RefrigerantASHRAE R-218

R218 PT Chart

Updated October 12, 2026

R-218

A1 Lower toxicity, no flame propagationPFC

Illustration of a refrigerant cylinder painted light green gray (RAL 7044), the color AHRI Guideline N-2017 calls for on all new refrigerant containers from 2020^{[1], section 4.8}. Label: R-218, safety class A1, GWP 8,830. No red band: AHRI Guideline N-2017 reserves it for flammable refrigerants^{[1], section 4.7}.

C3F8

Perfluorocarbon (PFC) — octafluoropropane (C₃F₈). All-fluorine, no hydrogen, no chlorine. ASHRAE A1. GWP 8,830, atmospheric lifetime 2600 years — one of the most persistent climate-active gases produced commercially. Niche use in specialty low-temperature cascade refrigeration and as fire-suppression agent FE-13.

R-218 saturation pressure is 54.6 PSIG at 40°F, 98.4 PSIG at 70°F, and 160.3 PSIG at 100°F. These are the gauge readings on a static, fully-saturated system; a running system's high side sits well above them. The full table below runs from −40°F to 150°F in 1°F steps.

Not yet checked against an independent source.

Saturation @ 70°F

98.4 PSIG

GWP (100-yr)

8,830 IPCC AR4

Boiling point

−34.2°F

R-218 PT calculator Superheat

R-218 PT chart — printable saturation table

Looking for the R-218 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).

R-218 PT Chart — Pressure-Temperature Saturation Table

Computed with CoolProp 7.2.0 in 1°F steps · hvacptcharts.com

R-218 · 1° increments · °F / PSIG

Tinted rows: NBP atmospheric crossover · 32°F H₂O freeze

R-218 pressure-temperature saturation table in Fahrenheit and PSIG
Temp (°F)	Pressure (PSIG)
−40°F	4.1 in. Hg vac.
−39°F	3.4 in. Hg vac.
−38°F	2.7 in. Hg vac.
−37°F	2.0 in. Hg vac.
−36°F	1.3 in. Hg vac.
−35°F	0.6 in. Hg vac.
−34°F NBP (atmospheric)	0.1
−33°F	0.5
−32°F	0.8
−31°F	1.2
−30°F	1.6
−29°F	2.0
−28°F	2.4
−27°F	2.9
−26°F	3.3
−25°F	3.7
−24°F	4.2
−23°F	4.6
−22°F	5.1
−21°F	5.6
−20°F	6.0
−19°F	6.5
−18°F	7.0
−17°F	7.5
−16°F	8.0
−15°F	8.6
−14°F	9.1
−13°F	9.6
−12°F	10.2
−11°F	10.7
−10°F	11.3
−9°F	11.9
−8°F	12.5
−7°F	13.1
−6°F	13.7
−5°F	14.3
−4°F	14.9
−3°F	15.6
−2°F	16.2
−1°F	16.9
0°F	17.6
1°F	18.2
2°F	18.9
3°F	19.6
4°F	20.4
5°F	21.1
6°F	21.8
7°F	22.6
8°F	23.3
9°F	24.1
10°F	24.9
11°F	25.7
12°F	26.5
13°F	27.3
14°F	28.2
15°F	29.0
16°F	29.9
17°F	30.7
18°F	31.6
19°F	32.5
20°F	33.4
21°F	34.4
22°F	35.3
23°F	36.2
24°F	37.2
25°F	38.2
26°F	39.2
27°F	40.2
28°F	41.2
29°F	42.2
30°F	43.3
31°F	44.3
32°F H₂O freeze	45.4
33°F	46.5
34°F	47.6
35°F	48.7
36°F	49.9
37°F	51.0
38°F	52.2
39°F	53.4
40°F	54.6
41°F	55.8
42°F	57.0
43°F	58.3
44°F	59.5
45°F	60.8
46°F	62.1
47°F	63.4
48°F	64.7
49°F	66.1
50°F	67.4
51°F	68.8
52°F	70.2
53°F	71.6
54°F	73.1
55°F	74.5
56°F	76.0
57°F	77.5
58°F	79.0
59°F	80.5
60°F	82.0
61°F	83.6
62°F	85.2
63°F	86.7
64°F	88.4
65°F	90.0
66°F	91.6
67°F	93.3
68°F	95.0
69°F	96.7
70°F	98.4
71°F	100.2
72°F	102.0
73°F	103.8
74°F	105.6
75°F	107.4
76°F	109.2
77°F	111.1
78°F	113.0
79°F	114.9
80°F	116.9
81°F	118.8
82°F	120.8
83°F	122.8
84°F	124.8
85°F	126.9
86°F	128.9
87°F	131.0
88°F	133.1
89°F	135.3
90°F	137.4
91°F	139.6
92°F	141.8
93°F	144.1
94°F	146.3
95°F	148.6
96°F	150.9
97°F	153.2
98°F	155.6
99°F	157.9
100°F	160.3
101°F	162.8
102°F	165.2
103°F	167.7
104°F	170.2
105°F	172.7
106°F	175.3
107°F	177.9
108°F	180.5
109°F	183.1
110°F	185.8
111°F	188.5
112°F	191.2
113°F	193.9
114°F	196.7
115°F	199.5
116°F	202.3
117°F	205.2
118°F	208.1
119°F	211.0
120°F	214.0
121°F	217.0
122°F	220.0
123°F	223.0
124°F	226.1
125°F	229.2
126°F	232.3
127°F	235.5
128°F	238.7
129°F	241.9
130°F	245.2
131°F	248.5
132°F	251.9
133°F	255.2
134°F	258.6
135°F	262.1
136°F	265.6
137°F	269.1
138°F	272.6
139°F	276.2
140°F	279.9
141°F	283.5
142°F	287.2
143°F	291.0
144°F	294.8
145°F	298.6
146°F	302.5
147°F	306.4
148°F	310.4
149°F	314.4
150°F	318.4

