Propionic Acid
Propionic acid, also referred to as propanoic acid, is a saturated monocarboxylic acid containing three carbon atoms and is classified as a typical volatile lower fatty acid. Its chemical formula is CH₃CH₂COOH, with a molecular weight of 74.08.
It appears as a colorless, transparent oily liquid with a strong pungent and rancid odor. The compound has a melting point of -20.8°C, a boiling point of 140°C, a boiling point of 41.65°C at 1330 Pa, a relative density of 0.9930, and a refractive index of 1.3869. Its acid dissociation constant is Ka = 1.34 × 10⁻⁵.
Propionic acid is completely miscible with water and is also soluble in alcohols, chloroform, and ethers. It exhibits typical acidic chemical properties and can participate in reactions such as salt formation, esterification, and reduction.
Properties
| 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) |
| FEMA | 2924 | PROPIONIC ACID |
| refractive index | n20/D 1.386(lit.) |
| 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 |
| explosive limit | 2.1-12%(V) |
| Odor Threshold | 0.0057ppm |
| Water Solubility | 37 g/100 mL |
| JECFA Number | 84 |
| Merck | 147825 |
| 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℃ |
| 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) |
Product Application
Propionic acid is widely used in the production of propionates, which serve as mold inhibitors and preservatives for grains and wood chips. It is also utilized in the manufacture of fruit flavors, perfume bases, and as an esterification agent in chemical synthesis.
Propionic acid is the primary acid source for propionate compounds. Due to the strong odor and corrosive nature of liquid propionic acid, it is commonly used in the form of sodium, calcium, and potassium salts as preservatives. In food applications, these salts release free propionic acid within the product’s pH range, where it functions mainly as an effective mold inhibitor.
Factory Tour
Package And Shipping
