Oleic acid
Athanor · official
C18H34O2 · 282.5 g/mol
IUPAC name: (Z)-octadec-9-enoic acid
Also called C18:1, omega-9, olive oil, (9Z)-octadec-9-enoic acid, oleate
WarningCauses skin irritation · Causes serious eye irritationNames and identifiers
- IUPAC name
- (Z)-octadec-9-enoic acid
- Synonyms
- C18:1, omega-9, olive oil
+ 40 more
(9Z)-octadec-9-enoic acid, oleate, cis-9-Octadecenoic acid, (Z)-Octadec-9-enoic acid, Wecoline OO, Vopcolene 27, cis-Oleic acid, Glycon wo, Glycon RO, Oelsauere, Pamolyn 100, Elaidoic acid, Groco 5l, Oleinic acid, Groco 2, Groco 4, Groco 6, Tego-oleic 130, Emersol 211, Pamolyn, cis-Octadec-9-enoic acid, Industrene 105, Industrene 205, Industrene 206, Z-9-Octadecenoic acid, 9-Octadecenoic acid (Z)-, L'Acide oleique, Emersol 210, Emersol 213, 9Z-Octadecenoic acid, Emersol 6321, Extraolein 90, Oleine 7503, Emersol 205, Emersol 233LL, 9-Octadecenoic acid (9Z)-, 9-Octadecenoic acid, (Z)-, Priolene 6906, White oleic acid, Hy-phi 1055
- Molecular formula
- C18H34O2
- Empirical formula
- C9H17O
- Molecular weight
- 282.5 g/mol
- Exact mass
- 282.25588
- CAS number
- 112-80-1
- PubChem CID
- 445639
- Canonical SMILES
- CCCCCCCCC=CCCCCCCCC(=O)O
- Isomeric SMILES
- CCCCCCCC/C=C\CCCCCCCC(=O)O
- InChI
- InChI=1S/C18H34O2/c1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18(19)20/h9-10H,2-8,11-17H2,1H3,(H,19,20)/b10-9-
- InChIKey
- ZQPPMHVWECSIRJ-KTKRTIGZSA-N
- Molfile
Names, InChI and the identifiers from PubChem, retrieved 2026-10-14.
Physical properties
TemperaturePressureDensity
- Appearance
- Oleic acid is a colorless to pale yellow liquid with a mild odor. Floats on water. (USCG, 1999)[1]
5 values
From CAMEO Chemicals, the most authoritative source here.
Value As written Source –shown Oleic acid is a colorless to pale yellow liquid with a mild odor. Floats on water. (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. – Other Solid; CBI; Liquid; Wet Solid; Liquid; Liquid; Other Solid [2] EPA Chemical Data Reporting (CDR) – COLOURLESS LIQUID. TURNS YELLOW-TO-BROWN ON EXPOSURE TO AIR. [3] ILO-WHO International Chemical Safety Cards (ICSCs) – YELLOWISH, OILY LIQUID [4] Hazardous Substances Data Bank (HSDB)cites Patty, F. (ed.). Industrial Hygiene and Toxicology: Volume II: Toxicology. 2nd ed. New York: Interscience Publishers, 1963., p. 1791 – WATER-WHITE LIQUID [4] Hazardous Substances Data Bank (HSDB)cites Osol, A. and J.E. Hoover, et al. (eds.). Remington's Pharmaceutical Sciences. 15th ed. Easton, Pennsylvania: Mack Publishing Co., 1975., p. 1247 - Odor
- PECULIAR LARD-LIKE ODOR[4]
- Melting point
- 13.4 °C[3]
2 values
Sources disagree; from ILO-WHO International Chemical Safety Cards (ICSCs), the most authoritative.
Value As written Source 16.3 °C 61.3 °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. 13.4 °Cshown 13.4 °C [3] ILO-WHO International Chemical Safety Cards (ICSCs) - Boiling point
- 286 °C (547 °F) at 100 mmHg (NTP, 1992)[1]
- Density
- Relative density (water = 1): 0.89[3]
3 values
2 of 2 sources agree on it (most common value).
Value As written Source – 0.89 at 77 °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. –shown Relative density (water = 1): 0.89 [3] ILO-WHO International Chemical Safety Cards (ICSCs) – ~0.895 @25 °C [5] PAC Chemical Database, U.S. Department of Energy - Solubility in water
- Solubility in water: none[3]
3 values
From ILO-WHO International Chemical Safety Cards (ICSCs), the most authoritative source here.