R-218 pressure-temperature saturation table in Celsius and kPa
Temp (°C)	Pressure (kPa)
−40°C	−14
−39°C	−10
−38°C	−5
−37°C NBP (atmospheric)	−1
−36°C	4
−35°C	8
−34°C	13
−33°C	19
−32°C	24
−31°C	29
−30°C	35
−29°C	41
−28°C	47
−27°C	53
−26°C	60
−25°C	66
−24°C	73
−23°C	80
−22°C	88
−21°C	95
−20°C	103
−19°C	111
−18°C	119
−17°C	128
−16°C	136
−15°C	145
−14°C	155
−13°C	164
−12°C	174
−11°C	184
−10°C	194
−9°C	205
−8°C	216
−7°C	227
−6°C	238
−5°C	250
−4°C	262
−3°C	274
−2°C	287
−1°C	300
0°C H₂O freeze	313
1°C	327
2°C	341
3°C	355
4°C	370
5°C	385
6°C	400
7°C	416
8°C	432
9°C	448
10°C	465
11°C	482
12°C	500
13°C	518
14°C	536
15°C	555
16°C	574
17°C	594
18°C	614
19°C	634
20°C	655
21°C	676
22°C	698
23°C	720
24°C	743
25°C	766
26°C	790
27°C	814
28°C	838
29°C	863
30°C	889
31°C	915
32°C	942
33°C	969
34°C	996
35°C	1,024
36°C	1,053
37°C	1,082
38°C	1,112
39°C	1,143
40°C	1,173
41°C	1,205
42°C	1,237
43°C	1,270
44°C	1,303
45°C	1,337
46°C	1,372
47°C	1,407
48°C	1,443
49°C	1,479
50°C	1,517
51°C	1,555
52°C	1,593
53°C	1,633
54°C	1,673
55°C	1,713
56°C	1,755
57°C	1,797
58°C	1,841
59°C	1,885
60°C	1,930
61°C	1,975
62°C	2,022
63°C	2,070
64°C	2,118
65°C	2,168
66°C	2,218

CoolProp 7.2.0 · PSIG/kPa = gauge · PSIA = PSIG + 14.6959 · kPa(abs) = kPa(gauge) + 101.325

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-218 PT chart data: CoolProp 7.2.0 (published Helmholtz equations of state / mixture models — see the source citations above).

Lower toxicity, no flame propagation

Lower toxicity (Occupational Exposure Limit ≥ 400 ppm). No flame propagation in air at standard atmospheric pressure and 60°C. R-134a, R-22, R-410A, R-404A, R-744 (CO2) are A1.

Flammability: None (no flame propagation)
Toxicity: Lower (OEL ≥ 400 ppm)

Classification per ANSI/ASHRAE Standard 34-2022. See full reference.

Saturation pressure-temperature curve

Pressure

Temperature

Highlight at°F

Quick lookup — R-218

Temp:°F

98.4PSIG(679 kPa)

Range: −40 to 150°F Open full PT calculator →

Common service temperatures

32°F

45PSIG

Freezing

45°F

61PSIG

Heat-pump heat

70°F

98PSIG

Standard

75°F

107PSIG

Test ref

80°F

117PSIG

Warm

95°F

149PSIG

Summer peak

Saturation values from CoolProp 7.2.0^[2]. Operating pressure on a running system differs — see the operating-pressure references for in-use values.

At a glance

Chemistry

C3F8

Octafluoropropane

Lubricant compatibility

POEPAOMO

Perfluorocarbon (PFC). Extremely long atmospheric lifetime and high GWP. Used in specialty low-temperature applications and as a fire suppression agent (FE-13).

