Pelargonic acid

Pelargonic acid
Names
Preferred IUPAC name
Nonanoic acid
Other names
Nonoic acid; nonylic acid; 1-octanecarboxylic acid; C9:0 (lipid numbers)
Identifiers
3D model (JSmol)
1752351
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.003.574 Edit this at Wikidata
EC Number
  • 203-931-2
185341
KEGG
UNII
  • InChI=1S/C9H18O2/c1-2-3-4-5-6-7-8-9(10)11/h2-8H2,1H3,(H,10,11) checkY
    Key: FBUKVWPVBMHYJY-UHFFFAOYSA-N checkY
  • InChI=1/C9H18O2/c1-2-3-4-5-6-7-8-9(10)11/h2-8H2,1H3,(H,10,11)
    Key: FBUKVWPVBMHYJY-UHFFFAOYAF
  • CCCCCCCCC(=O)O
Properties
C9H18O2
Molar mass 158.241 g/mol
Appearance Clear to yellowish oily liquid
Density 0.900 g/cm3
Melting point 12.5 °C (54.5 °F; 285.6 K)
Boiling point 254 °C (489 °F; 527 K)
Critical point (T, P) 439 °C (712 K), 2.35 MPa
0.3 g/L
Acidity (pKa)
  • 4.96
  • 1.055 at 2.06–2.63 K (−271.09 – −270.52 °C; −455.96 – −454.94 °F)
  • 1.53 at −191 °C (−311.8 °F; 82.1 K)
1.4322
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
 Corrosive
GHS labelling:
GHS05: CorrosiveGHS07: Exclamation mark
Warning
H315, H319, H412
P264, P273, P280, P302+P352, P305+P351+P338, P321, P332+P313, P337+P313, P362, P501
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
3
1
0
Flash point 114 °C (237 °F; 387 K)
405 °C (761 °F; 678 K)
Related compounds
Related compounds
 Caprylic acid, Capric acid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Pelargonic acid, also called nonanoic acid, is an organic compound with structural formula CH3(CH2)7CO2H. It is a nine-carbon fatty acid. Nonanoic acid is a colorless oily liquid with an unpleasant, rancid odor. It is nearly insoluble in water, but very soluble in organic solvents. The esters and salts of pelargonic acid are called pelargonates or nonanoates.

The acid is named after the pelargonium plant, since oil from its leaves contains esters of the acid. In the food industry, pelargonic acid is used as a flavouring agent and food additive. It is commonly used as a non-selective contact herbicide.

Preparation

Pelargonic acid, similarly to azelaic acid, is produced industrially by the ozonolysis of oleic acid.

CH3(CH2)7CH=CH(CH2)7CO2H + O3 → CH3(CH2)7CO2H + HO2C(CH2)7CO2H

Alternatively, pelargonic acid can be produced in a two-step process beginning with coupled dimerization and hydroesterification of 1,3-butadiene. This step produces a doubly unsaturated C9-ester, which can be hydrogenated to produce esters of pelargonic acid.

2 CH2=CHCH=CH2 + CO + CH3OH → CH2=CH(CH2)3CH=CHCH2CO2CH3
CH2=CH(CH2)3CH=CHCH2CO2CH3 + 2 H2 → CH3(CH2)7CO2CH3

A laboratory preparation involves permanganate oxidation of 1-decene.

Occurrence and uses

The Pelargonium plant after which the acid is named

Pelargonic acid is found naturally in many species of animals and plants including numerous fruits and vegetables such as apples, grapes, oranges, potatoes and also milk. The esters occur in the oil of Pelargonium. It was first isolated in 1845 by Austrian chemist H. Pless from the essential oil of Pelargonium roseum. It was officially synthesized and named by Joseph Redtenbacher. Pelargonic acid was also discovered in several essential oils of French lavender, hops and rose.

The U.S. Food and Drug Administration has approved pelargonic acid as a synthetic food flavouring agent, a production aid and sanitizer to be used in contact with food and as an ingredient used commercially to peel fruits and vegetables (up to 1%). Synthetic esters of pelargonic acid, such as methyl pelargonate, are used as flavourings. Pelargonic acid is used in the preparation of plasticizers and lacquers. The derivative 4-nonanoylmorpholine is an ingredient in some pepper sprays. Esters of pelargonic acid are precursors to lubricants.