Value As written Source – Insoluble (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. – Miscible with methanol [4] Hazardous Substances Data Bank (HSDB)cites Lide, D.R., G.W.A. Milne (eds.). Handbook of Data on Organic Compounds. Volume I. 3rd ed. CRC Press, Inc. Boca Raton ,FL. 1994., p. V4: 3693 –shown Solubility in water: none [3] ILO-WHO International Chemical Safety Cards (ICSCs) - log P
- 7.73 (estimated)[3]
2 values
2 of 2 sources agree on it (most common value).
Value As written Source – log Kow = 7.64 [4] Hazardous Substances Data Bank (HSDB)cites Sangster J; LOGKOW Databank. Sangster Res Lab Montreal Quebec, Canada (1994) –shown 7.73 (estimated) [3] ILO-WHO International Chemical Safety Cards (ICSCs) - pKa
- pKa = 5.02 in aqueous solution at 25 °C[4]
- Vapor pressure
- 5.46 × 10⁻⁷ mmHg at 25 °C[4]
2 values
Sources disagree; from Hazardous Substances Data Bank (HSDB), the most authoritative.
Value As written Source 5.46e-7 mmHgshown 5.46X10-7 mm Hg at 25 °C [4] 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. 1 mmHg 1 [mm Hg] @176.5 °C [5] PAC Chemical Database, U.S. Department of Energy - Flash point
- 189 °C c.c.[3]
4 values
3 of 3 sources agree on it (most common value).
Value As written Source 189 °C 372 °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. 199 to 218 °C 390-425 °F (open cup) [4] Hazardous Substances Data Bank (HSDB)cites U.S. Coast Guard, Department of Transportation. CHRIS - Hazardous Chemical Data. Volume II. Washington, D.C.: U.S. Government Printing Office, 1984-5. 189 °C 372 °F (189 °C) (closed cup) [4] Hazardous Substances Data Bank (HSDB)cites Fire Protection Guide to Hazardous Materials. 13 ed. Quincy, MA: National Fire Protection Association, 2002., p. 325-94 189 °Cshown 189 °C c.c. [3] ILO-WHO International Chemical Safety Cards (ICSCs) - Autoignition temperature
- 363 °C[3]
3 values
3 of 3 sources agree on it (most common value).
Value As written Source 363 °C 685 °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. 363 °C 685 °F (363 °C) [4] Hazardous Substances Data Bank (HSDB)cites Fire Protection Guide to Hazardous Materials. 13 ed. Quincy, MA: National Fire Protection Association, 2002., p. 325-94 363 °Cshown 363 °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
- 20
- Rings
- 0
- Aromatic rings
- 0
- Fraction sp³ carbons (Fsp3)
- 0.83
- H-bond donors
- 1
- H-bond acceptors
- 1 computed here · PubChem 2
- Rotatable bonds
- 15
- TPSA (Ų)
- 37.3
- Formal charge
- 0
- XLogP3
- 6.5 PubChem
- Complexity
- 234 PubChem
- Stereocenters
- None
- Double-bond geometry
- C9=C10: Z
- Point group
- C1 of one 3D conformer with its hydrogens, by Athanor’s engine (as in the app)
Elemental analysis
- C76.54%
- H12.13%
- O11.33%
Isotope pattern
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
- 6.11 Crippen (Wildman and Crippen 1999)
- log S (water solubility)
- -4.45 ESOL (Delaney 2004), log mol/L
- Synthetic accessibility
- 2.03 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)
Drug-likeness: Lipinski’s rule of five
- Molecular weight ≤ 500: 282.47
- log P ≤ 5 (Crippen): 6.11
- H-bond donors ≤ 5: 1
- H-bond acceptors ≤ 10: 1
Breaks 1 of the 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
Warning
Most widely reported: 2,091 company reports to ECHA. Source [6].
- Harmful or irritant
- H315Causes skin irritation (31.5% of reports)
- H319Causes serious eye irritation (22% of reports)
Precautionary statements: P264, P264+P265, P280, P302+P352, P305+P351+P338, P321, P332+P317, P337+P317, P362+P364
View all classifications (2)
- [6] European Chemicals Agency (ECHA)This chemical does not meet GHS hazard criteria for 65.4% (1368 of 2091) of all reports.
- [6] European Chemicals Agency (ECHA) · 2,091 reports · WarningH315, H319
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: Immediately flood affected skin with water while removing and isolating all contaminated clothing.[1]
- Fresh air, rest.[3]
- Rinse and then wash skin with water and soap.[3]
- First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.[3]
Incompatibilities
- The improved preparation of 1,4-octadecanolactone involves heating oleic acid (or other C18 acids) with 70% perchloric acid to 115 °C. This is considered to be a potentially dangerous method.[4]
- Shortly after mixing (aluminum and oleic acid), an explosion occurred, but this could not be repeated. The acid may have been peroxidized.[4]
- Potentially dangerous reaction with perchloric acid and heat.[4]
Safety data sheets on the supplier’s page: Angene Chemical, Sigma-Aldrich, AiFChem, an XtalPi Company.
