R-143a
Pure HFC (1,1,1-trifluoroethane, CH₃CF₃) — A2L mildly flammable, GWP 4470. Almost exclusively used as a blend component in R-404A (52%) and R-507A (50%); not used as standalone refrigerant due to flammability and very high GWP.
Lower toxicity. Flame propagates in air at 60°C, but with a low burning velocity (≤ 10 cm/s) and a heat of combustion < 19,000 kJ/kg. Requires A2L-rated equipment, leak detection, and charge limits per UL 60335-2-40 and ASHRAE 15. R-32, R-454B, R-1234yf, R-1234ze(E), R-452B, R-454C, R-455A, R-516A are A2L.
- Flammability
- Low (burning velocity ≤ 10 cm/s)
- Toxicity
- Lower (OEL ≥ 400 ppm)
Classification per ANSI/ASHRAE Standard 34-2022. See full reference.
Saturation pressure-temperature curve
Saturation values from CoolProp 7.2.0 R143a. Operating pressure on a running system differs — see the operating-pressure references for in-use values.
R-143a PT chart PDF — printable saturation table
Looking for the R-143a PT chart PDF for shop reference? The complete pressure-temperature saturation table is below — every 1° increment from −40°F to 150°F (or to the refrigerant's critical temperature). Use the Print / Save as PDF button in the table header to download a clean, table-only PDF (the rest of the page is hidden from the print output). Important service temperatures (normal boiling point, freezing point of water, residential AC evap and condenser targets) are tinted and tagged in the table for at-a-glance shop reference.
R-143a PT Chart — Pressure-Temperature Saturation Table
1° increments · Source: CoolProp 7.2.0 / manufacturer datasheet · hvacptcharts.com
| Temp (°F) | Pressure (PSIG) |
|---|---|
| -40°F | 5.8 |
| -39°F | 6.3 |
| -38°F | 6.8 |
| -37°F | 7.3 |
| -36°F | 7.8 |
| -35°F | 8.4 |
| -34°F | 8.9 |
| -33°F | 9.5 |
| -32°F | 10.1 |
| -31°F | 10.7 |
| -30°F | 11.3 |
| -29°F | 11.9 |
| -28°F | 12.5 |
| -27°F | 13.1 |
| -26°F | 13.8 |
| -25°F | 14.4 |
| -24°F | 15.1 |
| -23°F | 15.8 |
| -22°F | 16.5 |
| -21°F | 17.2 |
| -20°F | 17.9 |
| -19°F | 18.6 |
| -18°F | 19.4 |
| -17°F | 20.1 |
| -16°F | 20.9 |
| -15°F | 21.6 |
| -14°F | 22.4 |
| -13°F | 23.2 |
| -12°F | 24.0 |
| -11°F | 24.9 |
| -10°F | 25.7 |
| -9°F | 26.6 |
| -8°F | 27.4 |
| -7°F | 28.3 |
| -6°F | 29.2 |
| -5°F | 30.1 |
| -4°F | 31.0 |
| -3°F | 32.0 |
| -2°F | 32.9 |
| -1°F | 33.9 |
| 0°F | 34.9 |
| 1°F | 35.9 |
| 2°F | 36.9 |
| 3°F | 37.9 |
| 4°F | 39.0 |
| 5°F | 40.0 |
| 6°F | 41.1 |
| 7°F | 42.2 |
| 8°F | 43.3 |
| 9°F | 44.4 |
| 10°F | 45.6 |
| 11°F | 46.7 |
| 12°F | 47.9 |
| 13°F | 49.1 |
| 14°F | 50.3 |
| 15°F | 51.5 |
| 16°F | 52.8 |
| 17°F | 54.0 |
