CAS 79-09-4: Propionic Acid (C3H6O2)
Identity
| CAS Number | 79-09-4 |
| Molecular Formula | C3H6O2 |
| IUPAC Name | propanoic acid |
| Molecular Weight | 74.08 g/mol |
| SMILES | CCC(=O)O |
| Synonyms | propanoic acid, ethanecarboxylic acid, E280 |
2D Structure
Physical Properties
| Density | 0.987 g/mL at 25°C |
| Boiling Point | 141.2°C |
| Melting Point | -20.7°C |
| Flash Point | 54.0°C |
| Vapor Pressure | 0.47 kPa at 20°C |
| Refractive Index | nD = 1.387 |
| Dielectric Constant | ε = 3.4 |
Safety & GHS Classification
GHS05Irritant
- H314: Causes severe skin burns and eye damage
- H335: May cause respiratory irritation
Storage: Store in tightly sealed containers. Pungent rancid odor. Corrosive — handle with PPE. Keep away from oxidizers and bases.
Material Compatibility Matrix
Plastics
| Material | Rating |
|---|---|
| PTFE | Excellent |
| PVC | Good |
| PE | Good |
| PP | Good |
| PEEK | Excellent |
| PVDF | Good |
Rubbers
| Material | Rating |
|---|---|
| Viton | Fair |
| NBR | Severe Effect |
| EPDM | Good |
| Silicone | Fair |
| FKM | Fair |
Metals
| Material | Rating |
|---|---|
| Stainless 316 | Excellent |
| Aluminum | Poor |
| Copper | Poor |
| Brass | Poor |
Applications
- Food preservative (E280 — bread and baked goods)
- Animal feed preservative
- Herbicide intermediate (propionic acid derivatives)
- Cellulose acetate propionate production
- Pharmaceutical intermediate
- Flavor and fragrance agent
- Grain preservative
External References: PubChem