Substance profile
Cyclopropane
Cyclopropane is a colorless gas with resembles that of petroleum ether odor.
01 · Identification
What Cyclopropane is
Cyclopropane is a colorless gas with resembles that of petroleum ether odor. Its molecular formula is C3H6 and its molecular weight is 42.08 g/mol. It boils at -32.8 °C, melts at -127 °C, is soluble in water.
Under the GHS it carries the signal word Danger. It is classed as flammable agents - 4th degree.
02 · Identifiers
Cyclopropane identifiers and molecular data
Cyclopropane CAS number and EC number
Cyclopropane molecular formula and molecular weight
03 · GHS classification
Cyclopropane hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
Cyclopropane pictograms and signal word
Cyclopropane hazard class and category
| Hazard class | Category | From code | Pictogram |
|---|---|---|---|
| Flammable gases GHS chapter 2.2 | Category 1A | H220 | GHS02 |
Cyclopropane hazard statements (H-codes)
| Code | Hazard statement |
|---|---|
| H220 | Extremely flammable gas. |
This page lists only the codes assigned to Cyclopropane. The full reference lives on the hazard statements hub, the precautionary statements hub and the GHS pictograms hub.
Safety Data Sheet
Getting an SDS for Cyclopropane
A Safety Data Sheet is written for a product, not for a substance: the supplier of the grade you actually buy issues it, so two suppliers of Cyclopropane issue two different sheets. That is why there is no single authoritative SDS for a substance to download — what there is, is the job of collecting the sheets for the products you hold and keeping them current as suppliers revise them.
04 · Precautionary statements
Cyclopropane precautionary statements
CLP Annex VI assigns 3 precautionary statements to Cyclopropane. They are grouped the way a label groups them: what to do before handling, what to do when something has already happened, how to store it and how to dispose of it.
Prevention
What to do before and during handling so the hazard never happens.
Reading the notation. … is a blank the supplier fills in — not a truncated sentence.· [square brackets] mark a part printed only when it applies.
05 · Names in the regulation
Cyclopropane name in 23 EU languages
CLP Annex VI Part 3 is published in every language edition of the regulation, and the identification column is written out in each of them. Nothing below is translated by us: each line is the name as that edition prints it. Under Art. 18(2) the substance name from Annex VI is a lawful product identifier, so this is the wording to put on a label going to that market — and where the cell lists several designations, any one of them qualifies.
| Language | Name in CLP Annex VI Part 3 |
|---|---|
| Bulgarian български | циклопропан |
| Spanish español | Ciclopropano |
| Czech čeština | cyklopropan |
| Danish dansk | cyclopropan |
| German Deutsch | Cyclopropan |
| Estonian eesti | tsüklopropaan |
| Greek ελληνικά | κυκλοπροπάνιο |
| English English | cyclopropane |
| French français | cyclopropane |
| Croatian hrvatski | ciklopropan |
| Italian italiano | ciclopropano |
| Latvian latviešu | ciklopropāns |
| Lithuanian lietuvių | ciklopropanas |
| Hungarian magyar | ciklopropán |
| Maltese Malti | ċiklopropan |
| Dutch Nederlands | cyclopropaan |
| Polish polski | cyklopropan |
| Portuguese português | ciclopropano |
| Romanian română | ciclopropan |
| Slovak slovenčina | cyklopropán |
| Slovenian slovenščina | ciklopropan |
| Finnish suomi | syklopropaani |
| Swedish svenska | cyklopropan |
All 23 language editions of Annex VI carry this entry. Irish is the twenty-fourth official EU language and has no line here for a different reason: no consolidated CLP text has ever been published in Irish, so there is no Irish edition of Annex VI to quote a name from. Source: consolidated CLP, CELEX 02008R1272, language editions. © European Union, https://eur-lex.europa.eu — only the electronic Official Journal of the European Union is authentic.
06 · Label elements
Cyclopropane GHS label elements
Everything CLP Annex VI fixes for Cyclopropane, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Danger
Cyclopropane
- Extremely flammable gas.
- Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking.
- Keep container tightly closed.
- Store in a well-ventilated place.
Supplier name, address and telephone number· Product identifier·Nominal quantity
Need this as an actual label? Open Cyclopropane in the GHS label constructor →
07 · Health hazards
Cyclopropane health hazards and exposure limits
Cyclopropane hazard summary
Highly flammable; Mixtures with air or oxygen are flammable and explosive; Inhalation of high concentrations can cause CNS depression; [Hawley] Evaporating liquid can cause frostbite; In confined space spill, may displace air and act as simple asphyxiant; [CAMEO] Evaporating liquid can cause frostbite; [CHEMINFO]
Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
08 · Physical and chemical properties
Cyclopropane properties
Every value is shown with the conditions it was measured under and the source it came from. Where sources disagree, all values are listed rather than one being picked — the difference is usually a different form of the substance, not an error.