| 18°F | 55.3 |
| 19°F | 56.6 |
| 20°F | 57.9 |
| 21°F | 59.3 |
| 22°F | 60.6 |
| 23°F | 62.0 |
| 24°F | 63.4 |
| 25°F | 64.8 |
| 26°F | 66.2 |
| 27°F | 67.7 |
| 28°F | 69.1 |
| 29°F | 70.6 |
| 30°F | 72.1 |
| 31°F | 73.6 |
| 32°FH₂O freeze | 75.2 |
| 33°F | 76.7 |
| 34°F | 78.3 |
| 35°F | 79.9 |
| 36°F | 81.6 |
| 37°F | 83.2 |
| 38°F | 84.9 |
| 39°F | 86.6 |
| 40°F | 88.3 |
| 41°F | 90.0 |
| 42°F | 91.8 |
| 43°F | 93.5 |
| 44°F | 95.3 |
| 45°F | 97.2 |
| 46°F | 99.0 |
| 47°F | 100.9 |
| 48°F | 102.8 |
| 49°F | 104.7 |
| 50°F | 106.6 |
| 51°F | 108.5 |
| 52°F | 110.5 |
| 53°F | 112.5 |
| 54°F | 114.6 |
| 55°F | 116.6 |
| 56°F | 118.7 |
| 57°F | 120.8 |
| 58°F | 122.9 |
| 59°F | 125.1 |
| 60°F | 127.3 |
| 61°F | 129.5 |
| 62°F | 131.7 |
| 63°F | 133.9 |
| 64°F | 136.2 |
| 65°F | 138.5 |
| 66°F | 140.8 |
| 67°F | 143.2 |
| 68°F | 145.6 |
| 69°F | 148.0 |
| 70°F | 150.4 |
| 71°F | 152.9 |
| 72°F | 155.4 |
| 73°F | 157.9 |
| 74°F | 160.5 |
| 75°F | 163.0 |
| 76°F | 165.7 |
| 77°F | 168.3 |
| 78°F | 170.9 |
| 79°F | 173.6 |
| 80°F | 176.3 |
| 81°F | 179.1 |
| 82°F | 181.9 |
| 83°F | 184.7 |
| 84°F | 187.5 |
| 85°F | 190.4 |
| 86°F | 193.3 |
| 87°F | 196.2 |
| 88°F | 199.2 |
| 89°F | 202.2 |
| 90°F | 205.2 |
| 91°F | 208.2 |
| 92°F | 211.3 |
| 93°F | 214.4 |
| 94°F | 217.6 |
| 95°F | 220.8 |
| 96°F | 224.0 |
| 97°F | 227.2 |
| 98°F | 230.5 |
| 99°F | 233.8 |
| 100°F | 237.2 |
| 101°F | 240.6 |
| 102°F | 244.0 |
| 103°F | 247.4 |
| 104°F | 250.9 |
| 105°F | 254.4 |
| 106°F | 258.0 |
| 107°F | 261.6 |
| 108°F | 265.2 |
| 109°F | 268.9 |
| 110°F | 272.6 |
| 111°F | 276.3 |
| 112°F | 280.1 |
| 113°F | 283.9 |
| 114°F | 287.8 |
| 115°F | 291.6 |
| 116°F | 295.6 |
| 117°F | 299.5 |
| 118°F | 303.6 |
| 119°F | 307.6 |
| 120°F | 311.7 |
| 121°F | 315.8 |
| 122°F | 320.0 |
| 123°F | 324.2 |
| 124°F | 328.4 |
| 125°F | 332.7 |
| 126°F | 337.0 |
| 127°F | 341.4 |
| 128°F | 345.8 |
| 129°F | 350.3 |
| 130°F | 354.8 |
| 131°F | 359.3 |
| 132°F | 363.9 |
| 133°F | 368.5 |
| 134°F | 373.2 |
| 135°F | 377.9 |
| 136°F | 382.7 |
| 137°F | 387.5 |
| 138°F | 392.3 |
| 139°F | 397.3 |
| 140°F | 402.2 |
| 141°F | 407.2 |
| 142°F | 412.3 |
| 143°F | 417.4 |
| 144°F | 422.5 |
| 145°F | 427.7 |
| 146°F | 433.0 |
| 147°F | 438.3 |
| 148°F | 443.7 |
| 149°F | 449.1 |
| 150°F | 454.6 |
| Temp (°C) | Pressure (kPa) |
|---|---|
| -40°C | 40 |
| -39°C | 46 |
| -38°C | 53 |
| -37°C | 59 |
| -36°C | 66 |
| -35°C | 74 |
| -34°C | 81 |
| -33°C | 89 |
| -32°C | 97 |
| -31°C | 105 |
| -30°C | 114 |
| -29°C | 122 |
| -28°C | 131 |
| -27°C | 141 |
| -26°C | 150 |
| -25°C | 160 |
| -24°C | 170 |
| -23°C | 181 |