Pelargonic acid is used in household and industrial cleaning products due to its ability to dissolve and remove fatty, greasy and oily substances. In the cosmetic industry, pelargonic acid is utilized for its antimicrobial properties and is incorporated into shampoo and skin care products.

Herbicide

As a contact herbicide, pelargonic acid acts through rapid membrane disruption. From an environmental perspective its low accumulation and rapid degradation in soil make it a promising alternative for sustainable weed management. In 1995, Mycogen Corporation introduced the first pelargonic acid herbicide under the brand name Scythe, containing 57% pelargonic acid.

In the United States, pelargonic acid is not a certified organic herbicide. This is because it is manufactured using a synthetic process including ozonation which makes the material ineligible for use in organic agriculture under United States Department of Agriculture (USDA) criteria.

Ammonium pelargonate (also known as ammonium nonanoate), is a naturally derived compound created by combining pelargonic acid with ammonia. It is commonly used as a non-selective contact herbicide, for a quick burn-down effect in the control of weeds in turfgrass. It works by causing leaks in plant cell membranes, allowing chlorophyll molecules to escape the chloroplast. Under sunlight, these misplaced molecules cause immense oxidative damage to the plant. Ammonium pelargonate is approved for organic use by the USDA as it qualifies as an ammoniated soap salt of a fatty acid, whereas standalone pelargonic acid is not a soap and thus not eligible for use in USDA organic production.

In 2026, the European Commission renewed approval of pelargonic acid as an active substance in plant protection products.

Pelargonic acid is sometimes used in combination with flazasulfuron or maleic hydrazide.

The methyl form and ethylene glycol pelargonate act as nematicides against Meloidogyne javanica on Solanum lycopersicum, and the methyl against Heterodera glycines and M. incognita on Glycine max.

Pharmacological effects

Pelargonic acid may be more potent than valproic acid in treating seizures. Moreover, in contrast to valproic acid, pelargonic acid exhibited no effect on HDAC inhibition, suggesting that it is unlikely to show HDAC inhibition-related teratogenicity.

Toxicology

It is safe for humans to consume foods containing small amounts of pelargonic acid. Ingesting or inhaling pelargonic acid in small amounts has no known toxic effects. No risks to humans or the environment are expected when herbicide products containing pelargonic acid are used according to label directions.

Tests have revealed a low toxicity risk to birds and mammals.

See also

Notes

  1. ↑ The Environmental Protection Agency have stated that "pelargonic acid is naturally present at levels up to 224 parts per billion (ppb) in apples, 385 ppm in the skin of grapes, and 143 ppm in grape pulp. It is present in a number of other foods as well."