Common applications

Low-temperature cascade refrigeration (specialty)
Fire suppression (clean agent, legacy)
Electronics testing baths

Properties

Boiling point (1 atm)
−34.2°F (−36.8°C)
Critical point
161.4°F (71.9°C) at 368 PSIG
Molar mass
188.02 g/mol
ODP
0
GWP (100-yr)
8,830 IPCC AR4 IPCC: AR4 8,830 · AR5 8,900 · AR6 9,290
Atmospheric lifetime
2600 years
New-equipment status (US)
Not an AIM Act regulated substance; 40 CFR 84.54 GWP limits don't apply.

What is R-218?

R-218 is octafluoropropane (C₃F₈) — a perfluorocarbon (PFC) where every hydrogen of propane has been replaced with fluorine. PFCs have no chlorine (zero ODP) and no hydrogen for atmospheric OH-radical attack (extremely long atmospheric lifetimes). R-218's atmospheric lifetime is 2,600 years; its GWP is 8,830. These are among the worst environmental profiles for any commercially-used refrigerant.

Commercial use of R-218 is restricted to specialty applications where its specific properties (low boiling point −34°F, A1 non-flammability, chemical inertness) are essential and where the climate impact is manageable through tight containment. Applications include specialty cascade low-temperature refrigeration (mid-stage in some autocascade designs), electronics testing baths (chemical inertness allows direct immersion of powered electronics), and as fire-suppression agent FE-13 in some applications (though FM-200 / HFC-227ea has largely displaced FE-13).

Where R-218 is used

Specialty low-temperature cascade refrigeration (mid-stage in some autocascade designs)
Electronics testing baths (immersion cooling of powered components)
Fire suppression (FE-13, legacy total-flooding systems)
Some semiconductor manufacturing applications
Not used in conventional HVAC

Regulatory & phase-down status

R-218 is not currently subject to a focused HVAC-segment phase-down. PFCs are fluorinated greenhouse gases under the F-gas Regulation; the EU quota phase-down applies to HFCs.

For applications where R-218 is currently used, the trend is toward containment improvements (closed-loop systems, reclamation programs) rather than substitution — partly because few alternatives match the specific properties of R-218 in its niche applications, and partly because the modest production volumes make targeted regulation less of a priority than larger-volume HFCs.

Service notes

POE and PAO oils are compatible. Mineral oil is not. R-218 is chemically inert, making it suitable for applications requiring direct contact with sensitive materials (electronics testing). Recovery is strictly required given the extreme atmospheric lifetime — any release contributes to atmospheric burden essentially permanently on human timescales.

EPA Section 608 covers refrigerant uses of R-218. PFC reporting requirements apply to many industrial uses regardless of HVAC classification.

Operating cycle

Phase-down timeline

R-218 is not an AIM Act regulated substance (not one of the 18 HFCs in 42 U.S.C. 7675(c), and not a blend containing one). The 40 CFR 84.54 GWP limits don't apply.

Global warming potential, in context

Frequently asked

›Why is R-218's atmospheric lifetime so long?

No hydrogen atoms. R-218 has only C-F bonds (and C-C bonds in the molecular backbone), which are essentially inert to OH attack. The only atmospheric removal mechanisms for PFCs are stratospheric photolysis by UV (very slow due to limited UV intensity at PFC absorption wavelengths) and very slow reaction with very-high-energy radicals. The result: PFCs persist for thousands of years.

›If R-218 is so environmentally damaging, why is it still used?

Niche applications where its specific properties are essential and containment is tight. Cascade refrigeration applications use it because its NBP (−34°F) fits a specific role between R-410A-class refrigerants and the ultra-low R-23 or R-744 cascade refrigerants.

›What is the GWP of R-218?

8,830. For comparison: R-410A is GWP 2,088; R-134a is 1,430; R-1234yf is 1. R-218 has roughly 4× the GWP of R-410A.

›Is R-218 affected by the AIM Act?

R-218 is not on the AIM Act's targeted HFC list (the AIM Act focuses on HFCs by ASHRAE designation). PFCs are addressed through different regulatory frameworks: Kyoto Protocol reporting, EU F-Gas Regulation, EPA reporting requirements for high-GWP industrial gases. The practical effect is similar — pressure to reduce emissions through containment and substitution where possible.

Download this dataset

Full PT chart for R-218 · CC BY 4.0 · attribute the source

CSV JSON

Sources & citations

[1]
2017 Guideline for Assignment of Refrigerant Container Colors (AHRI Guideline N-2017). AHRI. 2017. https://www.ahrinet.org/system/files/2023-06/AHRI_Guideline_N_2017.pdf (accessed October 2, 2026)
[2]
CoolProp 7.2.0. CoolProp (I. H. Bell, J. Wronski, S. Quoilin, V. Lemort). https://coolprop.org/ (accessed October 2, 2026). Bell, I. H.; Wronski, J.; Quoilin, S.; Lemort, V. Pure and Pseudo-pure Fluid Thermophysical Property Evaluation and the Open-Source Thermophysical Property Library CoolProp. Ind. Eng. Chem. Res. 53, 2498–2508 (2014). https://doi.org/10.1021/ie4033999