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Propene

Athanor · official

C3H6 · 42.08 g/mol

IUPAC name: prop-1-ene

Also called propylene, methylethylene

Open in Athanor
The structure of Propene
Drawn from its SMILES with RDKit411
FlammableCompressed gasDangerExtremely flammable gas

Names and identifiers

IUPAC name
prop-1-ene
Synonyms
propylene, methylethylene, PROPYLENE
+ 37 more

prop-1-ene, 1-Propene, Methylethylene, Methylethene, 1-Propylene, NCI-C50077, AUG1H506LY, R 1270, DTXSID5021205, CHEBI:16052, isopropylidene, RefChem:9088, DTXCID501205, 204-062-1, Propene-2-13C, MFCD00009279, Propene-1-13C (gas), CH3CH=CH2, CH2=CH-CH3, Propene (3,3,3-D3), PROPENE-2-D1, Propene (2.0-3.5% in Hexane), Propene (2.0-3.5% in Heptane), Propene, pure, CCRIS 1356, HSDB 175, EINECS 204-062-1, UN1077, UNII-AUG1H506LY, Polipropene 25, EINECS 292-050-7, Propylene, >=99%, endo-Ser39-Tirzepatide, PROPYLENE [MI], PROPYLENE [HSDB], PROPYLENE [IARC], SCHEMBL192

Molecular formula
C3H6
Empirical formula
CH2
Molecular weight
42.08 g/mol
Exact mass
42.04695
CAS number
115-07-1
PubChem CID
8252
Canonical SMILES
CC=C
Isomeric SMILES
CC=C
InChI
InChI=1S/C3H6/c1-3-2/h3H,1H2,2H3
InChIKey
QQONPFPTGQHPMA-UHFFFAOYSA-N
Molfile

Names, InChI and the identifiers from PubChem, retrieved 2026-10-14.

Physical properties

TemperaturePressureDensity
Appearance
Propylene is a colorless gas with a faint petroleum like odor. It is shipped as a liquefied gas under its own vapor pressure. For transportation it may be stenched. Contact with the liquid can cause frostbite. It is easily ignited. The vapors are heavier than air. Any leak can either be liquid or vapor. It can asphyxiate by the displacement of air. Under prolonged exposure to fire or intense heat the containers may rupture violently and rocket. It is used to make other chemicals. Can cause explosion.[1]
4 values

From CAMEO Chemicals, the most authoritative source here.

ValueAs writtenSource
–shownPropylene is a colorless gas with a faint petroleum like odor. It is shipped as a liquefied gas under its own vapor pressure. For transportation it may be stenched. Contact with the liquid can cause frostbite. It is easily ignited. The vapors are heavier than air. Any leak can either be liquid or vapor. It can asphyxiate by the displacement of air. Under prolonged exposure to fire or intense heat the containers may rupture violently and rocket. It is used to make other chemicals. Can cause explosion.[1] CAMEO Chemicals
–Liquid; Gas Vapor; Liquid; Gas Vapor[2] EPA Chemical Data Reporting (CDR)
–COLOURLESS COMPRESSED LIQUEFIED GAS.[3] ILO-WHO International Chemical Safety Cards (ICSCs)
–Colorless gas with a faint petroleum like odor.[4] Occupational Safety and Health Administration (OSHA)
Odor
Faint, petroleum-like[5]
2 values

From Hazardous Substances Data Bank (HSDB), the most authoritative source here.

ValueAs writtenSource
–Practically odorless; aromatic[5] Hazardous Substances Data Bank (HSDB)cites Carreon T, Herrick RL; Aliphatic Hydrocarbons. Patty's Toxicology. 6th ed. (1999-2017). New York, NY: John Wiley & Sons, Inc. On-line Posting Date: 17 Aug 2012
–shownFaint, petroleum-like[5] Hazardous Substances Data Bank (HSDB)cites NOAA; CAMEO Chemicals. Database of Hazardous Materials. Propylene (115-07-1). Natl Ocean Atmos Admin, Off Resp Rest; NOAA Ocean Serv. Available from, as of Jul 6, 2017: https://cameochemicals.noaa.gov/
Melting point
-185.2 °C (-301.4 °F, NTP 1992)[1]
4 values

4 of 4 sources agree on it (most common value).

