrigerants have the lowest: ammonia (R-717) and water (R-718) have a GWP of 0, isobutane (R-600a) 0.006, propane (R-290) 0.02 and carbon dioxide (R-744) 1, on the IPCC AR6 basis. The lowest synthetic refrigerants are HFOs such as R-1234yf (0.501) and R-1234ze(E) (1.37). Safety and efficiency also decide the choice: hydrocarbons are flammable and ammonia is toxic.
Version history
| Version | Date | MasterBrain | Summary |
|---|---|---|---|
| 1.4 | 2026-10-13 | v2026.260 | Added “R-410A, R-32 and R-454B: the US switch”: the three refrigerants on EPA’s values (which set the US 700 limit) and on AR6, safety classes, what a leak of each is worth, the US dates from the AIM Act phasedown to EPA’s 26 May 2026 rule (effective 27 July 2026), and what it means for an existing R-410A system. Two FAQs added (R-454B; is R-410A banned) and the R-410A FAQ updated. |
| 1.3 | 2026-10-03 | v2026.212 | Added “Which refrigerant has the lowest GWP?”: a ranked table of the lowest-GWP refrigerants with safety classes and typical uses, and a table of EU and US GWP limits on new equipment. Five FAQs added (R-134a, R-22, R-32, R-410A, lowest GWP). All 51 values re-checked against the endpoint (no changes); R-1234yf label corrected. |
| 1.1 | 2026-07-26 | v2026.69 | GWP corrections. R-1234ze(E) corrected 7 → 1.37 — the 7 was the EPA SNAP / equipment-nameplate value mislabelled as AR6; the current IPCC AR6 GWP-100 is 1.37 (see the new R-1234ze to CO₂e converter). The R-134a constituent was also updated 1526 → 1530 (canonical AR6) across every blend containing it, re-rolling the mass-weighted GWPs: R-450A 645→643, R-515B 327→322, R-407A 2261→2262, R-407C 1906→1908, R-407F 1964→1965, R-417A 2506→2508, R-422A 3358→3359, R-422D 2915→2917, R-427A 2395→2397, R-437A 1927→1930, R-513A 672→673 (R-434A unchanged after rounding). |
| 1.0 | 2026-07-20 | v2026.59 | Initial publication. Complete refrigerant & F-gas GWP-100 dataset (51 substances): CFCs, HCFCs, single-component HFCs, HFC blends, HFOs and HFO blends, natural refrigerants, PFCs. IPCC AR6 basis plus EU F-Gas Regulation 2024/573 defaults. Formula, worked examples, framework mapping, 8-item FAQ, REST + CSV access. |
Put these GWP values to work
The GreenCalculus refrigerant leakage calculator applies these AR6 GWP-100 values directly — audit-grade outputs carry the GWP basis, gas class, source citation and MasterBrain version an assurance practitioner expects.