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
EC Risk Phrase R 34
EC Safety Phrase 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

Odor Threshold Odor threshold 0.0840 mg/m3
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)
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.
WHMIS 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.
NFPA 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 132
Hazard class 8
Packing Group III  
USCG CHRIS Code PNA  
USCG Compatatibility Group 4 Organic acids
HS Code 2915 50 00  
Std. Transport # 4931447  
IMO Chemical Code 17
IMO Pollution Category D
IMO Hazard code S