ValueAs writtenSource
−185.2 °Cshown-301.4 °F (NTP, 1992)[1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
−185 °C-185 °C[3] ILO-WHO International Chemical Safety Cards (ICSCs)
−185.2 °C-301.4 °F[4] Occupational Safety and Health Administration (OSHA)
−185 °C-185 °C[6] PAC Chemical Database, U.S. Department of Energy
Boiling point
-47.7 °C @760 [mmHg][6]
4 values

4 of 4 sources agree on it (most common value).

ValueAs writtenSource
−47.7 °C-53.9 °F at 760 mmHg (NTP, 1992)[1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
−48 °C-48 °C[3] ILO-WHO International Chemical Safety Cards (ICSCs)
−47.7 °C-53.9 °F[4] Occupational Safety and Health Administration (OSHA)
−47.7 °Cshown-47.7 °C @760 [mm Hg][6] PAC Chemical Database, U.S. Department of Energy
Density
0.609 at -47.0 °C (-52.6 °F) (USCG, 1999) - Less dense than water[1]
4 values

2 of 4 sources agree on it (most common value).

ValueAs writtenSource
–shown0.609 at -52.6 °F (USCG, 1999) - Less dense than water[1] CAMEO Chemicalscites U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
–Relative density (water = 1): 0.5[3] ILO-WHO International Chemical Safety Cards (ICSCs)
–0.609 at -52.6 °F[4] Occupational Safety and Health Administration (OSHA)
–0.581 @ 0°C[6] PAC Chemical Database, U.S. Department of Energy
Solubility in water
Solubility in water: poor[3]
5 values

From ILO-WHO International Chemical Safety Cards (ICSCs), the most authoritative source here.

ValueAs writtenSource
–44.6 mL/100 mL (NTP, 1992)[1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
–In water, 200 mg/L at 25 °C[5] Hazardous Substances Data Bank (HSDB)cites McAuliffe C; J Phys Chem 70: 1267-75 (1966)
–In water, 44.6 mL gas/100 mL at 20 °C[5] Hazardous Substances Data Bank (HSDB)cites Calamur N, Carrera M; Propylene. Kirk-Othmer Encyclopedia of Chemical Technology. (1999-2017). New York, NY: John Wiley & Sons. Online Posting Date: 2 Dec 2005
–For more Solubility (Complete) data for Propylene (7 total), please visit the HSDB record page.[5] Hazardous Substances Data Bank (HSDB)
–shownSolubility in water: poor[3] ILO-WHO International Chemical Safety Cards (ICSCs)
log P
1.77[3]
2 values

2 of 2 sources agree on it (most common value).

ValueAs writtenSource
–log Kow = 1.77[5] Hazardous Substances Data Bank (HSDB)cites Hansch, C., Leo, A., D. Hoekman. Exploring QSAR - Hydrophobic, Electronic, and Steric Constants. Washington, DC: American Chemical Society., 1995., p. 6
–shown1.77[3] ILO-WHO International Chemical Safety Cards (ICSCs)
Vapor pressure
7600 [mmHg] @19.8 °C[6]
7 values

2 of 5 sources agree on it (most common value).

ValueAs writtenSource
1 mmHg1 mmHg at -205.4 °F[1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
760 mmHg760 mmHg at -53.9 °F (NTP, 1992)[1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
7600 mmHgVP: 10 atm at 19.8 °C[5] Hazardous Substances Data Bank (HSDB)cites Lewis, R.J. Sr. (ed) Sax's Dangerous Properties of Industrial Materials. 12th Edition. Wiley-Interscience, Wiley & Sons, Inc. Hoboken, NJ. 2012., p. V5: 3770
8690 mmHg8.69X10+3 mm Hg at 25 °C /Extrapolated/[5] Hazardous Substances Data Bank (HSDB)cites Daubert, T.E., R.P. Danner. Physical and Thermodynamic Properties of Pure Chemicals Data Compilation. Washington, D.C.: Taylor and Francis, 1989.
8700 mmHgVapor pressure, kPa at 25 °C: 1158[3] ILO-WHO International Chemical Safety Cards (ICSCs)
1 mmHg1 mmHg at -205.4 °F[4] Occupational Safety and Health Administration (OSHA)
7600 mmHgshown7600 [mm Hg] @19.8 °C[6] PAC Chemical Database, U.S. Department of Energy
Flash point
-108 °C (-162 °F)[5]
3 values

3 of 3 sources agree on it (most common value).