| -22°C | 192 |
| -21°C | 203 |
| -20°C | 214 |
| -19°C | 226 |
| -18°C | 238 |
| -17°C | 250 |
| -16°C | 263 |
| -15°C | 276 |
| -14°C | 290 |
| -13°C | 303 |
| -12°C | 318 |
| -11°C | 332 |
| -10°C | 347 |
| -9°C | 362 |
| -8°C | 378 |
| -7°C | 394 |
| -6°C | 410 |
| -5°C | 427 |
| -4°C | 445 |
| -3°C | 463 |
| -2°C | 481 |
| -1°C | 499 |
| 0°CH₂O freeze | 518 |
| 1°C | 538 |
| 2°C | 558 |
| 3°C | 578 |
| 4°C | 599 |
| 5°C | 621 |
| 6°C | 642 |
| 7°C | 665 |
| 8°C | 688 |
| 9°C | 711 |
| 10°C | 735 |
| 11°C | 759 |
| 12°C | 784 |
| 13°C | 810 |
| 14°C | 836 |
| 15°C | 862 |
| 16°C | 890 |
| 17°C | 917 |
| 18°C | 946 |
| 19°C | 974 |
| 20°C | 1,004 |
| 21°C | 1,034 |
| 22°C | 1,065 |
| 23°C | 1,096 |
| 24°C | 1,128 |
| 25°C | 1,160 |
| 26°C | 1,193 |
| 27°C | 1,227 |
| 28°C | 1,262 |
| 29°C | 1,297 |
| 30°C | 1,333 |
| 31°C | 1,369 |
| 32°C | 1,406 |
| 33°C | 1,444 |
| 34°C | 1,483 |
| 35°C | 1,522 |
| 36°C | 1,562 |
| 37°C | 1,603 |
| 38°C | 1,645 |
| 39°C | 1,687 |
| 40°C | 1,730 |
| 41°C | 1,774 |
| 42°C | 1,819 |
| 43°C | 1,864 |
| 44°C | 1,910 |
| 45°C | 1,958 |
| 46°C | 2,006 |
| 47°C | 2,054 |
| 48°C | 2,104 |
| 49°C | 2,155 |
| 50°C | 2,206 |
| 51°C | 2,258 |
| 52°C | 2,312 |
| 53°C | 2,366 |
| 54°C | 2,421 |
| 55°C | 2,477 |
| 56°C | 2,534 |
| 57°C | 2,593 |
| 58°C | 2,652 |
| 59°C | 2,712 |
| 60°C | 2,773 |
| 61°C | 2,836 |
| 62°C | 2,899 |
| 63°C | 2,964 |
| 64°C | 3,029 |
| 65°C | 3,096 |
Full saturation values at 1° increments — toggle between °F / PSIG and °C / kPa. Use Print / Save as PDF for laminated shop reference, or download the CSV / JSON below for use in other tools. R-143a PT chart data: CoolProp 7.2.0 (REFPROP-compatible Helmholtz EOS) or manufacturer datasheet, validated against AHRI Standard 700-2019.
At a glance
Chemistry
Lubricant compatibility
Used almost exclusively as a blend component (R-404A, R-507A). A2L mild flammability; high GWP.
Common applications
- Blend component in R-404A, R-507A, R-427A
- Standalone use is rare
Properties
- Boiling point (1 atm)-47.2°C / -53.0°F
- Critical point162.9°F at 531 PSIG
- Molar mass84.04 g/mol
- Temperature glideNegligible (0.00°F)
- ODP0
- GWP (AR5, 100-yr)4470
- GWP (AR6, 100-yr)5810
- Atmospheric lifetime51 years
What is R-143a?
R-143a is 1,1,1-trifluoroethane (CH₃CF₃) — a pure HFC with A2L safety classification and the highest GWP (4470) among mainstream HFC blend components [ashrae34][ipccar5]. R-143a is essentially never used as a standalone refrigerant — its A2L flammability and very high GWP make alternatives preferable for nearly all direct refrigeration applications.
