R-404A
R-404A is an HFC refrigerant blend with a GWP of 3,922 under the AIM Act exchange values[1]. It has been the default refrigerant in US commercial refrigeration since the R-22 phaseout: walk-in coolers and freezers, supermarket racks, condensing units, and ice machines.
Federal rules now restrict R-404A in new equipment, and supply shrinks under the AIM Act phasedown (40 CFR 84.7)[9]. Existing systems stay legal to run and service. The dates and sources are below.
R-404A quick facts
| Type | HFC blend: 44% R-125, 52% R-143a, 4% R-134a |
| ASHRAE safety class | A1 (no flame propagation) |
| GWP (AIM Act exchange values) | 3,922 |
| Temperature glide | Under 1 °F (near-azeotropic) |
| Lubricant | POE |
| Common use | Commercial refrigeration: walk-ins, racks, condensing units, ice machines |
Regulatory status
| Running and servicing existing equipment | Allowed[2] |
| Buying bulk cylinders | Section 608-certified buyers only[3] |
| New remote condensing units | Not allowed since Jul 27, 2026[2] |
| New cold storage systems | Not allowed since Jul 27, 2026[2] |
| New supermarket systems | Not allowed from Jan 1, 2027[2] |
| California bulk virgin sales | Banned since Jan 1, 2025 (verification of statute text in progress)[6] |
Rules
Federal
The 2023 Technology Transitions rule set GWP limits for new refrigeration systems by subsector[4]. EPA's May 2026 reconsideration kept interim limits in place and moved the strictest limits to January 1, 2032[2]. R-404A sits over every limit in the table, so each date marks the end of new R-404A installs in that subsector.
The rule restricts new systems. It does not ban running or servicing existing equipment[2].
| Subsector | Limit | Date | R-404A outcome |
|---|---|---|---|
| Remote condensing units (retail food) | GWP 1,400 interim | Jul 27, 2026[2] | GWP 150/300 on Jan 1, 2032 |
| Cold storage warehouses | GWP 700 interim | Jul 27, 2026[2] | GWP 150/300 on Jan 1, 2032 |
| Supermarket systems | GWP 1,400 interim | Jan 1, 2027[2] | GWP 150/300 on Jan 1, 2032 |
| Industrial process refrigeration (non-chiller) | GWP 150/300 | Jan 1, 2026[4] | unchanged by the 2026 rule |
Five consolidated petitions challenge the May 2026 rule in the D.C. Circuit, filed by industry and environmental groups (lead case HARDI v. EPA, No. 26-1168)[2]. The dates above are current law while the litigation runs. This page is reviewed against the Federal Register. The review date is shown below.
State
Several states restrict HFC equipment ahead of the federal schedule. Each row below is checked against the state's own regulation text:
| State | Rule | Effective |
|---|---|---|
| Washington | Supermarket systems and remote condensing units (new and retrofit): R-404A prohibited | Jan 1, 2020 |
| Washington | Cold storage warehouses (new): R-404A prohibited | Jan 1, 2023 |
| Vermont | Supermarket systems, remote condensing units, stand-alone units: listed-substance prohibitions include R-404A | Jan 1, 2021[8] |
California's SB 1206 bans bulk virgin refrigerant sales above GWP 2,200 from January 1, 2025, which covers R-404A. Certified reclaimed refrigerant is exempt[6]. The citation is CARB's program page, and the statute text is still being verified. Maryland, Rhode Island, and other states have their own HFC rules. Verify with your local authority having jurisdiction before an install decision.
Buying R-404A
Bulk R-404A can only be sold to Section 608-certified technicians and a short list of related buyers under 40 CFR 82.154[3]. That restriction has covered HFCs since January 1, 2018, and the 2020 leak-repair rescission did not touch it[3].
Replacements
For new equipment, R-448A and R-449A stay legal in supermarket and condensing-unit installs under the interim 1,400 GWP limit through the end of 2031 (91 FR 31284)[2]. The 2032 limits point to CO2, R-290, and A2L blends such as R-454C and R-455A. Match the path to the job: retrofit blends for existing R-404A systems, low-GWP designs for new installs.