ValueAs writtenSource
−108 °C-162 °F (NTP, 1992)[1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
−108 °Cshown-162 °F (-108 °C)[5] Hazardous Substances Data Bank (HSDB)cites Lewis, R.J. Sr.; Hawley's Condensed Chemical Dictionary 14th Edition. John Wiley & Sons, Inc. New York, NY 2001., p. 930
−108 °C-162 °F[4] Occupational Safety and Health Administration (OSHA)
Autoignition temperature
455 °C (851 °F)[5]
3 values

2 of 3 sources agree on it (most common value).

ValueAs writtenSource
455 °C851 °F (USCG, 1999)[1] CAMEO Chemicalscites U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
455 °Cshown851 °F (455 °C)[5] Hazardous Substances Data Bank (HSDB)cites National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 325-101
460 °C460 °C[3] ILO-WHO International Chemical Safety Cards (ICSCs)

Each value as its source reports it, with the source's number after it (listed under References). Where several sources report a property, the row shows the value most of them agree on, the rule the app uses; open the values to see every one.

Calculated

Heavy atoms
3
Rings
0
Aromatic rings
0
Fraction sp³ carbons (Fsp3)
0.33
H-bond donors
0
H-bond acceptors
0
Rotatable bonds
0
TPSA (Ų)
0
Formal charge
0
XLogP3
1.4 PubChem
Complexity
7 PubChem
Stereocenters
None
Double-bond geometry
None specified
Point group
Cs of one 3D conformer with its hydrogens, by Athanor’s engine (as in the app)

Elemental analysis

  • C85.63%
  • H14.37%

Isotope pattern

100%42.0473.3%43.050

Each peak is a nominal mass with its abundance-weighted exact mass, as a percentage of the tallest, from IUPAC natural isotope abundances.

Computed from the structure with RDKit 2026.09 when this page was built, beside PubChem's own computed values from its record; where the two differ, both are shown.

Predicted

log P
1.19 Crippen (Wildman and Crippen 1999)
log S (water solubility)
-0.85 ESOL (Delaney 2004), log mol/L
Synthetic accessibility
3.01 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)

Drug-likeness: Lipinski’s rule of five

  • Molecular weight ≤ 500: 42.08
  • log P ≤ 5 (Crippen): 1.19
  • H-bond donors ≤ 5: 0
  • H-bond acceptors ≤ 10: 0

Passes all four rules.

¹³C NMR shifts, predicted

Predictions, not measurements; each names its method. A measured log P, where a source reports one, is under Physical properties.

Safety

Danger

Harmonized EU classification (CLP Annex VI). Source [7].

  • Flammable
  • Compressed gas
411
NFPA 704[5]
  • H220Extremely flammable gas

Precautionary statements: P203, P210, P222, P280, P377, P381, P403

View all classifications (4)
  • [7] Regulation (EC) No 1272/2008 of the European Parliament and of the Council · DangerH220
  • [8] European Chemicals Agency (ECHA)This chemical does not meet GHS hazard criteria for < 0.1% (2 of 2232) of reports.
  • [8] European Chemicals Agency (ECHA) · 2,232 reports · DangerH280
  • [5] Hazardous Substances Data Bank (HSDB) · DangerH220, H280

Exposure limits

  • TLV: 500 ppm as TWA; A4 (not classifiable as a human carcinogen)[3]
  • TLV-TWA (Time Weighted Average): 500 ppm [2005][4]