R-143a's commercial role is exclusively as a blend component. The major HFC blends using R-143a: R-404A (52% R-143a — largest mass fraction), R-507A (50%), R-428A, R-427A, R-434A. In these blends R-143a provides volumetric refrigeration capacity at low-temperature operating conditions; the flammability is suppressed by R-125 in A1 blends.
Where R-143a is used
- Component in R-404A (52% mass) — primary low-temperature commercial refrigeration blend
- Component in R-507A (50%) — alternative R-502 replacement
- Component in R-427A — R-22 retrofit blend
- Component in R-434A — alternative R-22 retrofit
- Standalone use is essentially non-existent in commercial HVAC
Regulatory & phase-down status
R-143a faces phase-down pressure indirectly through the phase-down of HFC blends containing R-143a. R-404A (52% R-143a) and R-507A (50%) are aggressively phased down under EPA AIM Act and EU F-Gas Regulation [aimact]. As these blends are restricted for new equipment, R-143a production volumes decrease.
Modern low-GWP blends (R-454C, R-455A, R-448A, R-449A) contain little or no R-143a. The structural trajectory is away from R-143a use in commercial HVAC blend formulations.
Service notes
R-143a is essentially never encountered as a standalone refrigerant in field service. Service technicians work with R-143a as a component in HFC blends (primarily R-404A and R-507A); the blend behavior dominates service considerations.
POE oil compatible. Standard HFC service procedures apply when encountered in blend form [ahri700].
Operating cycle
Phase-down timeline
No phase-down milestones documented for R-143a in this build. This may mean: (a) no regulatory phase-down currently published; (b) the refrigerant has local regulatory schedules not yet transcribed into the site dataset; or (c) it is a specialty refrigerant outside the main regulatory frameworks. For authoritative current status, consult the EPA AIM Act allocations (40 CFR Part 84), EU F-Gas Regulation 517/2014 + 2024/573, and the relevant national implementations of the Kigali Amendment.
Global warming potential, in context
No peer-comparison group is defined for R-143a. Its 100-year GWP per IPCC AR5 is 4470 — above the EPA AIM Act 700 GWP cap and well above the EU F-Gas 150 cap.
Peer-comparison groups are defined for refrigerants that compete in the same application sector (residential AC, commercial MT/LT, chillers, mobile AC). Specialty or research-grade refrigerants without a clear peer set don't appear in any group; their GWP is shown above in absolute terms instead.
Reading the R-143a PT chart
R-143a's PT chart is a single saturation curve. The pressure envelope is high — R-143a at 70°F is approximately 198 PSIG (CoolProp 7.2.0). The vapor pressure profile is similar to R-125 and contributes to R-404A's and R-507A's pressure characteristics.
R-143a is rarely encountered as a standalone refrigerant in field service, so its standalone PT chart is primarily a reference for understanding blend behavior.
HFC chemistry — three fluorines on one carbon, three hydrogens on the other
R-143a is 1,1,1-trifluoroethane: CH₃CF₃. The asymmetric structure (three fluorines on one carbon, three hydrogens on the other) is what gives R-143a its A2L flammability — the methyl group (CH₃) provides combustible chemistry that the fully-fluorinated R-125 (CHF₂CF₃) lacks.
The long atmospheric lifetime (~52 years) is the chemistry feature driving R-143a's very high GWP. The trifluoromethyl group (CF₃) is resistant to OH radical attack; the molecule persists in the atmosphere for decades.
GWP 4470 — the highest of mainstream HFC blend components
R-143a's GWP of 4470 places it among the very highest of HFC refrigerants — exceeded only by some specialty PFCs (R-218 at 8830) and a few other long-lived fluorinated compounds. The very high GWP is the structural reason R-404A and R-507A (the major R-143a-containing blends) have very high overall GWPs of 3922 and 3985.
In R-404A's GWP arithmetic (mass-weighted): 0.52 × 4470 + 0.44 × 3500 + 0.04 × 1430 = 2324 + 1540 + 57 = 3921. R-143a contributes 59% of R-404A's total GWP despite being only 52% of the mass — the highest per-unit-mass GWP contribution.
