2-Methylvaleric acid (CAS 97-61-0) — Musky Base Note Fragrance Ingredient
2-Methylvaleric acid
CAS 97-61-0
What Is 2-Methylvaleric acid?
2-Methylvaleric acid is a synthetic fragrance ingredient that adds cheesy, sweaty, or animalic notes to perfumes. It’s found in trace amounts in some dairy products and fermented foods. This molecule matters because it creates bold, unconventional accords when used skillfully in niche fragrances, adding a raw, human-like quality that contrasts beautifully with florals and woods.
Safety Profile
USE WITH AWARENESSWhat Does 2-Methylvaleric acid Smell Like?
2-Methylvaleric acid unleashes an intense, primal aroma – imagine aged parmesan rind dissolving into warm human skin. The initial burst is aggressively cheesy with sweaty undertones, morphing into a leathery-animalic heart that clings to skin like well-worn suede. In drydown, it reveals a surprisingly soft muskiness when diluted, like the ghost of goat hair on a summer breeze. Used above 0.1%, it dominates; below 0.01%, it adds elusive animalic depth.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
This controversial fragrance uses 2-methylvaleric acid at the threshold of perception to create its infamous ‘bodily fluids’ accord, blending with marine notes for a shocking yet compelling realism.
The acid’s sweaty facets amplify the animalic musk core, creating a scent that evolves from intimate skin warmth to regal fur-lined opulence.
2D Molecular Structure
SMILES: CCCC(C)C(O)=O
Chemistry, Properties & Perfumer Guide
The Chemistry
2-Methylvaleric acid is a branched-chain fatty acid with the molecular formula C6H12O2. It’s synthesized through oxidation of 2-methylpentanol or via Grignard reactions. The molecule’s stereochemistry significantly impacts its odor profile – the (R)-enantiomer is notably more sweaty and intense than the (S)-form. Industrially, it’s produced through hydrocarboxylation of 1-pentene followed by isomerization.
Physical & Chemical Properties
| Boiling Point | 196-198 °C |
|---|---|
| Density | 0.925 g/cm³ |
| Vapor Pressure | 0.3 mmHg at 25°C |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.001-0.01% | Up to 0.1% | Animalic modifier |
| Functional Fragrance | Not used | N/A | Too potent for most applications |
Classic Accords
Tip: Always pre-dilute to 1% in ethanol before incorporating to prevent overwhelming blends.
Alternatives & Comparisons
More cheesey/ranky, less sweaty. Use when seeking sharper dairy notes rather than skin-like musky effects.
Softer, more floral animalic musk with better blending properties for mainstream applications.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
Not restricted under IFRA standards. Self-limiting due to odor potency.
GHS Classification
RIFM Assessment
RIFM evaluation complete – safe for use in current practices at reported levels.
Sustainability
As a synthetic material, 2-methylvaleric acid has minimal environmental impact in production. Its extreme potency means minuscule quantities are used, reducing resource consumption. Some perfumers seek natural analogs from microbial fermentation of dairy byproducts, though these lack consistency.
Explore 2-Methylvaleric acid
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References
- Brenna et al. (2003). Odor detection thresholds of branched fatty acids. Chemical Senses. PMID 12644696
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 97-61-0Physical Properties
| Molecular Weight | 116.16 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 1.8🔬 PubChem |
| Boiling Point | 196 °C🔬 EPA CompTox |
| Vapor Pressure | 0.44 mmHg @ 25°C📊 OPERA |
| Flash Point | 93 °C🔬 EPA CompTox |
| Involatility Index | 0.044💻 Calculated |
| log Kp (skin permeability) | -2.131💻 Calculated |
| SMILES | CCCC(C)C(=O)O🔬 PubChem |
Volatility & Performance
| Fragrance Note | Top💻 Calculated |
| Volatility Class | Slow💻 Calculated |
| Persistence Score | 0.5 / 5💻 Calculated |
Odor & Flavor
| Primary Descriptors | creamypungent• leffingwell |
| “Powerful, pungent-acidulous odor, caramellic-sour. In extreme dilution pleasant oily-acidulous, herbaceous, but of poor tenacity.”📖 Arctander | |
| 2-Methylvaleric acid has a powerful, pungent, acrid odor. At concentrations below 10 ppm, it has an agreeable, sour, oily flavor. At higher concentrations the flavor becomes disagreeable because it is too acidic.📖 Fenaroli | |
Flavor Notes (Arctander)
| “In concentrations lower than 10 ppm the taste is pleasantly sour, oily, "dairy-product-like" with a mild or sweet aftertaste. Higher concentrations show pungency or bite and unpleasantly acid taste. This acid finds some use in flavor compositions, particularly in imitation Cocoa and Chocolate, where”📖 Arctander |
Sensory Thresholds
| Odor Detection Threshold | 10.0191 ppm (n=5)📖 van Gemert |
Regulatory Status
| FEMA Number | FEMA 2754⚖️ FEMA GRAS |
| GRAS Status | Generally Recognized as Safe⚖️ FEMA GRAS |
| IOFI Classification | Nature Identical📖 Fenaroli |
Physical data: PubChem (NIH/NLM), U.S. EPA CompTox Dashboard, EPA OPERA models, RDKit. Odor & flavor: Arctander (Perfume & Flavor Chemicals), Fenaroli's Handbook of Flavor Ingredients, Leffingwell. Thresholds: van Gemert (Compilations of Odour Threshold Values). Regulatory: IFRA Standards 51st, FEMA GRAS. Trade names: Surburg (Common Fragrance & Flavor Materials). All data compiled and cross-referenced for perfumertools.com.
Physicochemical Properties
DTXSID: DTXSID9021633
Physical Properties
| Molecular Weight | 116.16 g/mol🔬 EPA CompTox |
| Density | 0.923 g/cm^3🔬 EPA CTX |
| Boiling Point | 196.25 °C🔬 EPA CTX |
| Melting Point | -85 °C🔬 EPA CTX |
| Flash Point | 91.563 °C🔬 EPA CTX |
| Refractive Index | 1.425 Dimensionless📊 OPERA |
| Molar Volume | 122.578 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 29.556 Log10 unitless🔬 EPA CTX |
| LogD (pH 5.5) | 1.109 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | -0.667 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 4.76 Log10 unitless📊 OPERA |
| Water Solubility | 0.129 mol/L🔬 EPA CTX |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 1.5 mmHg🔬 EPA CTX |
| Viscosity | 2.724 cP📊 OPERA |
| Surface Tension | 28.633 dyn/cm📊 OPERA |
| Thermal Conductivity | 140.815 mW/(m*K)📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 37.3 Ų💻 Computed |
| H-Bond Donors | 1 count💻 Computed |
| H-Bond Acceptors | 1 count💻 Computed |
| Rotatable Bonds | 3 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 31.369 cm^3/mol📊 OPERA |
| Polarizability | 12.436 Å^3📊 OPERA |
Data Sources:
🔬 EPA Experimental data from U.S. EPA CompTox Chemicals Dashboard & CTX APIs. 📊 OPERA Predicted using EPA's OPERA QSAR models. 💻 Computed Calculated from SMILES using RDKit.
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