Cyclopropane boiling point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | -32.8 °C (-27 °F) | at 760 mmHg | HSDB |
| -32.89 °C (-27.2 °F) | at 760 mmHg | CAMEO | |
| -33.5 °C (-28.3 °F) | at 760 mmHg | DOE PAC |
Cyclopropane melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | -127.4 °C (-197.3 °F) | HSDB | |
| -127.39 °C (-197.3 °F) | CAMEO | ||
| -126.6 °C (-195.9 °F) | DOE PAC |
Cyclopropane density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 0.0019 g/cm³ | at 0 °C, at 760 mmHg | HSDB |
| 1.879 g/cm³ | at 0 °C | DOE PAC | |
| 0.676 g/cm³ | at -33 °C | CAMEO |
Cyclopropane solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | Soluble in benzene; very soluble in ethanol, ether. | HSDB | |
| FREELY SOL IN ALCOHOL, ETHER; SOL IN FIXED OILS, CONCN SULFURIC ACID; 1 VOL DISSOLVES IN ABOUT 2.7 VOL OF WATER AT 15 °C | at 15 °C | HSDB | |
| 3.81X10+2 mg/l water at 35 °C | at 35 °C | HSDB |
Cyclopropane vapor pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor pressure | 5410 mmHg | at 25 °C | HSDB |
Cyclopropane autoignition temperature
| Property | Value | Conditions | Source |
|---|---|---|---|
| Autoignition temperature | 497.78 °C (928 °F) | HSDB | |
| 500 °C (932 °F) | CAMEO |
Cyclopropane lower explosive limit (LEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Lower explosive limit (LEL) | 2.41 % by volume | HSDB | |
| 2.4 % by volume | CAMEO |
Cyclopropane upper explosive limit (UEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Upper explosive limit (UEL) | 10.3 % by volume | HSDB |
Cyclopropane vapor density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor density | 1.88 (air = 1) | HSDB |
Cyclopropane critical temperature and pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Critical temperature and pressure | 124.72 °C (256.5 °F) | HSDB | |
| 125.1 °C (257.2 °F) | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
09 · Fire and explosion
Cyclopropane fire and explosion behaviour
These are descriptions rather than measured values, so they are kept out of the table above and quoted here with the source that reported them.
Cyclopropane fire potential
VERY DANGEROUS FIRE HAZARD WHEN EXPOSED TO HEAT OR FLAME; CAN REACT WITH OXIDIZING MATERIALS.
Source: Hazardous Substances Data Bank (HSDB)
10 · Transport
Cyclopropane UN number and transport classification
Transport classification is a separate system from the GHS classification above. It decides how a package is marked and how a load may be carried; it does not follow from the workplace label, and the workplace label does not follow from it. The entries below are linked by CAS number, never by name.
Cyclopropane under UN 1027 — shipping name, class and packing group
Europe · ADR 2025, Table A
| Proper shipping name (3.1.2) | Class | Classification code | PG | Labels (column 5) |
|---|---|---|---|---|
| CYCLOPROPANE | 2 | 2F | — | |
Source: ADR 2025, Table A of Chapter 3.2 · ECE/TRANS/352 Vol. I (UNECE). Class 2 is “Gases” (ADR 2.1.1.1).
United States · 49 CFR 172.101 Hazardous Materials Table
| Proper shipping name (column 2) | Class or division | PG | Labels (column 6) |
|---|---|---|---|
| Cyclopropane | 2.1 | — | |
Source: 49 CFR 172.101 Hazardous Materials Table · eCFR, revision 2026-08-03. Class 2.1 is “Flammable gas” (49 CFR 173.2).
11 · Questions
Cyclopropane — frequently asked questions
What is the CAS number of Cyclopropane?
The CAS number of Cyclopropane is 75-19-4. Its EC number is 200-847-8.
What is the chemical formula of Cyclopropane?
The molecular formula of Cyclopropane is C3H6 and its molecular weight is 42.08 g/mol.
What does a Cyclopropane label have to show?
Under CLP Annex VI the label for Cyclopropane carries the pictograms Flame and Gas cylinder and the signal word is Danger.
Is Cyclopropane flammable?
Yes. CLP Annex VI assigns Cyclopropane H220 — extremely flammable gas.
Is Cyclopropane a carcinogen?
CLP Annex VI records no harmonised carcinogenicity classification for Cyclopropane. Annex VI is a list of agreed classifications, not a list of substances found safe, so this is an absence of a classification rather than a clean bill of health.
What is the boiling point of Cyclopropane?
The boiling point reported for Cyclopropane is -32.8 °C (-27 °F), at 760 mmHg (HSDB).
What is the melting point of Cyclopropane?
The melting point reported for Cyclopropane is -127.4 °C (-197.3 °F) (HSDB).
How should Cyclopropane be stored?
CLP Annex VI assigns Cyclopropane the storage statement P403.
Nearby
Substances next to Cyclopropane
Keep going: substances starting with C, or search the whole database by name, CAS number, pictogram or signal word.