In short
Amber Core is a trade name for 1-(2-tert-butylcyclohexyloxy)butan-2-ol, a woody-amber material. It gives a dry, warm amber note that blends easily.
What Amber Core smells like
Amber Core (Kao) offers a soft, delicate woody-amber note with a refined natural richness, in Kao's own description. A chemical reference lists amber, woody, soft and sweet; a supplier delicate wood and amber; resellers find it much softer than typical amber materials, very soft and airy, and similar to Cedramber in strength. One more promotional page describes sweet, intense ambergris with spicy-woody and marine facets.
- Leading note
- Soft woody amber
- Supporting facets
- Sweet, airy
- Faint facets
- Marine
- Character
- Soft, delicate, airy
What makes Amber Core distinctive
The gentlest woody amber: soft, airy and refined, without the dry ambers' sharpness.
Where the descriptions disagree: Most describe it as soft and delicate; one promotional page calls it intense.
How Amber Core is used
Used as a soft woody-amber body in a wide range of compositions; Kao recommends it in large proportions, though IFRA restricts it.
Typical role: fixative (slow to evaporate; helps a blend last and holds lighter notes); blender (smooths the joins between other materials).
How Amber Core differs from similar materials
- Cedramber
- A reseller finds it similar to Cedramber in strength; Amber Core is softer and more delicate, Cedramber drier, with cedar. (compared directly by a cited source)
- Boisambrene Forte
- Boisambrene Forte is a more diffusive, noble woody amber; Amber Core is softer and more delicate.
An asterisk marks a difference that a cited source states directly. The others compare the published descriptions of each material. Smell varies with grade, supplier and dilution; compare them side by side on blotters before substituting one for another.
Identity and classification
- Type
- Aroma chemical
- Origin
- Synthetic
- Odour family
- Amber / Woody
- Note position
- Base note
- Physical form at room temperature
- Liquid
- Also known as
- 1-(2-tert-Butylcyclohexyloxy)butan-2-ol
- CAS number
- 139504-68-0
- Molecular formula
- C14H28O2
- Molecular weight
- 228.37 g/mol
- IUPAC name
- 1-(2-tert-butylcyclohexyl)oxybutan-2-ol
The CAS number, formula and molecular weight are taken from PubChem compound 164422, whose own record lists this CAS number; checked 19 October 2026.
Safety and compliance
The IFRA Standards Library lists a Standard covering Amber Core:
- "1-(2-tert.-Butyl cyclohexyloxy)-2-butanol" — Restriction, 51st Amendment, published 2023-06
Limits differ by product category and are set out in the Standard itself; this page does not reproduce them. The list above reflects the library as read on 19 October 2026.
Hazard classification of the neat substance, as PubChem summarises it, read 26 October 2026. Companies notifying the ECHA C&L Inventory classify it (1,651 reports): H411 toxic to aquatic life with long lasting effects (100% of reports); H319 causes serious eye irritation (80.7% of reports). 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
-
Ambroxan
Aroma chemical · Amber / Woody — amber, ambergris, woody, mineral
-
Iso E Super
Aroma chemical · Woody / Amber — woody, velvety, amber, cedar
-
Cedramber
Aroma chemical · Woody / Amber — woody, amber, dry, cedar
-
Vanillin
Aroma chemical · Gourmand / Amber — vanilla, sweet, creamy
Used in formulas and accords
Used in 13 published formulas
Amber Core is an ingredient in 13 perfume formulas in the Formula & Accord Library.
RUŌOD House Originals
Original compositions by RUŌOD House.
Further reading
Questions about Amber Core
Is Amber Core natural or synthetic?
Amber Core is synthetic — it is made by chemical synthesis.
What is the CAS number of Amber Core?
139504-68-0. It was checked against PubChem on 19 October 2026.
Which published formulas use Amber Core?
Amber Core is used in 13 published formulas in the RUŌOD Lab Formula & Accord Library, including Beeswax Throne, Black Saddle and Cherry Lacquer. Each is listed with a link under "Used in formulas and accords" on this page.
Is Amber Core covered by an IFRA Standard?
Yes. The IFRA Standards Library lists a Standard covering it: "1-(2-tert.-Butyl cyclohexyloxy)-2-butanol" — Restriction, 51st Amendment. The limits depend on the product category; read the Standard itself before formulating.
Sources
- PubChem — compound 164422, checked 19 October 2026.
- PubChem — GHS classification (the ECHA C&L Inventory notifications and any harmonised EU entry), read 26 October 2026.
- IFRA — Standards Library, read 19 October 2026.
- Kao — Amber Core — manufacturer's description.
- Fraterworks — Amber Core — distributor's description.
- The Fragrance Foundry — Ambercore (Kao) — distributor's description.
- Olfactory profile: the RUŌOD Lab team's synthesis of the published descriptions above, reviewed 21 October 2026. Evidence: more than one published description. Classification and the short description: revision 1. Descriptions of odour are judgement, not measurement.