In short
Aldehyde C-10, decanal, is an aliphatic aldehyde with a powerful orange-peel and waxy character. It occurs naturally in citrus oils and is used in traces to make citrus accords more natural.
What Aldehyde C-10 (Decanal) smells like
Decanal (aldehyde C-10) is the orange-peel aldehyde: a penetrating, very powerful smell of orange peel with a waxy, fatty texture. Suppliers describe it as sweet, aldehydic, orange, waxy and citrus rind, and as a fatty aldehyde with a penetrating, very powerful orange-peel odour. It changes markedly with dilution: refreshing and citrus-like, with a floral side that develops as it is diluted. It occurs naturally in citrus oils.
- Leading note
- Orange peel
- Clear facets
- Waxy
- Supporting facets
- Fatty
- Faint facets
- Floral, on dilution
- Character
- Waxy, powerful, fresh, peely
What makes Aldehyde C-10 (Decanal) distinctive
It is the peel rather than the juice, and orange rather than lemon: the realistic, slightly waxy smell of a freshly zested orange, rounder than octanal and more orange-specific than nonanal or the C-11 and C-12 aldehydes.
Concentration and dilution
Penetrating and fatty in concentration; on dilution it becomes refreshing and citrus-like and develops a floral character. It is usually weighed from a dilution.
How Aldehyde C-10 (Decanal) is used
Used extensively, at low concentrations, to build citrus nuances — orange, mandarin and grapefruit — and, as Arctander notes, for citrus top notes and floral accords such as neroli, rose, jasmine, violet and acacia. It blends well with linalool and the other aldehydes.
Typical role: modifier (used in small amounts to change the character of a blend); lift (adds diffusion and radiance, especially at the top).
How Aldehyde C-10 (Decanal) differs from similar materials
- Aldehyde C-8 (Octanal)
- Octanal is sharper, greener and more pungent; decanal is the fuller, rounder orange peel.
- Aldehyde C-9 (Nonanal)
- Nonanal shares the waxiness but leans rosy; decanal is orange peel first.
- Aldehyde C-11 Undecylic (Undecanal)
- Undecanal is softer, soapier and more floral; decanal is the more powerful and more specifically orange of the two.
- cis-4-Decenal
- cis-4-Decenal is juicier and more mandarin-like, the pulp rather than the peel; decanal is waxy orange zest.
- trans-2-Decenal
- trans-2-Decenal adds fresh coriander leaf to its orange and is fattier neat; decanal is the cleaner orange peel.
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
Very strong — weigh it from a dilution. Aliphatic aldehydes oxidise to acids over time; keep containers full and cold.
Identity and classification
- Type
- Aroma chemical
- Origin
- Occurs in nature
- Odour family
- Aldehydic / Citrus
- Note position
- Top note
- Physical form at room temperature
- Liquid
- Also known as
- Decanal, Capraldehyde
- CAS number
- 112-31-2
- Molecular formula
- C10H20O
- Molecular weight
- 156.26 g/mol
- IUPAC name
- decanal
The CAS number, formula and molecular weight are taken from PubChem compound 8175, whose own record lists this CAS number; checked 19 October 2026.
Safety and compliance
Hazard classification of the neat substance, as PubChem summarises it, read 26 October 2026. Companies notifying the ECHA C&L Inventory classify it (2,367 reports): H412 harmful to aquatic life with long lasting effects (92.1% of reports); H319 causes serious eye irritation (91.2% of reports); H315 causes skin irritation (21.9% of reports). 66 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
-
Sweet Orange Oil
Essential oil · Citrus / Fruity — citrus, sweet, juicy, orange peel
-
Aldehyde C-8 (Octanal)
Aroma chemical · Aldehydic / Citrus — aldehydic, fatty, citrus, orange
-
Aldehyde C-12 Lauric (Dodecanal)
Aroma chemical · Aldehydic / Floral — aldehydic, waxy, soapy, violet
-
d-Limonene
Aroma chemical · Citrus / Fruity — citrus, orange, fresh, light
-
trans-2-Decenal
Aroma chemical · Aldehydic / Citrus — waxy, orange, coriander leaf, fatty
Aldehyde C-10 (Decanal) is also suggested as a partner on the pages for 1-Nonanol, Aldehyde C-11 Undecylic (Undecanal), cis-4-Decenal, Methyl Nonyl Ketone, Myrac Aldehyde and Octyl Acetate.
Used in formulas and accords
Used in 25 published formulas
Aldehyde C-10 (Decanal) is an ingredient in 11 perfume formulas, 13 accords and 1 base in the Formula & Accord Library.
Community formulas
RUŌOD House Originals
Original compositions by RUŌOD House.
Further reading
Questions about Aldehyde C-10 (Decanal)
Is Aldehyde C-10 (Decanal) natural or synthetic?
The molecule occurs in nature. Commercial Aldehyde C-10 (Decanal) 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 Aldehyde C-10 (Decanal)?
112-31-2. It was checked against PubChem on 19 October 2026.
Which published formulas use Aldehyde C-10 (Decanal)?
Aldehyde C-10 (Decanal) is used in 25 published formulas in the RUŌOD Lab Formula & Accord Library, including Aperol Spritz Accord, Blood Accord and Champagne Accord. Each is listed with a link under "Used in formulas and accords" on this page.
Sources
- PubChem — compound 8175, checked 19 October 2026.
- PubChem — GHS classification (the ECHA C&L Inventory notifications and any harmonised EU entry), read 26 October 2026.
- The Good Scents Company — decanal — odour database.
- Eternis — Aldehyde C-10, via Knowde — manufacturer's description.
- Parchem — decanal — distributor's description.
- S. Arctander, Perfume and Flavor Chemicals (1969), as quoted in a supplier listing — published perfumery reference.
- Olfactory profile: the RUŌOD Lab team's synthesis of the published descriptions above, reviewed 20 October 2026. Evidence: several independent published descriptions, which agree. Classification and the short description: revision 1. Descriptions of odour are judgement, not measurement.