Propionic acid CAS#79-09-4
1. Versatile Reactivity:
Propionic acid can participate in ester production, neutralization, and hydrogenation, offering flexibility for various industrial applications.
2. Solubility and Compatibility:
It mixes completely with water and dissolves well in organic solvents like ethanol and chloroform, broadening its use in different formulations.
3. Safe Handling:
With relatively low toxicity (LD50 in rats: 4.29 g/kg) and stable properties, it remains safe for industrial use under controlled conditions, despite its flammability.
4. Distinctive Odor:
Its strong, acidic smell (similar to vinegar or cheese) helps identify its presence in different applications.
Propionic acid, alternatively called propanoic acid, is a three-carbon saturated fatty acid and a representative volatile short-chain carboxylic acid. Molecular formula: CH₃CH₂COOH. Molecular mass: 74.08. A colorless, transparent, oily fluid with a characteristic pungent smell. Freezing point: -20.8°C, boiling point: 140.99°C (41.65°C at 1330Pa), specific gravity: 0.9930, refractive index: 1.3869.
Acid dissociation constant (Ka) = 1.34 × 10⁻⁵. Completely mixable with water. Dissolves readily in ethanol, chloroform and diethyl ether. Reactive in nature, exhibiting acidity, and able to participate in various chemical reactions including neutralization, ester production and hydrogenation.
Melting point | −24-−23 °C(lit.) |
Boiling point | 141 °C(lit.) |
density | 0.993 g/mL at 25 °C(lit.) |
vapor density | 2.55 (vs air) |
vapor pressure | 2.4 mm Hg ( 20 °C) |
refractive index | n20/D 1.386(lit.) |
FEMA | 2924 | PROPIONIC ACID |
Fp | 125 °F |
storage temp. | Store below +30°C. |
solubility | organic solvents: soluble(lit.) |
pka | 4.86(at 25℃) |
form | Liquid |
Specific Gravity | 0.996 (20/4℃) |
color | ≤10, APHA: |
PH | 3.96(1 mM solution);3.44(10 mM solution);2.94(100 mM solution); |
Odor | at 0.10 % in propylene glycol. pungent acidic cheesy vinegar |
Odor Type | acidic |
biological source | synthetic |
Odor Threshold | 0.0057ppm |
explosive limit | 2.1-12%(V) |
Water Solubility | 37 g/100 mL |
JECFA Number | 84 |
Merck | 14,7825 |
BRN | 506071 |
Exposure limits | TLV-TWA 10 ppm (～30 mg/m3) (ACGIH). |
Dielectric constant | 3.2（Ambient） |
Stability: | Stable. Incompatible with strong oxidizing agents. Flammable. |
InChIKey | XBDQKXXYIPTUBI-UHFFFAOYSA-N |
LogP | 0.33 at 25℃ |
Surface tension | 24.07mN/m at 298.15K |
CAS DataBase Reference | 79-09-4(CAS DataBase Reference) |
NIST Chemistry Reference | Propanoic acid(79-09-4) |
EPA Substance Registry System | Propionic acid (79-09-4) |
Safety Information
Hazard Codes | C |
Risk Statements | 36/37/38-34-10 |
Safety Statements | 26-36-45-23 |
RIDADR | UN 3463 8/PG 2 |
OEB | A |
OEL | TWA: 10 ppm (30 mg/m3), STEL: 15 ppm (45 mg/m3) |
WGK Germany | 1 |
RTECS | UE5950000 |
Autoignition Temperature | 955 °F |
TSCA | Yes |
HazardClass | 8 |
PackingGroup | II |
HS Code | 29155010 |
Hazardous Substances Data | 79-09-4(Hazardous Substances Data) |
Toxicity | LD50 orally in rats: 4.29 g/kg (Smyth) |