References

  1. ↑ Lide, D. R. (Ed.) (1990). CRC Handbook of Chemistry and Physics (70th Edn.). Boca Raton (FL):CRC Press.
  2. ↑ Anneken, David J.; Both, Sabine; Christoph, Ralf; Fieg, Georg; Steinberner, Udo; Westfechtel, Alfred (2006). "Fatty Acids". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a10_245.pub2. ISBN 978-3-527-30385-4.
  3. ↑ J. Grub; E. Löser (2012). "Butadiene". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a04_431.pub2. ISBN 978-3-527-30673-2.
  4. ↑ Lee, Donald G.; Lamb, Shannon E.; Chang, Victor S. (1981). "Carboxylic Acids from the Oxidation of Terminal Alkenes by Permanganate: Nonadecanoic Acid". Organic Syntheses. 60: 11. doi:10.15227/orgsyn.060.0011.
  5. ↑ "Pelargonic Acid" (PDF). ICF International for the USDA National Organic Program. 2006.
  6. ↑ "Herbicides based on pelargonic acid: Herbicides of the bioeconomy" (PDF). Society of Chemical Industry. 2019.
  7. ↑ "Pelargonic Acid (Nonanoic Acid); Exemption from the Requirement of a Pesticide Tolerance". Federal Register. 2003.
  8. 1 2 "Biobased herbicides based on pelargonic acid" (PDF). Chemistry Today. 2019.
  9. 1 2 "PETITION FOR THE LISTING OF PELARGONIC ACID AND RELATED C6-C12 FATTY ACIDS ON THE USDA NATIONAL LIST OF ALLOWED AND PROHIBITED SUBSTANCES" (PDF). USDA National Organic Program. 2005.
  10. 1 2 3 4 "EPA Pesticide Fact Sheet: Pelargonic Acid". National Technical Reports Library. 1998.
  11. 1 2 3 4 "Pelargonic Acid (217500) Fact Sheet" (PDF). U.S. Environmental Protection Agency. 2000.
  12. ↑ "Pelargonic Acid". Ataman Chemicals. 2026.
  13. ↑ Johnson, Wilbur; Heldreth, Bart (2011). "Final Report of the Cosmetic Ingredient Review Expert Panel on the Safety Assessment of Pelargonic Acid (Nonanoic Acid) and Nonanoate Esters". International Journal of Toxicology. 30 (6): 228S–269S. doi:10.1177/1091581811428980. PMID 22247237.
  14. 1 2 3 Preisler AC, Campos EVR, Takeshita V, Rodrigues JS, de Freitas ASM, Cintra Cardoso B, Battaglini LD, Fraceto LF (2026). "Pelargonic Acid: From Historical Uses to Future Perspectives in Sustainable Agriculture". J Agric Food Chem. 74 (12): 9903–9915. Bibcode:2026JAFC...74.9903P. doi:10.1021/acs.jafc.5c14438. PMC 13047689. PMID 41774570.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  15. ↑ "Going natural: Effective weed control in squash with pelargonic acid". United States Department of Agriculture. 2026.
  16. 1 2 Baker, Brian (2021). "Pelargonic Acid". OMRI.
  17. ↑ Lederer, Barbara; Fujimori, Takane; Tsujino, Yasuko; Wakabayashi, Ko; Böger, Peter (November 2004). "Phytotoxic activity of middle-chain fatty acids II: peroxidation and membrane effects". Pesticide Biochemistry and Physiology. 80 (3): 151–156. Bibcode:2004PBioP..80..151L. doi:10.1016/j.pestbp.2004.06.010.
  18. ↑ "Organic herbicide update". United States Department of Agriculture. 2026.
  19. ↑ "Active substance: Pelargonic acid (CAS 112-05-0)". European Commission. 2026.
  20. ↑ "EU renews approval of pelargonic acid as pesticide active substance until 2041". Lovguiden. 2026.
  21. ↑ Poiger, T., Müller, J., Kasteel, R. (2024). "Degradation and sorption of the herbicide pelargonic acid in subsoils below railway tracks compared to a range of topsoils". Environ Sci Eur. 36 4. doi:10.1186/s12302-023-00825-1.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  22. ↑ "Ultima" (PDF). Pesticide Registration and Control Divisions. 2019.
  23. ↑ "Pelargonic Acid". Neudorff. 2026.
  24. ↑ Chitwood, David J. (2002). "Phytochemical Based Strategies for Nematode Control". Annual Review of Phytopathology. 40 (1). Annual Reviews: 221–249. Bibcode:2002AnRvP..40..221C. doi:10.1146/annurev.phyto.40.032602.130045. ISSN 0066-4286. PMID 12147760. p. 229.
  25. 1 2 Chang, P.; Terbach, N.; Plant, N.; Chen, P. E.; Walker, M. C.; Williams, R. S. (2013). "Seizure control by ketogenic diet-associated medium chain fatty acids". Neuropharmacology. 69: 105–114. doi:10.1016/j.neuropharm.2012.11.004. PMC 3625124. PMID 23177536.
  26. ↑ "Pelargonic acid". BPDB: Biopesticides DataBase. 2026.
  27. ↑ European Food Safety Authority (EFSA); Álvarez F, Arena M, Auteri D, Leite SB, Binaglia M, Castoldi AF, Chiusolo A, Colagiorgi A, Colas M, Crivellente F, De Lentdecker C, De Magistris I, Egsmose M, Fait G, Ferilli F, Broussard MF, Santonja GG, Gouliarmou V, Halling K, Ippolito A, Istace F, Jarrah S, Kardassi D, Kienzler A, Lanzoni A, Lava R, Leuschner R, Linguadoca A, Louisse J, Lythgo C, Magrans O, Mangas I, Mioč A, Miron I, Molnar T, Padovani L, Padricello V, Panzarea M, Parra Morte JM, Piti A, Rizzuto S, Santos M, Serafimova R, Sharp R, Szentes C, Theobald A, Tiramani M, Vianello G, Villamar-Bouza L. (2025). "Updated peer review of the pesticide risk assessment of the active substance pelargonic acid (nonanoic acid)". EFSA J. 23 (6) e9408. doi:10.2903/j.efsa.2025.9408. PMC 12177548. PMID 40538833.{{cite journal}}: CS1 maint: multiple names: authors list (link)