Hexanoic acid, also known as caproic acid, is the carboxylic acid derived from hexane with the chemical formula CH
4COOH. It is a colorless oily liquid with an odor that is fatty, cheesy, waxy, and like that of goats or other barnyard animals. It is a fatty acid found naturally in various animal fats and oils, and is one of the chemicals that give the decomposing fleshy seed coat of the ginkgo its characteristic unpleasant odor. It is also one of the components of vanilla. The primary use of hexanoic acid is in manufacture of its esters for artificial flavors, and in the manufacture of hexyl derivatives, such as hexylphenols. Salts and esters of hexanoic acid are known as hexanoates or caproates.
Caproic acid; n-Caproic acid; C6:0 (Lipid numbers)
3D model (JSmol)
CompTox Dashboard (EPA)
|Molar mass||116.160 g·mol−1|
|Melting point||−3.4 °C (25.9 °F; 269.8 K)|
|Boiling point||205.8 °C (402.4 °F; 478.9 K)|
|1.082 g/100 mL|
|Solubility||soluble in ethanol, ether|
Refractive index (nD)
|NFPA 704 (fire diamond)|
|Flash point||103 °C (217 °F; 376 K)|
|380 °C (716 °F; 653 K)|
|Lethal dose or concentration (LD, LC):|
LD50 (median dose)
|3000 mg/kg (rat, oral)|
|Pentanoic acid, Heptanoic acid|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Caproic, caprylic, and capric acids (capric is a crystal- or wax-like substance, whereas the other two are mobile liquids) are not only used for the formation of esters, but also commonly used "neat" in: butter, milk, cream, strawberry, bread, beer, nut, and other flavors.
- The Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals (11th ed.), Merck, 1989, ISBN 091191028X
- Record in the GESTIS Substance Database of the Institute for Occupational Safety and Health