In short
3-Methyl-2,4-nonanedione is a dione flavour molecule with a dry, hay-like character that Bedoukian describes as reminiscent of green and black tea. It is used in traces, from dilution.
What 3-Methyl-2,4-nonanedione smells like
Bedoukian describes 3-methyl-2,4-nonanedione as a sweet, hay character reminiscent of green and black tea, with cream notes at lower levels, and says its dry, hay character contributes to green and black tea flavours. The Good Scents Company records it at 10% in dipropylene glycol as fruity, straw, caramel and burnt, and Treatt's description as straw-like and fruity.
- Leading note
- Hay
- Clear facets
- Tea
- Supporting facets
- Straw, fruity
- Faint facets
- Caramel, creamy
- Character
- Dry, intense
What makes 3-Methyl-2,4-nonanedione distinctive
A dry hay-and-tea dione used in traces: it reads as dried leaf and straw rather than as fresh green.
Concentration and dilution
Sources describe it at 10% and at flavour levels; at low levels the cream note comes forward.
Where the descriptions disagree: Reseller listings for the product called Green Tea Ketone give differing CAS numbers; the CAS here is PubChem's and Bedoukian's for the molecule itself.
How 3-Methyl-2,4-nonanedione is used
Used in traces as a booster in tea, hay and dried-herb effects; in flavours it supports green and black tea, caramel and dairy notes.
Typical role: modifier (used in small amounts to change the character of a blend).
Formulation considerations
Very strong: Bedoukian suggests 0.02–2 ppm in flavours, and it is usually handled at 1% or weaker. Small hobby sellers sell a product called Green Tea Ketone at 1% and give this molecule as its identity; that identity is reported by resellers, not by a maker, so formulas naming Green Tea Ketone are adapted to this record rather than read as it.
Identity and classification
- Type
- Aroma chemical
- Origin
- Occurs in nature
- Odour family
- Green / Gourmand
- Note position
- Heart note
- Physical form at room temperature
- Liquid
- Also known as
- 3-Methylnonane-2,4-dione, Methyl nonane dione
- CAS number
- 113486-29-6
- Molecular formula
- C10H18O2
- Molecular weight
- 170.25 g/mol
- IUPAC name
- 3-methylnonane-2,4-dione
The CAS number, formula and molecular weight are taken from PubChem compound 529481, whose own record lists this CAS number; checked 4 November 2026.
Safety and compliance
Hazard classification of the neat substance, as PubChem summarises it, read 4 November 2026. Companies notifying the ECHA C&L Inventory report it as not meeting the GHS hazard criteria (98 of 99 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
-
Mate Absolute
Absolute · Green / Aromatic — tea, hay, herbal, tobacco
-
Hay Absolute
Absolute · Green / Gourmand — hay, coumarinic, tobacco, herbal
-
Theaspirane
Aroma chemical · Woody / Aromatic — tea, woody, camphor, minty
Used in formulas and accords
Not currently used in any published formula.
The Formula & Accord Library lists 3-Methyl-2,4-nonanedione here as soon as a published formula, accord or base uses it.
Further reading
Questions about 3-Methyl-2,4-nonanedione
Is 3-Methyl-2,4-nonanedione natural or synthetic?
The molecule occurs in nature. Commercial 3-Methyl-2,4-nonanedione 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 3-Methyl-2,4-nonanedione?
113486-29-6. It was checked against PubChem on 4 November 2026.
Sources
- PubChem — compound 529481, checked 4 November 2026.
- PubChem — GHS classification (the ECHA C&L Inventory notifications and any harmonised EU entry), read 4 November 2026.
- Bedoukian Research — 3-Methyl-2,4-nonanedione (BRI #841) specification — manufacturer's description.
- The Good Scents Company — 3-methyl-2,4-nonanedione — odour database.
- PubChem — 3-Methylnonane-2,4-dione (CID 529481) — odour database.
- Harrison Joseph — Green Tea Ketone (sold at 1% in DPG) — distributor's description.
- Olfactory profile: the RUŌOD Lab team's synthesis of the published descriptions above, reviewed 5 November 2026. Evidence: few published descriptions; treat the detail with caution. Classification and the short description: revision 1. Descriptions of odour are judgement, not measurement.