Levulinic acid (CAS 123-76-2) — Sweet Base Note Fragrance Ingredient

Sweet · Balsamic

Levulinic acid

CAS 123-76-2

Origin
synthetic
Note
Base
IFRA
Generally safe
Data as of: Apr 2026

What Is Levulinic acid?

Levulinic acid is a synthetic organic acid occasionally used in fragrances as a fixative or modifier. You might encounter it in niche perfumes where it adds a subtle, caramel-like depth. While not a star ingredient, it plays a supporting role in creating warm, gourmand accords. This molecule matters because it’s a bio-based platform chemical, offering sustainable alternatives to petrochemical-derived ingredients in modern perfumery.

Safety Profile

GENERALLY SAFE
Generally safeUse with awarenessProfessional use
Low toxicity profile
Mild irritant at high concentrations
CAS
123-76-2
Formula
Mixture
MW
Variable
Odor Family
Sweet · Balsamic
Layer 1 · Enthusiast

What Does Levulinic acid Smell Like?

Levulinic acid presents a subtle, warm character reminiscent of caramelized sugar with a faintly buttery undertone. Its odor is relatively mild compared to other acids, acting more as a background modifier than a primary scent. In blends, it adds a soft sweetness that evolves into a gentle, powdery dry-down. The effect is like distant baker’s notes – not overtly gourmand, but providing a comforting warmth when combined with vanillic or balsamic materials.

Scent Profile
Layer 2

2D Molecular Structure

4-Oxopentanoic acid

SMILES: CC(=O)CCC(O)=O

Chemistry, Properties & Perfumer Guide

The Chemistry

Levulinic acid (C5H8O3) is a keto acid derived from cellulose biomass through acid hydrolysis. Industrially produced from sugars via dehydration, it serves as a platform chemical for sustainable fragrance ingredients. The molecule contains both carboxylic acid and ketone functional groups, allowing versatile chemical modifications. Its production from agricultural waste makes it increasingly important in green chemistry applications for perfumery.

Physical & Chemical Properties

Boiling Point245-246 °C
Melting Point33-35 °C
Density1.14 g/cm³

Perfumer Guide

Note Position
Base
Volatility
Low (hours+)
Blending
Moderate
ApplicationTypical %RangeNotes
Fine Fragrance0.1-0.5%Up to 1%Background modifier
Functional Fragrance0.05-0.2%Up to 0.5%Fixative properties

Classic Accords

Tip: Use sparingly to avoid overpowering other notes – works best as a subtle sweetener in oriental compositions.

Alternatives & Comparisons

1
Acetylpropionic acid CAS 123-76-2

Same compound under alternative name, used interchangeably in formulations.

2
4-Oxopentanoic acid CAS 123-76-2

IUPAC name for identical chemical structure in technical specifications.

Layer 3

Safety, Regulatory & Sustainability

⚠ Regulatory Disclaimer

General reference only. Consult current IFRA Standards Library before formulating.

IFRA Status

No IFRA restrictions currently apply to levulinic acid (as of Amendment 51).

GHS Classification

H315 Skin irritation

RIFM Assessment

RIFM has reviewed levulinic acid and found it safe for current fragrance use levels.

Sustainability

Levulinic acid represents a sustainable advancement as it’s produced from biomass like agricultural waste. Its bio-based origin reduces reliance on petrochemicals, though energy-intensive production processes still require optimization. The molecule’s potential for creating other green fragrance ingredients makes it strategically important for eco-conscious perfumery.

Explore Levulinic acid

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References

  1. Bozell et al. (2000). Levulinic acid production. Green Chemistry. DOI Link
  2. PubChem Compound Summary for Levulinic acid PubChem CID: 11579

Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.

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Perfumer’s Notes

FEMA #: 2627  |  IOFI #: Nature Identical

Levulinic acid has a tart, whiskey taste.

Odor: [‘caramellic’]

MW: 116.11

LogP: -0.5

Ingredient Data Sheet

CAS 123-76-2

Physical Properties

Molecular Weight116.11 g/mol🔬 PubChem
LogP (Octanol-Water)-0.5🔬 PubChem
Boiling Point245.5 °C🔬 EPA CompTox
log Kp (skin permeability)-3.763💻 Calculated
SMILESCC(=O)CCC(=O)O🔬 PubChem

Volatility & Performance

Fragrance NoteHeart💻 Calculated

Odor & Flavor

Primary Descriptorscaramel• leffingwell
Functional Groupsketone💻 RDKit
“Mild caramellic odor, or almost odorless (when pure). Decomposition causes acid odor and pungency.”📖 Arctander
Levulinic acid has a tart, whiskey taste.📖 Fenaroli

Flavor Notes (Arctander)

“Pleasant, acid taste in proper dilution. The acidulous taste is accompanied by a caramellic flavor giving the impression of sweetness with the acidity. It finds extensive use in flavors, partly as a component of various Berry-type flavor compositions, Butter, Maple and Nut imitations, Caramel and va”📖 Arctander

Regulatory Status

FEMA NumberFEMA 2627⚖️ FEMA GRAS
GRAS StatusGenerally Recognized as Safe⚖️ FEMA GRAS
IOFI ClassificationNature Identical📖 Fenaroli
Data Sources & Attribution
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: DTXSID8021648

Physical Properties

Molecular Weight 116.116 g/mol🔬 EPA CompTox
Density 1.137 g/cm^3🔬 EPA CTX
Boiling Point 247.113 °C🔬 EPA CTX
Melting Point 31.31 °C🔬 EPA CTX
Flash Point 132.65 °C🔬 EPA CTX
Refractive Index 1.435 Dimensionless📊 OPERA
Molar Volume 102.815 cm^3/mol📊 OPERA

Partition & Solubility

LogP (Octanol-Water) -0.491 Log10 unitless🔬 EPA CTX
LogD (pH 5.5) -1.179 Log10 unitless📊 OPERA
LogD (pH 7.4) -2.981 Log10 unitless📊 OPERA
LogKoa (Octanol-Air) 4.92 Log10 unitless📊 OPERA
Water Solubility 1.163 mol/L📊 OPERA
Henry's Law Constant 0 atm-m3/mole📊 OPERA

Transport Properties

Vapor Pressure 0.003 mmHg🔬 EPA CTX
Viscosity 3.194 cP📊 OPERA
Surface Tension 34.742 dyn/cm📊 OPERA
Thermal Conductivity 156.058 mW/(m*K)📊 OPERA

Molecular Descriptors

Topological Polar Surface Area 54.37 Ų💻 Computed
H-Bond Donors 1 count💻 Computed
H-Bond Acceptors 2 count💻 Computed
Rotatable Bonds 3 count💻 Computed
Aromatic Rings 0 count💻 Computed
Molar Refractivity 26.807 cm^3/mol📊 OPERA
Polarizability 10.627 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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