R-143a in the commercial refrigeration phase-down chain
R-143a's commercial role is concentrated in R-404A and R-507A — both being aggressively phased down for new equipment under EPA AIM Act and EU F-Gas Regulation. As these blends face restrictions, R-143a production volumes decrease accordingly.
The modern low-GWP commercial refrigeration alternatives (R-454C, R-455A, R-448A, R-449A) contain little or no R-143a:
- R-448A: 0% R-143a (uses R-32 + R-125 for the A1 capacity components)
- R-449A: 0% R-143a
- R-454C: 0% R-143a (binary R-32/R-1234yf)
- R-455A: 0% R-143a (ternary R-744/R-32/R-1234yf)
The trajectory is structural — R-143a is being designed out of new HFC blend formulations to reduce GWP. The transition from R-404A to R-448A / R-449A retrofits and to R-454C / R-455A new equipment progressively eliminates R-143a from the commercial refrigeration refrigerant inventory.
How to think about R-143a in 2026 and beyond
R-143a's market role is shrinking as R-404A and R-507A phase down. Service supply for existing R-404A and R-507A equipment will continue indefinitely (reclaimed and ongoing production allocations), but production volumes for new R-143a-containing blends are decreasing.
For service technicians, R-143a is essentially invisible — work is on R-404A or R-507A blends, never on standalone R-143a. The blend service procedures dominate.
For equipment specifiers, the trajectory away from R-143a is the key trend. New commercial refrigeration equipment specifies R-454C / R-455A (no R-143a, A2L low-GWP) or R-448A / R-449A (no R-143a, A1 with moderate GWP reduction). R-143a-heavy blends like R-404A are no longer specified for new equipment installations in 2026.
Frequently asked
›What is R-143a used for?
Exclusively as a blend component in HFC formulations. The dominant uses: R-404A (52% R-143a) for low-temperature commercial refrigeration, R-507A (50%) as alternative R-502 replacement [ashrae34]. R-143a provides capacity in these blends; flammability is suppressed by R-125 (also a major component).
›What's R-143a's GWP?
4470 per IPCC AR5 — the highest among mainstream HFC blend components [ipccar5]. The long atmospheric lifetime (~52 years) drives the very high GWP. R-143a is the primary contributor to R-404A's GWP of 3922 — without R-143a, R-404A would have much lower GWP.
›Is R-143a flammable?
Yes — ASHRAE class A2L (mildly flammable) [ashrae34]. The flammability is part of why R-143a is never used standalone — combining A2L classification with very high GWP gives R-143a the worst of both characteristics for standalone refrigerant use.
›Why is R-143a used in blends if its GWP is so high?
For capacity at low-temperature operating conditions. R-143a's vapor pressure profile is well-suited to low-temperature commercial refrigeration applications (walk-in freezers, frozen food cases). R-404A's design used 52% R-143a content specifically to match R-502's low-temperature capacity in the same equipment.
Modern low-GWP blends achieve low-temperature capacity through different chemistry (R-32 plus R-1234yf and similar) without R-143a's very high GWP.
›Can R-143a be used as a refrigerant by itself?
Technically yes, but practically never. The A2L flammability would require A2L-rated equipment; the very high GWP (4470) is among the worst regulatory positions of any HFC. No commercial application uses R-143a standalone.
›What lubricant does R-143a use?
POE oil typically when encountered in blend form [ahri700]. Standalone R-143a (rare/nonexistent in practice) would use POE.
›Is R-143a being phased out?
Indirectly through the phase-down of R-404A and R-507A. As these blends face EPA AIM Act and EU F-Gas restrictions, R-143a production volumes decrease. Modern low-GWP blends use little or no R-143a.
Sources & citations
- [1]ASHRAE Standard 34-2022
- [2]IPCC AR5 (2014) Working Group I, Chapter 8, Table 8.A.1
- [3]CoolProp 7.2.0
- [4]EPA AIM Act — 40 CFR Part 84 Subpart BFinal Rule Oct 2021https://www.epa.gov/climate-hfcs-reduction
- [5]AHRI Standard 700-2019
- [6]NIST Chemistry WebBook — 1,1,1-Trifluoroethane (CAS 420-46-2)