R454C Refrigerant21.5/78.5 R32/R1234yf · Opteon XL20 · Sub-150 commercial refrigeration
R454C is a zeotropic A2L blend containing 21.5% R32 and 78.5% R1234yf by mass. Its EPA GWP of 146 places it below the important 150 threshold used in many new-equipment regulations. R454C is aimed at new low- and medium-temperature commercial and industrial refrigeration, cold storage, remote condensing, supermarket and related equipment designed specifically for A2L refrigerants.
What is R454C refrigerant?
R454C is a two-component HFO/HFC refrigerant with very low GWP compared with R404A, R448A and R449A. It is not an A1 retrofit blend: its A2L classification and substantial temperature glide require equipment designed around charge limits, ignition-source control, ventilation/mitigation and bubble/dew-aware controls.
R454C refrigerant properties
Use these values for research and screening. For equipment design, charging and compliance, use the exact supplier PT data, SDS, OEM documentation and regulation that governs the project.
| Property | Reference | Engineering / source note |
|---|---|---|
| Designation | R454C | ASHRAE designation / Chemours Opteon XL20 |
| Nominal composition | R32/R1234yf = 21.5/78.5 mass % | NIST REFPROP / published property data |
| Refrigerant type | Zeotropic HFO/HFC blend | Two components |
| ODP | 0 | No ozone depletion |
| 100-year GWP | 146 | EPA Technology Transitions calculated value |
| Safety classification | A2L | Lower toxicity / lower flammability |
| Bubble point at ~1 atm | ≈ −46°C | Published blend property data |
| Dew point at ~1 atm | ≈ −37.8°C | Published blend property data |
| Glide at ~1 atm | ≈ 8.2 K endpoint difference | Operating/effective glide varies with condition |
| Critical temperature | ≈ 82.4°C | Published property data |
EPA Technology Transitions uses the values shown on this page. Older product literature may use IPCC AR4/AR5 or another assessment, so a different number is not automatically an error.
Where is R454C used?
Applications must be evaluated by system type, charge, compressor, heat exchanger, safety class and current regulation. The examples below describe recognized use contexts, not automatic approval for every installation.
Remote condensing units
New commercial refrigeration systems designed/listed for A2L operation.
Cold-storage warehouses
R454C fits the <150 GWP direction and is SNAP-acceptable subject to use conditions for new equipment.
Supermarket systems
EPA SNAP Rule 26 lists R454C for new supermarket systems subject to use conditions.
Stand-alone retail refrigeration
Rule 26 allows R454C in new stand-alone equipment subject to use conditions.
Industrial process refrigeration
R454C is accepted for new IPR systems under Rule 26 use conditions.
Commercial ice machines & ice rinks
EPA Rule 26 includes R454C in these new-equipment categories subject to specified conditions.
Continue through the Refrigerant Replacements and Low-GWP Refrigerants hubs for broader selection context.
Why R454C is fundamentally different from R448A/R449A retrofit blends
R448A and R449A deliberately preserve an A1 safety class for easier transition from R404A equipment. R454C moves to A2L in exchange for much lower GWP.
That change affects charge limits, ignition-source requirements, equipment listing, labels, service tools and potentially refrigerant detection / mitigation.
R454C should therefore be viewed primarily as a new-equipment design refrigerant rather than a casual field replacement for an A1 legacy system.
R454C temperature glide is a major engineering feature
Published composition/property data show a bubble point around −46°C and dew point around −37.8°C at approximately atmospheric pressure—a large endpoint separation.
Heat exchangers and controls need to account for the glide. In counterflow heat exchangers, glide can sometimes be used beneficially to improve temperature matching; in other designs it can complicate approach temperatures and control logic.
For service, superheat/subcooling calculations must use the correct bubble/dew reference and the PT data specified for R454C.
Why GWP 146 matters in 2026–2032 regulation
EPA’s current Technology Transitions reference puts R454C at 146, below the 150 line that appears repeatedly in U.S. refrigeration product/system restrictions.
SNAP Rule 26 also expanded A2L listings for R454C across retail food refrigeration, cold storage, industrial process refrigeration, commercial ice machines and ice rinks, subject to use conditions.
Being below 150 does not remove other requirements. Charge limits, UL/ASHRAE safety standards, equipment listing and local codes still determine whether a specific installation is legal.
A2L leak detection and mitigation are equipment-specific
Not every R454C installation uses the same detector or alarm threshold. Requirements depend on refrigerant charge, occupied volume, equipment construction, product standard and mitigation strategy.
Where a refrigerant detection system is part of the equipment safety design, the sensor must be validated for R454C response, operating range, humidity/temperature environment and required lifetime.
A portable service leak detector is not equivalent to a fixed mitigation sensor.