R-404A PT chart
Saturation pressures for R-404A from -40 °F to 150 °F (-40 °C to 65.6 °C), computed from reference equations of state[7]. R-404A is near-azeotropic. Its temperature glide is under 1 °F, so the liquid and vapor columns sit close together.
| Temp (°F) | Liquid / bubble (psig) | Vapor / dew (psig) |
|---|---|---|
| -40 | 4.9 | 4.3 |
| -35 | 7.5 | 6.8 |
| -30 | 10.3 | 9.6 |
| -25 | 13.4 | 12.7 |
| -20 | 16.8 | 16.0 |
| -15 | 20.5 | 19.7 |
| -10 | 24.6 | 23.6 |
| -5 | 28.9 | 27.9 |
| 0 | 33.7 | 32.6 |
| 5 | 38.8 | 37.7 |
| 10 | 44.3 | 43.1 |
| 15 | 50.2 | 49.0 |
| 20 | 56.6 | 55.3 |
| 25 | 63.4 | 62.1 |
| 30 | 70.7 | 69.3 |
| 35 | 78.6 | 77.1 |
| 40 | 86.9 | 85.4 |
| 45 | 95.8 | 94.2 |
| 50 | 105.3 | 103.6 |
| 55 | 115.3 | 113.6 |
| 60 | 126.0 | 124.2 |
| 65 | 137.3 | 135.5 |
| 70 | 149.3 | 147.4 |
| 75 | 162.0 | 160.1 |
| 80 | 175.4 | 173.4 |
| 85 | 189.5 | 187.5 |
| 90 | 204.5 | 202.4 |
| 95 | 220.2 | 218.1 |
| 100 | 236.8 | 234.6 |
| 105 | 254.2 | 252.0 |
| 110 | 272.5 | 270.4 |
| 115 | 291.8 | 289.6 |
| 120 | 312.0 | 309.9 |
| 125 | 333.3 | 331.2 |
| 130 | 355.6 | 353.5 |
| 135 | 379.1 | 377.0 |
| 140 | 403.7 | 401.7 |
| 145 | 429.6 | 427.7 |
| 150 | 456.8 | 455.1 |
Use the vapor (dew) column to check superheat at the suction line. Use the liquid (bubble) column to check subcooling at the liquid line and for charging. R-404A glide is under 1 °F. Either column works for field checks. R-404A values are computed, not transcribed; see Sources.
Equipment rated for R-404A
Walk-in unit cooler models whose maker publishes R-404A ratings. Each page shows the full specifications with the page each value comes from.
1,091 models in the database carry R-404A ratings. A sample:
Questions
- Is R-404A banned?
No. Existing R-404A systems stay legal to run and service. Federal limits stop new R-404A installs by subsector: remote condensing units and cold storage from July 27, 2026, and supermarket systems from January 1, 2027 (91 FR 31284).
- Can I still buy R-404A?
Yes, with a Section 608 certification. Bulk cylinders are restricted to certified technicians and related buyers (40 CFR 82.154). California adds a bulk virgin sales ban above GWP 2,200 from 2025 (SB 1206).
- What replaces R-404A?
R-448A or R-449A for most retrofits and for new installs allowed under the interim limits through 2031. CO2, R-290, R-454C, or R-455A for new low-GWP designs. Check lubricant and TXV compatibility before any retrofit.
- Why is R-404A getting more expensive?
The AIM Act phasedown cuts HFC production and import allowances to 30% of baseline in 2029 (40 CFR 84.7). High-GWP blends like R-404A consume the most allowances per pound, so supply pressure lands on them first.
References
- ^1.40 CFR part 84, Appendix A: GWP exchange values (eCFR)
- ^2.91 FR 31284 (May 26, 2026): Technology Transitions reconsideration final rule
- ^3.40 CFR 82.154: refrigerant sales restriction (eCFR)
- ^4.88 FR 73098 (Oct 24, 2023): Technology Transitions final rule
- ^5.Chapter 173-443 WAC: Washington HFC regulation
- ^6.CARB HFC reduction program (SB 1206 overview) (accessed 2026-08-24)
- ^7.CoolProp 8.0 mixture models (Bell et al. 2014, doi:10.1021/ie4033999)
- ^8.10 V.S.A. § 586: Vermont HFC prohibitions
- ^9.40 CFR 84.7: HFC phasedown schedule (eCFR)
Updated