In short
Methyl beta ionone (beta-n-methylionone) is a methyl ionone with a powdery orris-violet character and a soft leathery, tobacco depth. Firmenich sells it as Iraldeine Beta.
What Methyl Beta Ionone smells like
Fraterworks describes Iraldeine Beta (methyl ionone beta) as a powdery orris-violet note, clean and slightly woody, with a soft leathery and tobacco depth and a faint creamy-tropical sweetness, bridging floral hearts to woody-leather bases without the candy-violet sweetness of other methyl ionones. IFF describes its grade, Meth Ionone Beta Coeur, as a precious woody, orris-tobacco note with violet nuances, as The Good Scents Company quotes it; that database's own evaluation at 10% lists orris, woody, powdery, floral, violet, tropical, tobacco and creamy.
- Leading note
- Orris
- Clear facets
- Violet
- Supporting facets
- Woody, leathery
- Faint facets
- Tobacco
- Character
- Powdery, dry
What makes Methyl Beta Ionone distinctive
The drier, more leathery member of the methyl ionones.
How Methyl Beta Ionone is used
Used in orris bouquets, violet-leather accords, chypres and woody florals.
Typical role: backbone (used in large proportions as a structural material of an accord); modifier (used in small amounts to change the character of a blend).
How Methyl Beta Ionone differs from similar materials
- Iralia Total
- Iralia Total is the most floral of its maker's methyl ionones, violet and orris; methyl beta ionone is drier, more leathery and tobacco-toned.
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.
Identity and classification
- Type
- Aroma chemical
- Origin
- Occurs in nature
- Odour family
- Powdery / Woody
- Note position
- Heart to base note
- Physical form at room temperature
- Liquid
- Also known as
- beta-Methylionone, Iraldeine Beta
- CAS number
- 127-43-5
- Molecular formula
- C14H22O
- Molecular weight
- 206.32 g/mol
- IUPAC name
- (E)-1-(2,6,6-trimethylcyclohexen-1-yl)pent-1-en-3-one
The CAS number, formula and molecular weight are taken from PubChem compound 5375218, whose own record lists this CAS number; checked 24 October 2026.
Safety and compliance
The IFRA Standards Library lists a Standard covering Methyl Beta Ionone:
- "Methyl ionone, mixed isomers" — type not stated in the library listing, 49th Amendment, published 2020-01
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 (2 reports): H315 causes skin irritation (100% of reports); H317 may cause an allergic skin reaction (100% of reports); H411 toxic to aquatic life with long lasting effects (100% of reports). A skin sensitiser classification concerns handling the neat material and the dose in a finished product; the IFRA Standards, where they apply, set the limits. 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
-
alpha-Isomethyl Ionone
Aroma chemical · Powdery / Floral — powdery, violet, orris, woody
-
beta-Ionone
Aroma chemical · Powdery / Woody — violet, woody, fruity, raspberry
-
Orris Butter (Orris Concrete)
Concrete · Powdery / Woody — powdery, iris, woody, buttery
Used in formulas and accords
Used in 8 published formulas
Methyl Beta Ionone is an ingredient in 6 perfume formulas and 2 accords in the Formula & Accord Library.
Community formulas
RUŌOD House Originals
Original compositions by RUŌOD House.
Further reading
Questions about Methyl Beta Ionone
Is Methyl Beta Ionone natural or synthetic?
The molecule occurs in nature. Commercial Methyl Beta Ionone 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 Methyl Beta Ionone?
127-43-5. It was checked against PubChem on 24 October 2026.
Which published formulas use Methyl Beta Ionone?
Methyl Beta Ionone is used in 8 published formulas in the RUŌOD Lab Formula & Accord Library, including Apricot Dust, Cherry Accord and Freesia Accord. Each is listed with a link under "Used in formulas and accords" on this page.
Is Methyl Beta Ionone covered by an IFRA Standard?
Yes. The IFRA Standards Library lists a Standard covering it: "Methyl ionone, mixed isomers" — type not stated in the library listing, 49th Amendment. The limits depend on the product category; read the Standard itself before formulating.
Sources
- PubChem — compound 5375218, checked 24 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.
- Fraterworks — Iraldeine Beta — distributor's description.
- PubChem — beta-methylionone (CID 5375218) — odour database.
- The Good Scents Company — beta-methyl ionone (with IFF's description) — 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.