Nonanoic acid (C9H18O2): structure, properties and hazards

Names and identifiers

IUPAC name: nonanoic acid
Synonyms: pelargonic acid, C9:0, nonanoate
+ 38 more
Pelargonic acid, n-Nonanoic acid, Nonoic acid, Nonylic acid, Pelargic acid, 1-Octanecarboxylic acid, n-Nonylic acid, n-Nonoic acid, Pelargon, Hexacid C-9, Cirrasol 185A, Emfac 1202, 1-Octanecarboxyic acid, FEMA No. 2784, DTXSID3021641, CHEBI:29019, 97SEH7577T, NSC-62787, DTXCID901641, NSC62787, NSC-65450, NSC-65455, RefChem:166452, 203-931-2, pergonic acid, 1-nonanoic acid, MFCD00004433, Nonansaeure, Pelargonsaeure, NSC 62787, CH3-[CH2]7-COOH, N-Pelargonicacid, pergonate, n-nonanoate, FA 9:0, 1-nonanoate, 1-octanecarboxylate, Pelargon [Russian]
Molecular formula: C₉H₁₈O₂
Empirical formula: C₉H₁₈O₂
Molecular weight: 158.24 g/mol
Exact mass: 158.13068
CAS number: 112-05-0
PubChem CID: 8158
Canonical SMILES: CCCCCCCCC(=O)O
Isomeric SMILES: CCCCCCCCC(=O)O
InChI: InChI=1S/C9H18O2/c1-2-3-4-5-6-7-8-9(10)11/h2-8H2,1H3,(H,10,11)
InChIKey: FBUKVWPVBMHYJY-UHFFFAOYSA-N
Molfile

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

Physical properties

TemperaturePressureDensity

Appearance: Yellowish oil[2]
2 values
From Hazardous Substances Data Bank (HSDB), the most authoritative source here.
Value As written Source
– Liquid; Large Crystals [1] EPA Chemical Data Reporting (CDR)
–shown Yellowish oil [2] 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. 841
Odor: Slight odor[2]
2 values
From Hazardous Substances Data Bank (HSDB), the most authoritative source here.
Value As written Source
– FATTY ODOR [2] Hazardous Substances Data Bank (HSDB)cites Fenaroli's Handbook of Flavor Ingredients. Volume 2. Edited, translated, and revised by T.E. Furia and N. Bellanca. 2nd ed. Cleveland: The Chemical Rubber Co., 1975., p. 433
–shown Slight odor [2] 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. 841
Boiling point: Boiling point = 255.6 °C[2]
2 values
Sources disagree; from Hazardous Substances Data Bank (HSDB), the most authoritative.
Value As written Source
255.6 °Cshown Boiling point = 255.6 °C [2] 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. 841
254 °C 254 °C @760 [mm Hg] [3] PAC Chemical Database, U.S. Department of Energy
Density: 0.9055 @ 20°C[3]
Solubility in water: In water, 284 mg/L at 30 °C[2]
2 values
From Hazardous Substances Data Bank (HSDB), the most authoritative source here.
Value As written Source
– 1:8 IN 50% ALCOHOL; 1:3 IN 60% ALCOHOL; INSOL IN WATER; SOL IN MOST ORG SOLVENTS [2] Hazardous Substances Data Bank (HSDB)cites Fenaroli's Handbook of Flavor Ingredients. Volume 2. Edited, translated, and revised by T.E. Furia and N. Bellanca. 2nd ed. Cleveland: The Chemical Rubber Co., 1975., p. 433
–shown In water, 284 mg/L at 30 °C [2] Hazardous Substances Data Bank (HSDB)cites Riddick, J.A., W.B. Bunger, Sakano T.K. Techniques of Chemistry 4th ed., Volume II. Organic Solvents. New York, NY: John Wiley and Sons., 1985., p. 375
log P: log Kow = 3.42[2]
pKa: pKa = 4.95 at 25 °C[2]
Vapor pressure: 1.65 × 10⁻³ mmHg at 25 °C[2]
2 values
2 of 2 sources agree on it (most common value).
Value As written Source
0.00165 mmHgshown 1.65X10-3 mm Hg at 25 °C [2] 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.
0.00165 mmHg 0.00165 [mm Hg] @25 °C [3] PAC Chemical Database, U.S. Department of Energy
Flash point: 133 °C (open cup)[2]
Viscosity: Reported, but no value passed the checks.
The value and why
8.08 mPa.sec at 20 °C (could not be read; source [2])

