Styrene (CAS 100-42-5) — Sweet N/A Note Fragrance Ingredient
Styrene
CAS 100-42-5
What Is Styrene?
Styrene is a synthetic organic compound primarily used in industrial settings to manufacture plastics, resins, and rubbers. Consumers may encounter it in products like polystyrene foam (Styrofoam) or fiberglass. While not common in perfumery, it’s important to understand due to its widespread industrial use and potential health implications.
Safety Profile
PROFESSIONAL USEWhat Does Styrene Smell Like?
Styrene has a sharp, sweet, and somewhat plastic-like odor, often described as reminiscent of gasoline or rubber. Its scent profile is not typically desirable in perfumery due to its harsh and synthetic character. The odor can be overpowering and lacks the complexity or evolution found in fragrance ingredients.
2D Molecular Structure
SMILES: C=CC1=CC=CC=C1
Chemistry, Properties & Perfumer Guide
The Chemistry
Styrene is an aromatic hydrocarbon with the chemical formula C8H8. It is derived from benzene through the alkylation of ethylene, followed by dehydrogenation. Styrene is primarily polymerized to produce polystyrene, a widely used plastic. Its molecular structure features a vinyl group attached to a benzene ring, contributing to its reactivity and industrial utility.
Physical & Chemical Properties
| Boiling Point | 145 °C |
|---|---|
| Melting Point | -30 °C |
| Flash Point | 31 °C |
| Density | 0.909 g/cm³ |
| Vapor Pressure | 5 mmHg at 20 °C |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Industrial | Not applicable | Not applicable | Primarily used in plastics and resins, not in fragrances |
Classic Accords
Tip: Styrene is not recommended for use in perfumery due to its potential health risks and undesirable odor profile.
Alternatives & Comparisons
A related aromatic hydrocarbon with less pronounced odor and lower volatility, sometimes used in industrial applications.
A safer aromatic compound with a honey-like scent, occasionally used in perfumery.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
Styrene is not regulated by IFRA for perfumery use due to its industrial nature and health risks.
GHS Classification
RIFM Assessment
RIFM does not assess styrene for fragrance use due to its industrial application and toxicity profile.
Sustainability
Styrene production involves significant environmental impact, including petroleum consumption and potential emissions. Its use in single-use plastics raises sustainability concerns. Alternatives like biodegradable polymers are increasingly favored in eco-conscious applications.
Explore Styrene
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References
- National Toxicology Program. (2016). Report on Carcinogens, Fourteenth Edition. NTP Report
- PubChem. (2023). Styrene. PubChem
- EPA. (2023). Styrene Hazard Summary. EPA Hazard Summary
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorPerfumers Notes
Odor Profile
Balsamic, gasoline, pungent.
Regulatory Status
FEMA GRAS #3233 | IOFI: 01.015
Standard Dilution
1% in DPG (ultra-potent — further dilution recommended before assessment)
Typical Usage Levels
FEMA GRAS (#3233) — typical use 0.01-5% in fragrance.
Physicochemical Properties
DTXSID: DTXSID2021284
Physical Properties
| Molecular Weight | 104.152 g/mol🔬 EPA CompTox |
| Density | 0.906 g/cm^3🔬 EPA CTX |
| Boiling Point | 145 °C🔬 EPA CTX |
| Melting Point | -31 °C🔬 EPA CTX |
| Flash Point | 31.625 °C🔬 EPA CTX |
| Refractive Index | 1.558 Dimensionless📊 OPERA |
| Molar Volume | 115.381 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 2.95 Log10 unitless🔬 EPA CTX |
| LogD (pH 5.5) | 3.023 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 3.023 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 3.78 Log10 unitless📊 OPERA |
| Water Solubility | 0.002 mol/L🔬 EPA CTX |
| Henry's Law Constant | 0.003 atm-m3/mole🔬 EPA CTX |
Transport Properties
| Vapor Pressure | 6.4 mmHg🔬 EPA CTX |
| Viscosity | 0.8 cP📊 OPERA |
| Surface Tension | 30.58 dyn/cm📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 0 Ų💻 Computed |
| H-Bond Donors | 0 count💻 Computed |
| H-Bond Acceptors | 0 count💻 Computed |
| Rotatable Bonds | 1 count💻 Computed |
| Aromatic Rings | 1 count💻 Computed |
| Molar Refractivity | 37.177 cm^3/mol📊 OPERA |
| Polarizability | 14.738 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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