Identifiers for search
| Name | HFC-227ea (Heptafluoropropane) |
| Formula | C₃HF₇ |
| IUPAC name | 1,1,1,2,3,3,3-heptafluoropropane |
| CAS number | 431-89-0 |
| EC number | 207-079-2 |
| UN number | 3296 — Heptafluoropropane |
| Transport class (ADR/RID) | 2.2 (Non-flammable, non-toxic gases) |
| PubChem CID | 67940 |
| Synonyms | — |
Physical & chemical properties
| Molar mass | 170.03 g/mol |
| Boiling point (1 atm) | -17.3 °C |
| Melting point | -131 °C |
| Critical temperature | 100 °C |
| Critical pressure | 29.5 bar |
| Vapour pressure | 3.993 bar at 20 °C |
| Gas density | 7.9184 kg/m³ (0 °C, 1013 mbar) |
| Relative density (air = 1) | 6.1244 |
| Solubility in water | — |
| Appearance | gas liquefied under pressure, colourless, odourless, ethereal odour |
| Odour | odourless |
| 1 ppm at 20 °C | 7.07 mg/m³ |
Behaviour with temperature and pressure
Boiling point -17.3 °C at 1 atm: a liquefied gas under its own vapour pressure in cylinders. Critical point 100 °C / 29.5 bar: below this temperature it can be stored as a liquid; cylinder pressure then equals the vapour pressure. Vapour pressure ≈ 3.993 bar at 20 °C — this is the pressure inside a cylinder or a switchgear compartment at that temperature, and it rises steeply with temperature (Clausius–Clapeyron). Relative density 6.1244 (air = 1): heavier than air — accumulates in pits, cable basements and at floor level; place sensors low. Conversion at 20 °C, 1013 mbar: 1 ppm = 7.07 mg/m³; NDIR reads partial pressure, so readings scale with absolute pressure (value = reading × P/1013) and must be pressure-compensated.
// Non-combustible gas., Gas is heavier than air., Danger of suffocation at high concentrations due to oxygen displacement.
Hazards & safety
NFPA 704
health · flammability · instability · special
GHS / CLP pictograms
| Hazard class | asphyxiant; greenhouse gas (F-gas Annex I) |
| GHS signal word | Warning |
| CLP classification | Gases under pressure, liquefied gas; H280 |
| Hazard statements | H280: Contains gas under pressure; may explode if heated. |
| Lower / upper explosion limit | non-flammable |
| Auto-ignition temperature | 532 °C · T1 |
| Seveso III named substance | no |
Exposure limits
| EU indicative OELV (8 h TWA) | no EU IOELV |
| EU IOELV short-term (15 min) | — |
| Germany AGW (TRGS 900) | — |
| Netherlands | wettelijke grenswaarde per Arboregeling bijlage XIII — SER grenswaarden database |
| NIOSH REL (USA) | — |
| OSHA PEL (USA) | — |
| IDLH | — |
// Limits change: always confirm the current national value before setting an alarm. Values above were read from the EU directives / GESTIS / NIOSH pages listed in Sources.
Effect on people
Low toxicity (used as a fire-suppression agent at 7–9 vol%); cardiac sensitisation NOAEL ~9 %. Decomposes to HF in fire. Heavier than air (6×).
Recommended monitoring
- NDIR (8–9 µm) for fire-suppression agent room monitoring (concentration proof after discharge, leak detection of cylinders).
- Design concentration 7–9 vol%; NOAEL 9 % (cardiac sensitisation).
Climate & atmosphere
| GWP₁₀₀ — IPCC AR6 | 3600 |
| GWP₁₀₀ — IPCC AR4 | 3220 |
| GWP used in Reg. (EU) 2024/573 | 3220 |
| Atmospheric lifetime | 36 years |
| Ozone depletion potential | 0 |
| Main IR absorption band (NDIR) | 8.0–9.0 µm (C–F stretch, ≈1150–1250 cm⁻¹) |
Regulation windows
- F-gas 2024/573 Annex I (GWP 3220) — fire-protection equipment leak checks
- ISO 14520 / EN 15004 clean-agent systems
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Tremon Solutions (2026). HFC-227ea (C₃HF₇) — properties, exposure limits, NDIR monitoring. Tremon gas reference. https://www.tremon.nl/gases/r227ea (accessed 2026-09-17).
BibTeX · embed card · QR
@misc{tremon_r227ea_2026,
author = {Tremon Solutions},
title = {HFC-227ea (C3HF7) — properties, exposure limits, NDIR monitoring},
howpublished = {Tremon gas reference, \url{https://www.tremon.nl/gases/r227ea}},
year = {2026},
note = {accessed 2026-09-17}
}<a href="https://www.tremon.nl/gases/r227ea"><img src="https://www.tremon.nl/assets/og/r227ea.png" alt="HFC-227ea — Tremon gas reference" width="600"></a>
Text and tables on this page: CC BY 4.0 — copy them into your report, SOP or slide with the link above. Data were read from the primary sources listed below; check the current national limit before setting an alarm.
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Other gases
https://www.tremon.nl/gases/r227ea · Tremon Solutions, Eindhoven · [email protected] · printed from the Tremon gas reference, data as of 2026-09-17 · CC BY 4.0Sources
- https://gestis-database.dguv.de/data?name=490964
- https://pubchem.ncbi.nlm.nih.gov/compound/67940
- IPCC AR6 WG1 Ch.7 Supplementary Material, Table 7.SM.7 (https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_Chapter07_SM.pdf)
- IPCC AR4 WG1 Ch.2, Table 2.14 (https://www.ipcc.ch/site/assets/uploads/2018/02/ar4-wg1-chapter2-1.pdf)
- Regulation (EU) 2024/573, Annex I/III (https://eur-lex.europa.eu/eli/reg/2024/573/oj)
- HITRAN/NIST IR band positions (approximate centre of the strongest band used for NDIR; https://hitran.org, https://webbook.nist.gov)
// Data compiled 2026-09-17 from the listed primary sources; null values were left blank rather than estimated.