R454C vs R455A
The table highlights engineering differences rather than implying direct interchangeability.
| Characteristic | R454C | R455A |
|---|---|---|
| Composition | R32/R1234yf = 21.5/78.5 | R32/R1234yf/CO₂ = 21.5/75.5/3 |
| EPA GWP | 146 | 146 |
| Safety class | A2L | A2L |
| Temperature glide | High | Very high |
| CO₂ component | No | 3% |
| Primary role | New sub-150 commercial refrigeration | New sub-150 commercial/low-temp refrigeration |
| SNAP Rule 26 | Broad new-equipment listings with use conditions | Broad new-equipment listings with use conditions |
R454C safety: sub-150 GWP comes with A2L equipment requirements
R454C is A2L. The lower-flammability classification is not equivalent to A1. Equipment design must manage credible leak concentration, ignition sources, charge, airflow and servicing. A2L systems can also require detection and mitigation depending on the product standard and installation.
Ignition-source control
Electrical and hot-surface design must follow the applicable A2L equipment standard.
Charge & occupied volume
Permitted refrigerant quantity can depend on room size and mitigation design.
Service practice
Use A2L-rated recovery, vacuum, charging and leak-detection procedures.
Actual risk depends on charge, release rate, pressure, room volume, ventilation, ignition sources, equipment construction, alarm logic and service condition.
See the Refrigerant Safety Guide for classification context.
R454C refrigerant leak detection
Validate detector response to the finished blend
Use R454C-specific or explicitly validated A2L refrigerant sensing. NDIR and semiconductor technologies can be suitable depending on range and response requirements. The alarm objective—service leak localization, equipment mitigation or area protection—must be defined before selecting the sensor. GasNose does not currently list a dedicated R454C profile in its public directory, so the generic refrigerant-gas library is linked.
Portable service leak detectors, fixed area monitors, A2L mitigation sensors and refrigerant identifiers perform different functions. Define the alarm action and concentration range before selecting the technology.
Regulatory position of R454C in 2026
United States
EPA SNAP Rule 26 lists R454C as acceptable subject to use conditions in new commercial ice machines, industrial process refrigeration, cold storage warehouses, ice rinks, refrigerated food processing/dispensing, stand-alone units, supermarket systems and remote condensing units. EPA Technology Transitions GWP is 146, which is below the 150 thresholds used in many long-term refrigeration subsectors. The exact use conditions and equipment standards still apply.
European Union
R454C’s GWP below 150 aligns with many near-term EU F-gas thresholds better than R448A/R449A. However, Regulation (EU) 2024/573 also introduces later restrictions that can favor non-fluorinated refrigerants in specific equipment classes, so sub-150 is not equivalent to permanent exemption.
Is R454C being phased out?
R454C is positioned as a long-term lower-GWP option in applications where A2L is acceptable, but future-proofing still depends on application-specific F-gas rules, safety standards, charge and the potential move toward non-fluorinated technologies.
U.S. refrigeration limits differ by cold storage, supermarket, remote condensing, stand-alone product, industrial process and chiller category. A refrigerant may fit one pathway and fail another.
Use the Refrigerant Regulations Hub for regional research.
What should be compared with R454C?
Compare the real equipment pathway: retrofit vs new system, A1 vs A2L capability, GWP threshold, glide, compressor envelope, energy efficiency and service ecosystem.
Practical misconceptions about R454C
“GWP 146 means R454C can replace R404A in any existing system.”
Its A2L class means existing A1 equipment cannot be assumed compatible or approved.
“R454C and R454B are almost the same.”
They have very different R32/R1234yf ratios, GWP, glide and application focus.
“Below 150 means no refrigerant regulation applies.”
Safety standards, SNAP use conditions, charge limits and later non-fluorinated restrictions still matter.
“A2L detector requirements are universal.”
Detection and mitigation depend on equipment type, charge, room and product standard.
R454C refrigerant FAQ
Concise answers to common composition, retrofit, glide, safety and regulation questions.
What is R454C?
What is the EPA GWP of R454C?
Is R454C flammable?
Does R454C have temperature glide?
Can R454C replace R404A directly?
Where is R454C used?
Is R454C SNAP-approved in the U.S.?
Why is GWP 146 significant?
Does R454C require a leak sensor?
How should R454C be charged?
R454C sources and further reading
This profile uses current EPA regulatory references plus refrigerant supplier, NIST, scientific and GasNose resources. Re-check the latest edition before design or compliance decisions.
Working with R454C or planning a refrigerant transition?
Compare GWP, safety class, temperature glide, equipment compatibility and regulatory lifetime before selecting a refrigerant.
Technical Notice: This page is for refrigerant research and general technical reference. Refrigerant suitability, permitted charge, equipment approval, leak mitigation, servicing procedures and regulatory compliance depend on the exact equipment, installation and jurisdiction. Always verify current manufacturer documentation, SDS, applicable standards and local regulations before selecting, replacing, charging or servicing a refrigerant.