In short
Decanoic acid, or capric acid, is a fatty acid found in milk fats and coconut oil. JECFA describes its odour as unpleasant and rancid.
What Decanoic Acid smells like
JECFA describes decanoic acid as white crystals with an unpleasant, rancid odour. The Hazardous Substances Data Bank records a rancid, unpleasant odour too.
- Leading note
- Rancid
- Character
- Fatty
What makes Decanoic Acid distinctive
A rancid, fatty acid note, used in traces for its dairy and animalic realism rather than for itself.
How Decanoic Acid is used
Used in traces where a fatty, rancid nuance is wanted, as in dairy-like effects.
Typical role: modifier (used in small amounts to change the character of a blend).
How Decanoic Acid differs from similar materials
- 9-Decenoic Acid
- 9-Decenoic acid, its terminally unsaturated relative, is described as waxy, milky and somewhat fruity.
Each difference compares the published descriptions of the two materials. Smell varies with grade, supplier and dilution; compare them side by side on blotters before substituting one for another.
Formulation considerations
A solid at room temperature; dissolve before use. Unpleasant on its own.
Identity and classification
- Type
- Aroma chemical
- Origin
- Occurs in nature
- Odour family
- Animalic
- Note position
- Heart to base note
- Physical form at room temperature
- Solid
- Also known as
- Capric acid
- CAS number
- 334-48-5
- Molecular formula
- C10H20O2
- Molecular weight
- 172.26 g/mol
- IUPAC name
- decanoic acid
The CAS number, formula and molecular weight are taken from PubChem compound 2969, whose own record lists this CAS number; checked 24 October 2026.
Safety and compliance
Hazard classification of the neat substance, as PubChem summarises it, read 26 October 2026. It has a harmonised EU classification (Regulation (EC) No 1272/2008, Annex VI): H315 causes skin irritation; H319 causes serious eye irritation; H412 harmful to aquatic life with long lasting effects. Companies notifying the ECHA C&L Inventory classify it (2,894 reports): H319 causes serious eye irritation (97.2% of reports); H315 causes skin irritation (95.5% of reports); H412 harmful to aquatic life with long lasting effects (75.3% of reports). 27 of the reports find it does not meet the hazard criteria. Unless it is harmonised, this is the notifiers' own classification, not a binding one.
This page is general information, not a safety assessment or a specification. Confirm identity, composition, IFRA status and allergen content from your supplier's documents for the lot you hold.
Materials it works with
-
gamma-Decalactone
Aroma chemical · Fruity / Gourmand — peach, fruity, creamy
-
Labdanum Absolute
Absolute · Amber / Leather — amber, balsamic, leathery, animalic
-
Indole
Aroma chemical · Animalic / Floral — animalic, indolic, floral, narcotic
Decanoic Acid is also suggested as a partner on the pages for 9-Decenoic Acid.
Used in formulas and accords
Used in 4 published formulas
Decanoic Acid is an ingredient in 4 accords in the Formula & Accord Library.
Further reading
Questions about Decanoic Acid
Is Decanoic Acid natural or synthetic?
The molecule occurs in nature. Commercial Decanoic Acid may be made by synthesis or obtained from natural sources, so check the supplier's specification if the distinction matters to you.
What is the CAS number of Decanoic Acid?
334-48-5. It was checked against PubChem on 24 October 2026.
Which published formulas use Decanoic Acid?
Decanoic Acid is used in 4 published formulas in the RUŌOD Lab Formula & Accord Library, including Brined Olive Accord, Gun Powder Accord and Soy Sauce Accord. Each is listed with a link under "Used in formulas and accords" on this page.
Sources
- PubChem — compound 2969, checked 24 October 2026.
- PubChem — GHS classification (the ECHA C&L Inventory notifications and any harmonised EU entry), read 26 October 2026.
- PubChem — Decanoic Acid (CID 2969): JECFA organoleptic description — odour database.
- PubChem — Decanoic Acid: Hazardous Substances Data Bank (HSDB) odour entry — odour database.
- Olfactory profile: the RUŌOD Lab team's synthesis of the published descriptions above, reviewed 26 October 2026. Evidence: more than one published description. Classification and the short description: revision 1. Descriptions of odour are judgement, not measurement.