Substance profile
Ethylene
Ethylene is a colorless gas with a sweet odor.
01 · Identification
What Ethylene is
Ethylene is a colorless gas with a sweet odor. Its molecular formula is C2H4 and its molecular weight is 28.05 g/mol. It boils at -104 °C, melts at -169 °C.
Under the GHS it carries the signal word Danger. It is classed as flammable agents - 4th degree.
02 · Identifiers
Ethylene identifiers and molecular data
Ethylene CAS number and EC number
Ethylene molecular formula and molecular weight
03 · GHS classification
Ethylene hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
Ethylene pictograms and signal word
Ethylene hazard class and category
| Hazard class | Category | From code | Pictogram |
|---|---|---|---|
| Flammable gases GHS chapter 2.2 | Category 1A | H220 | GHS02 |
| Specific target organ toxicity - single exposure GHS chapter 3.8 | Category 3 narcotic | H336 | GHS07 |
Ethylene hazard statements (H-codes)
| Code | Hazard statement |
|---|---|
| H220 | Extremely flammable gas. |
| H336 | May cause drowsiness or dizziness. |
This page lists only the codes assigned to Ethylene. 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 Ethylene
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 Ethylene 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
Ethylene precautionary statements
CLP Annex VI assigns 3 precautionary statements to Ethylene. 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
Ethylene 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 | етилен |
| Spanish español | Etileno |
| Czech čeština | ethen ethylen |
| Danish dansk | ethylen |
| German Deutsch | Ethen Ethylen |
| Estonian eesti | etüleen |
| Greek ελληνικά | αιθυλένιο |
| English English | ethylene |
| French français | éthylène |
| Croatian hrvatski | etilen |
| Italian italiano | etilene |
| Latvian latviešu | etilēns |
| Lithuanian lietuvių | etilenas |
| Hungarian magyar | etilén |
| Maltese Malti | etilen |
| Dutch Nederlands | etheen |
| Polish polski | eten etylen |
| Portuguese português | etileno |
| Romanian română | etilenă |
| Slovak slovenčina | etén etylén |
| Slovenian slovenščina | etilen |
| Finnish suomi | etyleeni |
| Swedish svenska | eten |
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
Ethylene GHS label elements
Everything CLP Annex VI fixes for Ethylene, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Danger
Ethylene
- Extremely flammable gas.
- May cause drowsiness or dizziness.
- 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 Ethylene in the GHS label constructor →
07 · Health hazards
Ethylene health hazards and exposure limits
Ethylene hazard summary
Inhalation of high concentrations cause CNS depression and anesthesia; [Merck Index] Simple asphyxiant; Inhalation of high concentrations can cause CNS depression; [ICSC] Ethylene, compressed (UN1962) has warning of explosive polymerization; [ERG 2016]
Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
Ethylene carcinogenicity classification
Evaluation: There is inadequate evidence in humans for the carcinogenicity of ethylene. There is inadequate evidence in experimental animals for the carcinogenicity of ethylene. Overall evaluation: Ethylene is not classifiable as to its carcinogenicity to humans (Group 3).
Source: Hazardous Substances Data Bank (HSDB)
An IARC group and a CLP classification answer different questions. IARC judges whether the evidence for cancer in humans is strong enough; CLP Annex VI is the legally binding EU classification. A substance can carry one and not the other.
08 · Physical and chemical properties
Ethylene 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.
Ethylene boiling point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | -103.8 °C (-154.8 °F) | HSDB | |
| -102.4 °C (-152.3 °F) | at 700 mmHg | HSDB | |
| -103.72 °C (-154.7 °F) | at 760 mmHg | CAMEO |
Ethylene melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | -169.18 °C (-272.5 °F) | HSDB | |
| -169.11 °C (-272.4 °F) | CAMEO | ||
| -169.2 °C (-272.6 °F) | ICSC |
Ethylene density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 0.569 g/cm³ | at -103.8 °C | CAMEO |
| 0.568 g/cm³ | at -104 °C | DOE PAC |
Ethylene solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | Slightly soluble in water | HSDB | |
| Very soluble in ethanol, ether; soluble in acetone acid, benzene | HSDB | ||
| In water, 131 mg/L at 25 °C | at 25 °C | HSDB |
Ethylene vapor pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor pressure | 52100 mmHg | at 25 °C | HSDB |
| 51200 mmHg | at 25 °C | DOE PAC | |
| 60760 mmHg | at 15 °C | ICSC |
Ethylene flash point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Flash point | -100 °C (-148 °F) | HSDB | |
| -136.11 °C (-213 °F) | CAMEO |
Ethylene autoignition temperature
| Property | Value | Conditions | Source |
|---|---|---|---|
| Autoignition temperature | 450 °C (842 °F) | HSDB | |
| 440 °C (824 °F) | ICSC |
Ethylene lower explosive limit (LEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Lower explosive limit (LEL) | 2.7 % by volume | HSDB | |
| 2.75 % by volume | CAMEO |
Ethylene upper explosive limit (UEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Upper explosive limit (UEL) | 36 % by volume | HSDB | |
| 28.6 % by volume | CAMEO |
Ethylene vapor density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor density | 0.98 (air = 1) | HSDB |
Ethylene odor threshold
| Property | Value | Conditions | Source |
|---|---|---|---|
| Odor threshold | Detection in air by odor (purity not specified) 2.60x10+2 ppm. | HSDB | |
| Odor Index at 20 °C = 57,100 | at 20 °C | HSDB | |
| Odor Threshold Low: 17.0 [ppm] | Haz-Map |
Ethylene critical temperature and pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Critical temperature and pressure | 9.2 °C (48.6 °F) | HSDB |
Ethylene corrosivity
| Property | Value | Conditions | Source |
|---|---|---|---|
| Corrosivity | Ethylene is a noncorrosive gas. | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
09 · Fire and explosion
Ethylene 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.
