Cinnamic Acid (CAS 621-82-9) — Balsamic Base Note Fragrance Ingredient
Cinnamic Acid
CAS 621-82-9
What Is Cinnamic Acid?
Cinnamic acid is a naturally occurring compound found in cinnamon bark and other plants, giving them their characteristic warm, spicy aroma. It’s commonly encountered in perfumes, flavored foods, and some cosmetic products. This ingredient matters because it serves as a building block for many fragrance molecules and contributes to warm, balsamic notes in perfumery. Its versatility allows perfumers to create everything from spicy oriental scents to sweet gourmand accords.
Safety Profile
USE WITH AWARENESSWhat Does Cinnamic Acid Smell Like?
Cinnamic acid presents a warm, honeyed balsamic character with distinct spicy-cinnamon undertones. Upon first application, it reveals a slightly sharp, phenolic edge that quickly mellows into a rich, resinous heart. The dry-down evolves into a soft vanillic sweetness reminiscent of benzoin, with persistent woody-ambery facets. In blends, it adds depth and warmth, acting as a natural bridge between bright top notes and deep base accords. The aroma profile combines elements of dried fruits, faint floral nuances, and a distinctive cinnamon stick character that becomes creamier over time.
Scent Profile
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used as a key modifier in the vanilla-amber base, contributing to the legendary oriental warmth and helping bridge the citrus top notes to the resinous heart.
Provides authentic cinnamon-spice character in this rich oriental, blending seamlessly with clove and patchouli to create a warm, festive aura.
Contributes to the complex spice accord, adding balsamic depth that complements the myrrh and vanilla in this iconic oriental fragrance.
Works in the amber base to enhance warmth and longevity, pairing with sandalwood to create a sensual, slightly gourmand dry-down.
Provides subtle spicy warmth that balances the sweet floralcy in this powerful masculine fragrance, adding sophistication to the vanilla base.
2D Molecular Structure
SMILES: OC(=O)C=CC1=CC=CC=C1
Chemistry, Properties & Perfumer Guide
The Chemistry
Cinnamic acid is an unsaturated carboxylic acid belonging to the phenylpropanoid class of organic compounds. Naturally occurring as both trans- and cis-isomers, with the trans-form being more common and stable. Industrially produced via Perkin synthesis from benzaldehyde and acetic anhydride, or through microbial fermentation of L-phenylalanine. The molecule’s conjugated π-system contributes to its UV absorption properties and chemical reactivity. As a precursor, it’s hydrogenated to produce hydrocinnamic acid or esterified to create important fragrance materials like cinnamyl acetate and methyl cinnamate.
Physical & Chemical Properties
| Boiling Point | 300 °C |
|---|---|
| Melting Point | 133 °C |
| Density | 1.248 g/cm³ |
| Flash Point | >110 °C |
| Vapor Pressure | 0.000126 mmHg at 25°C |
| Solubility | Slightly soluble in water, soluble in ethanol and ether |
| Appearance | White to pale yellow crystalline powder |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-2% | Up to 3% | Used for warm spicy accents |
| Soaps | 0.1-0.5% | Up to 1% | Adds persistent balsamic character |
| Detergents | 0.05-0.2% | Up to 0.5% | Used sparingly for warmth |
| Candles | 1-3% | Up to 5% | Provides good heat stability |
Classic Accords
Tip: Use in trace amounts with citrus top notes to prevent pH-related discoloration in clear products.
Alternatives & Comparisons
Less spicy but more stable alternative with similar balsamic character, preferred in formulations requiring pH neutrality.
Esterified form with stronger fruity-floral notes and better solubility, used when a sweeter profile is desired.
Alcohol derivative with softer, more floral character and reduced risk of skin sensitization.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. IFRA, REACH, EU Cosmetics Regulation standards update periodically. Consult current IFRA Standards Library before formulating. Not legal or regulatory advice.
IFRA Status
Not currently restricted by IFRA standards. Listed as safe when used within typical fragrance concentrations.
EU Allergen Declaration
Not listed as an EU allergen under Regulation (EC) No 1223/2009.
GHS Classification
RIFM Assessment
RIFM evaluation confirms safe use at current industry levels with no significant risk of phototoxicity or systemic effects.
Sustainability
Primarily synthesized from petrochemical sources, though natural extraction from cinnamon bark or storax resin is possible but less economical. Production via biofermentation using engineered yeast strains shows promise for more sustainable future production. Biodegradability studies show moderate environmental persistence.
Explore Cinnamic Acid
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References
- Bickers et al. (2005). The safety assessment of fragrance materials. Regulatory Toxicology and Pharmacology. PMID 16188365
- Bauer et al. (2008). Common Fragrance and Flavor Materials. Wiley-VCH.
- PubChem Compound Summary for CID 444539 PubChem CID 444539
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Mar 2026.
Report a data errorPhysicochemical Properties
DTXSID: DTXSID40110056
Physical Properties
| Molecular Weight | 148.161 g/mol🔬 EPA CompTox |
| Density | 1.174 g/cm^3📊 OPERA |
| Boiling Point | 281.039 °C📊 OPERA |
| Melting Point | 133.167 °C🔬 EPA CTX |
| Flash Point | 172 °C🔬 EPA CTX |
| Refractive Index | 1.616 Dimensionless📊 OPERA |
| Molar Volume | 125.035 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 2.12 Log10 unitless🔬 EPA CTX |
| LogD (pH 5.5) | 0.895 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | -0.947 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 7.63 Log10 unitless📊 OPERA |
| Water Solubility | 0.004 mol/L🔬 EPA CTX |
| Henry's Law Constant | 0 atm-m3/mole🔬 EPA CTX |
Transport Properties
| Vapor Pressure | 0.002 mmHg📊 OPERA |
| Viscosity | 5.017 cP📊 OPERA |
| Surface Tension | 44.475 dyn/cm📊 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 | 2 count💻 Computed |
| Aromatic Rings | 1 count💻 Computed |
| Molar Refractivity | 43.707 cm^3/mol📊 OPERA |
| Polarizability | 17.327 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.