First aid

  • Eyes: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. Immediately transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop. Skin: Caution: Exposure of skin to compressed gases may result in freezing of the skin. Treatment for frostbite may be necessary.[1]
  • General First Aid: · Call 911 or emergency medical service. · Ensure that medical personnel are aware of the material(s) involved, take precautions to protect themselves and avoid contamination. · Move victim to fresh air if it can be done safely. · Administer oxygen if breathing is difficult. · If victim is not breathing: -- DO NOT perform mouth-to-mouth resuscitation; the victim may have ingested or inhaled the substance. -- If equipped and pulse detected, wash face and mouth, then give artificial respiration using a proper respiratory medical device (bag-valve mask, pocket mask equipped…[9]
  • General First Aid: · Call 911 or emergency medical service. · Ensure that medical personnel are aware of the material(s) involved, take precautions to protect themselves and avoid contamination. · Move victim to fresh air if it can be done safely. · Administer oxygen if breathing is difficult. · If victim is not breathing: -- DO NOT perform mouth-to-mouth resuscitation; the victim may have ingested or inhaled the substance. -- If equipped and pulse detected, wash face and mouth, then give artificial respiration using a proper respiratory medical device (bag-valve mask, pocket mask equipped…[9]
  • Fresh air, rest. Artificial respiration may be needed. Refer for medical attention.[3]

Storage

  • Fireproof. Cool.[3]
  • Keep container tightly closed in a dry and well-ventilated place. Contents under pressure. Storage class (TRGS 510): Gases[5]

Incompatibilities

  • Propylene ... Reacts vigorously with oxidizing materials. Under unusual conditions, eg, 96.8 MPa (995 atm) and 600 K, it explodes. It reacts violently with NO2, N2O4, and N2O. Explosions have been reported when liquid propylene contacts water at 315-348 K.[5]
  • A mixture under confinement in a glass pressure bottle at 20 °C polymerized explosively, the polymerization probably being initiated by access of light through the clear glass container. Such alkene-sulfur dioxide co-polymerizations will not occur above a ceiling temperature, different for each alkene.[5]
  • Explodes on contact with trifluoromethyl hypofluorite.[5]
  • Explosive polymerization is initiated by lithium nitrate+sulfur dioxide.[5]

Safety data sheets on the supplier’s page: ChemoSapiens, CymitQuimica, A2B Chem.

Always read the supplier’s safety data sheet before working with it.

Spectra

Experimental spectra held by these sources; each link opens the source's own record.

Literature

Reading PubChem, OpenAlex and GSRS…

Bioactivity

Reading ChEMBL…

References

  1. [1]CAMEO Chemicals · Public domain (NOAA) · via PubChem · retrieved 2026-10-14
  2. [2]EPA Chemical Data Reporting (CDR) · Public domain (US EPA) · via PubChem · retrieved 2026-10-14
  3. [3]ILO-WHO International Chemical Safety Cards (ICSCs) · CC BY 4.0 · via PubChem · retrieved 2026-10-14
  4. [4]Occupational Safety and Health Administration (OSHA) · Public domain (US DOL) · via PubChem · retrieved 2026-10-14
  5. [5]Hazardous Substances Data Bank (HSDB) · Public domain (US NLM) · via PubChem · retrieved 2026-10-14
  6. [6]PAC Chemical Database, U.S. Department of Energy · Public domain (US DOE) · via PubChem · retrieved 2026-10-14
  7. [7]Regulation (EC) No 1272/2008 of the European Parliament and of the Council · EU reuse policy, CC BY 4.0 · via PubChem · retrieved 2026-10-14
  8. [8]European Chemicals Agency (ECHA) · ECHA legal notice: reuse with acknowledgement · via PubChem · retrieved 2026-10-14
  9. [9]Emergency Response Guidebook (ERG) · Public domain (US DOT) · via PubChem · retrieved 2026-10-14
  10. [10]NMRShiftDB · Linked only · via PubChem · retrieved 2026-10-14
  11. [11]SpectraBase · Linked only · via PubChem · retrieved 2026-10-14
  12. [12]MassBank of North America (MoNA) · CC BY 4.0 · via PubChem · retrieved 2026-10-14
  13. [13]NIST Mass Spectrometry Data Center · Linked only · via PubChem · retrieved 2026-10-14
  14. [14]MassBank Europe · Linked only · via PubChem · retrieved 2026-10-14
  15. ·Calculated values: computed by Athanor with RDKit 2026.09 from the structure.
  16. ·Literature on PubChem

Data last updated 2026-10-14.