Always read the supplier’s safety data sheet before working with it.
Spectra
- NMRHazardous Substances Data Bank (HSDB)
- 1H NMRHuman Metabolome Database (HMDB) (Varian · 500 MHz · CDCl3) · SpectraBase (Varian A-60)
- 13C NMRHazardous Substances Data Bank (HSDB) · SpectraBase
- 1H-13C NMRHuman Metabolome Database (HMDB) (Bruker · 600 MHz · CDCl3)
- GC-MSHuman Metabolome Database (HMDB) (EI-B · positive) · Human Metabolome Database (HMDB) (GC-EI-TOF · positive) · Human Metabolome Database (HMDB) (GC-MS) · Human Metabolome Database (HMDB) (GC-EI-TOF (Pegasus III TOF-MS system, Leco; GC 6890, Agilent Technologies) · Positive) · Human Metabolome Database (HMDB) (GC-MS) · MassBank Europe (Pegasus III TOF-MS system, Leco; GC 6890, Agilent Technologies · GC-EI-TOF · POSITIVE)
- MS-MSHuman Metabolome Database (HMDB) (Negative) · Human Metabolome Database (HMDB) (Negative) · Human Metabolome Database (HMDB) (Positive) · Human Metabolome Database (HMDB) (Positive) · Human Metabolome Database (HMDB) (Negative) · Human Metabolome Database (HMDB) (Positive)
- LC-MSMassBank Europe (Agilent 6560 QTOF · LC-ESI-QTOF · NEGATIVE) · MassBank Europe (Agilent 6560 QTOF · LC-ESI-QTOF · NEGATIVE) · MassBank Europe (maXis plus UHR-ToF-MS, Bruker Daltonics · LC-ESI-QTOF · NEGATIVE) · MassBank Europe (maXis plus UHR-ToF-MS, Bruker Daltonics · LC-ESI-QTOF · NEGATIVE) · MassBank Europe (Bruker impact HD · LC-ESI-QTOF · NEGATIVE) · MassBank Europe (Bruker impact HD · LC-ESI-QTOF · NEGATIVE)
- Other MSHazardous Substances Data Bank (HSDB) · MassBank Europe (Unknown · EI-B · POSITIVE) · MassBank Europe (JMS-HX/HX 110A, JEOL · FAB-EBEB · NEGATIVE) · MassBank of North America (MoNA) (Orbitrap · positive) · MassBank of North America (MoNA) (TQD, Waters · Flow-injection QqQ/MS · ESI) · MassBank of North America (MoNA) (TQD, Waters · Flow-injection QqQ/MS · ESI)
- UVHazardous Substances Data Bank (HSDB)
- IRHazardous Substances Data Bank (HSDB)
- FTIRSpectraBase (BETWEEN SALTS)
- ATR-IRSpectraBase (ATR-Neat)
- Vapor Phase IRSpectraBase (DIGILAB FTS-14 · Vapor Phase)
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]CAMEO Chemicals · Public domain (NOAA) · via PubChem · retrieved 2026-10-14
- [2]EPA Chemical Data Reporting (CDR) · Public domain (US EPA) · via PubChem · retrieved 2026-10-14
- [3]ILO-WHO International Chemical Safety Cards (ICSCs) · CC BY 4.0 · via PubChem · retrieved 2026-10-14
- [4]Hazardous Substances Data Bank (HSDB) · Public domain (US NLM) · via PubChem · retrieved 2026-10-14
- [5]PAC Chemical Database, U.S. Department of Energy · Public domain (US DOE) · via PubChem · retrieved 2026-10-14
- [6]European Chemicals Agency (ECHA) · ECHA legal notice: reuse with acknowledgement · via PubChem · retrieved 2026-10-14
- [7]Human Metabolome Database (HMDB) · Linked only · via PubChem · retrieved 2026-10-14
- [8]SpectraBase · Linked only · via PubChem · retrieved 2026-10-14
- [9]MassBank Europe · Linked only · via PubChem · retrieved 2026-10-14
- [10]MassBank of North America (MoNA) · CC BY 4.0 · via PubChem · retrieved 2026-10-14
- [11]NIST Mass Spectrometry Data Center · Linked only · via PubChem · retrieved 2026-10-14
- ·Calculated values: computed by Athanor with RDKit 2026.09 from the structure.
- ·Literature on PubChem
Data last updated 2026-10-14.