Value	As written	Source
–	Liquid; Large Crystals	[1] EPA Chemical Data Reporting (CDR)
–shown	Yellowish oil	[2] 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. 841

Value	As written	Source
–	FATTY ODOR	[2] Hazardous Substances Data Bank (HSDB)cites Fenaroli's Handbook of Flavor Ingredients. Volume 2. Edited, translated, and revised by T.E. Furia and N. Bellanca. 2nd ed. Cleveland: The Chemical Rubber Co., 1975., p. 433
–shown	Slight odor	[2] 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. 841

Value	As written	Source
255.6 °Cshown	Boiling point = 255.6 °C	[2] 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. 841
254 °C	254 °C @760 [mm Hg]	[3] PAC Chemical Database, U.S. Department of Energy

Value	As written	Source
–	1:8 IN 50% ALCOHOL; 1:3 IN 60% ALCOHOL; INSOL IN WATER; SOL IN MOST ORG SOLVENTS	[2] Hazardous Substances Data Bank (HSDB)cites Fenaroli's Handbook of Flavor Ingredients. Volume 2. Edited, translated, and revised by T.E. Furia and N. Bellanca. 2nd ed. Cleveland: The Chemical Rubber Co., 1975., p. 433
–shown	In water, 284 mg/L at 30 °C	[2] Hazardous Substances Data Bank (HSDB)cites Riddick, J.A., W.B. Bunger, Sakano T.K. Techniques of Chemistry 4th ed., Volume II. Organic Solvents. New York, NY: John Wiley and Sons., 1985., p. 375

Value	As written	Source
0.00165 mmHgshown	1.65X10-3 mm Hg at 25 °C	[2] 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.
0.00165 mmHg	0.00165 [mm Hg] @25 °C	[3] PAC Chemical Database, U.S. Department of Energy

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: 11
Rings: 0
Aromatic rings: 0
Fraction sp³ carbons (Fsp3): 0.89
H-bond donors: 1
H-bond acceptors: 1 computed here · PubChem 2
Rotatable bonds: 7
TPSA (Å²): 37.3
Formal charge: 0
XLogP3: 3.5 PubChem
Complexity: 99 PubChem
Stereocenters: None
Double-bond geometry: None specified
Point group: C1 of one 3D conformer with its hydrogens, by Athanor’s engine (as in the app)

Elemental analysis

C68.31%
H11.47%
O20.22%

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: 2.82 Crippen (Wildman and Crippen 1999)
log S (water solubility): -2.14 ESOL (Delaney 2004), log mol/L
Synthetic accessibility: 1.51 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)

Drug-likeness: Lipinski’s rule of five

Molecular weight ≤ 500: 158.24
log P ≤ 5 (Crippen): 2.82
H-bond donors ≤ 5: 1
H-bond acceptors ≤ 10: 1

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

Warning

Harmonized EU classification (CLP Annex VI). Source [4].

Harmful or irritant

H315Causes skin irritation
H319Causes serious eye irritation
H412Harmful to aquatic life with long lasting effects

Precautionary statements: P264, P264+P265, P273, P280, P302+P352, P305+P351+P338, P321, P332+P317, P337+P317, P362+P364, P501

View all classifications (2)

[4] Regulation (EC) No 1272/2008 of the European Parliament and of the Council · WarningH315, H319, H412
[5] European Chemicals Agency (ECHA) · 2,504 reports · DangerH314, H315, H318, H319, H412

Storage

Do not contaminate water, food, or feed by storage... . Keep conatiner tightly sealed when not in use. Store only in original container in a dry place inaccessible to children and pets. (scythe herbicide (57% pelargonic acid))[2]

Safety data sheets on the supplier’s page: Aladdin Scientific, Enamine, abcr GmbH.

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]EPA Chemical Data Reporting (CDR) · Public domain (US EPA) · via PubChem · retrieved 2026-10-14
[2]Hazardous Substances Data Bank (HSDB) · Public domain (US NLM) · via PubChem · retrieved 2026-10-14
[3]PAC Chemical Database, U.S. Department of Energy · Public domain (US DOE) · via PubChem · retrieved 2026-10-14
[4]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
[5]European Chemicals Agency (ECHA) · ECHA legal notice: reuse with acknowledgement · via PubChem · retrieved 2026-10-14
[6]NMRShiftDB · Linked only · 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.

Similar structures

Tanimoto similarity on Morgan fingerprints (radius 2) with RDKit 2026.09, at least 45%.