Propionic acid

  • Ethanecarboxylic acid
  • Propanoic acid
  • Methylacetic acid
  • Ethylformic acid
  • Carboxyethane
Formula
CH3CH2COOH
Structure
Description
Clear, colorless, oily liquid, pungent, rancid, acrid, irritating, disagreeable odor.
Uses
Used as a mold inhibitor in bread and as an ingredient in perfume. Found in sweat and dairy products. Use as a chemical intermediate for pesticides and pharmaceuticals.

Registry Numbers and Inventories.
CAS
79-09-4
EC (EINECS/ELINCS)
201-176-3
EC Index Number
607-089-00-0
EC Class
Corrosive
S 23 36 45
RTECS
UE5950000
RTECS class
Agricultural Chemical and Pesticide; Mutagen; Primary Irritant
UN (DOT)
1848
Merck
12,8010
Beilstein/Gmelin
506071
Beilstein Reference
4-02-00-00695
EPA OPP
77702
Swiss Giftliste 1
G-2790
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
C3H6O2
Formula mass
74.08
Melting point, °C
-21
Boiling point, °C
141
Vapor pressure, mmHg
3 (25 C)
Vapor density (air=1)
2.56
Saturation Concentration
0.32 to 0.4% at 20 C
Evaporization number
0.24 (butyl acetate=1)
Odor Threshold Odor threshold 0.0840 mg/m3
Critical temperature
328
Critical pressure
44.71
Density
0.99 g/cm3 (20 C)
Solubility in water
Miscible
Viscosity
1.03 cp (25 C)
Surface tension
27.21 g/s2 @ 15 C
Refractive index
1.3848 (20 C)
Dipole moment
1.55 D
Dielectric constant
3.12 (19 C)
pKa/pKb
4.87 (pKa)
Partition coefficient, pKow
0.33
Heat of fusion
10.7 kJ/mol
Heat of vaporization
57.3 kJ/mol
Heat of combustion
-1528.3 kJ/mol

Hazards and Protection.
Storage
Keep away from heat, sparks, and flame. Keep away from sources of ignition. Keep container closed when not in use. Store in a cool, dry, well-ventilated area away from incompatible substances. Flammables-area. Do not store in steel container.
B3 D1B E
Handling
Wash thoroughly after handling. Remove contaminated clothing and wash before reuse. Ground and bond containers when transferring material. Use spark-proof tools and explosion proof equipment. Do not breathe dust, vapor, mist, or gas. Empty containers retain product residue, (liquid and/or vapor), and can be dangerous. Keep container tightly closed. Avoid contact with heat, sparks and flame. Do not get on skin or in eyes. Do not ingest or inhale. Use only in a chemical fume hood. Discard contaminated shoes. Do not pressurize, cut, weld, braze, solder, drill, grind, or expose empty containers to heat, sparks or open flames.
Protection
Eyes: Wear appropriate protective eyeglasses or chemical safety goggles as described by OSHA's eye and face protection regulations in 29 CFR 1910.133 or European Standard EN166. Skin: Wear appropriate protective gloves to prevent skin exposure. Clothing: Wear appropriate protective clothing to prevent skin exposure.
Respirators
A full facepiece respirator with organic vapor cartridge may be worn up to 50 times the exposure limit or the maximum use concentration specified by the appropriate regulatory agency or respirator supplier, whichever is lowest. For emergencies or instances where the exposure levels are not known, use a full-facepiece positive-pressure, air-supplied respirator.
Small spills/leaks
Use water spray to dilute spill to a non-flammable mixture. Large spills may be neutralized with dilute alkaline solutions of soda ash, or lime. Avoid runoff into storm sewers and ditches which lead to waterways. Clean up spills immediately, using the appropriate protective equipment. Cover with sand, dry lime or soda ash and place in a closed container for disposal. Remove all sources of ignition. Use a spark-proof tool. Provide ventilation. A vapor suppressing foam may be used to reduce vapors.
Disposal code
4
Stability
Stable under normal temperatures and pressures.
Incompatibilities
Oxidizing agents, reducing agents, bases, steel, caustics, chromium trioxide, alkalis.
Decomposition
Carbon monoxide, irritating and toxic fumes and gases, carbon dioxide.

Fire.
Flash Point,°C
52
Autoignition, °C
475
Upper exp. limit, %
15
Lower exp. limit, %
3
Fire fighting
Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. Use water spray to keep fire-exposed containers cool. Water may be ineffective. Material is lighter than water and a fire may be spread by the use of water. Containers may explode in the heat of a fire. Extinguishing media: Use water spray to cool fire-exposed containers. Water may be ineffective. Do NOT use straight streams of water. In case of fire, use water spray, dry chemical, carbon dioxide, or alcohol-resistant foam.
Fire potential
Flammable/combustible material.
Hazards
May be ignited by heat, sparks or flames. Vapors may form explosive mixtures with air. Vapors may travel to source of ignition and flash back. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapor explosion hazard indoors, outdoors or in sewers. May polymerize explosively when heated or involved in a fire. Runoff to sewer may create fire or explosion hazard. Containers may explode when heated. Many liquids are lighter than water.
Combustion products
Fire will produce irritating, corrosive and/or toxic gases.
Health
3
 
Flammability
2
 
 
Reactivity
0
 

Health.
Exposure limit(s)
ACGIH Threshold Limit Value (TLV): 10 ppm (TWA)
Poison_Class
3
Exposure effects
Repeated exposure may cause breathing difficulties.
   Ingestion
Material causes irritation and burns to digestive tract. Symptoms may include abdominal pain, vomiting, and diarrhea.
   Inhalation
Causes irritation with unpleasant choking odor. Causes coughing and sneezing, possibly breathing difficulties in large amounts.
   Skin
Causes severe irritation. May have corrosive effects, producing skin burns. Skin absorption may occur with toxic effects.
   Eyes
Corrosive. Causes severe eye irritation and burns. May cause redness, pain, blurred vision, and eye damage.

First aid
 
   Ingestion
Do NOT induce vomiting. If victim is conscious and alert, give 2-4 cupfuls of milk or water. Never give anything by mouth to an unconscious person. Get medical aid immediately.
   Inhalation
Get medical aid immediately. Remove from exposure to fresh air immediately. If breathing is difficult, give oxygen. DO NOT use mouth-to-mouth respiration. If breathing has ceased apply artificial respiration using oxygen and a suitable mechanical device such as a bag and a mask.
   Skin
Get medical aid immediately. Immediately flush skin with plenty of soap and water for at least 15 minutes while removing contaminated clothing and shoes. Wash clothing before reuse. Destroy contaminated shoes.
   Eyes
Get medical aid immediately. Do NOT allow victim to rub or keep eyes closed. Extensive irrigation is required (at least 30 minutes).

Transport.
UN number
1848
Response guide
Hazard class
8
Packing Group
III
 
USCG CHRIS Code
PNA
 
HS Code
2915 50 00
 
Std. Transport #
4931447
 
IMO Chemical Code
17
IMO Pollution Category
D
IMO Hazard code
S