Ethylene fire potential
A highly flammable gas ... .
Source: Hazardous Substances Data Bank (HSDB)
10 · Handling and storage
Ethylene storage and handling
Ethylene safe storage
Fireproof. Separated from strong oxidants.
Source: ILO-WHO International Chemical Safety Cards (ICSCs)
Ethylene storage conditions
Store in cool dry, well-ventilated location. Protect against static electricity and lightning. Isolate from oxidizing materials, halogens, and other combustibles.
Source: Hazardous Substances Data Bank (HSDB)
Ethylene incompatible materials
Incompatible materials: Strong oxidizing agents, carbon tetrachloride, chlorine, copper, vinyl compounds.
Source: Hazardous Substances Data Bank (HSDB)
Ethylene reactivity
Peroxidizable monomer may initiate exothermic polymerization of the bulk material [Bretherick 1979. p. 160]. Ethylene in the presence of aluminum chloride may undergo a violent reaction [J. Inst. Pet. 33:254. 1947]. Ozone and ethylene react explosively [Berichte 38:3837]. Ethylene can polymerize at low pressure if catalyzed by titanium halides. (Sundaram, K. M, M. M. Shreehan, E. F. Olszewski. "Ethylene." Kirk-Othmer Encyclopedia of Chemical Technology. John Wiley & Sons, Inc. 2001.)
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Ethylene in the storage compatibility matrix →
11 · Transport
Ethylene 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.
The same CAS number is shipped under more than one UN number. Which entry applies follows from the form and the concentration of the consignment — read the proper shipping name, not the CAS.
Ethylene under UN 1038 — shipping name, class and packing group
Europe · ADR 2025, Table A
| Proper shipping name (3.1.2) | Class | Classification code | PG | Labels (column 5) |
|---|---|---|---|---|
| ETHYLENE, REFRIGERATED LIQUID | 2 | 3F | — | |
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) |
|---|---|---|---|
| Ethylene, refrigerated liquid (cryogenic liquid) | 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).
Ethylene under UN 1962 — shipping name, class and packing group
Europe · ADR 2025, Table A
| Proper shipping name (3.1.2) | Class | Classification code | PG | Labels (column 5) |
|---|---|---|---|---|
| ETHYLENE | 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) |
|---|---|---|---|
| Ethylene | 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).
Ethylene under UN 3138 — shipping name, class and packing group
Europe · ADR 2025, Table A
| Proper shipping name (3.1.2) | Class | Classification code | PG | Labels (column 5) |
|---|---|---|---|---|
| ETHYLENE, ACETYLENE AND PROPYLENE MIXTURE, REFRIGERATED LIQUID containing at least 71.5 % ethylene with not more than 22.5 % acetylene and not more than 6 % propylene | 2 | 3F | — | |
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) |
|---|---|---|---|
| Ethylene, acetylene and propylene in mixture, refrigerated liquid with at least 71.5 percent ethylene with not more than 22.5 percent acetylene and not more than 6 percent propylene | 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).
12 · Questions
Ethylene — frequently asked questions
What is the CAS number of Ethylene?
The CAS number of Ethylene is 74-85-1. Its EC number is 200-815-3.
What is the chemical formula of Ethylene?
The molecular formula of Ethylene is C2H4 and its molecular weight is 28.05 g/mol.
What does a Ethylene label have to show?
Under CLP Annex VI the label for Ethylene carries the pictograms Flame, Gas cylinder and Exclamation mark and the signal word is Danger.
Is Ethylene flammable?
Yes. CLP Annex VI assigns Ethylene H220 — extremely flammable gas. The flash point reported for it is -100 °C (-148 °F) (HSDB).
Is Ethylene a carcinogen?
CLP Annex VI records no harmonised carcinogenicity classification for Ethylene. 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. IARC places it in Group 3: not classifiable as to its carcinogenicity to humans.
What is the boiling point of Ethylene?
The boiling point reported for Ethylene is -103.8 °C (-154.8 °F) (HSDB).
What is the melting point of Ethylene?
The melting point reported for Ethylene is -169.18 °C (-272.5 °F) (HSDB).
How should Ethylene be stored?
CLP Annex VI assigns Ethylene the storage statement P403. Store in cool dry, well-ventilated location. Protect against static electricity and lightning. Isolate from oxidizing materials, halogens, and other combustibles. (Hazardous Substances Data Bank (HSDB))
Nearby
Substances next to Ethylene
Keep going: substances starting with E, or search the whole database by name, CAS number, pictogram or signal word.