2-Oxobutanoic acid

  • a-Ketobutyric acid
  • 2-Ketobutyric acid
  • Propionylformic acid
  • 3-Methylpyruvic acid
  • 2-Oxobutyric acid
Formula
CH3CH2COCOOH
Structure
Description
Colorless paste.

Registry Numbers and Inventories.
CAS
600-18-0
EC (EINECS/ELINCS)
209-986-9
EC Class
irritant
R 36/37/38
Beilstein/Gmelin
1700514
Beilstein Reference
4-03-00-01524
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed

Properties.
Formula
C4H6O3
Formula mass
102.09
Melting point, °C
30 - 32
Boiling point, °C
178
Vapor pressure, mmHg
0.5 (25 C)
Density
1.200 g/cm3 (17C)
Solubility in water
Very soluble
Refractive index
1.3972 (20 C)
pKa/pKb
2.65 (pKa)
Partition coefficient, pKow
-0.53
Heat of vaporization
45.7 kJ/mol

Hazards and Protection.
Storage
Keep away from heat, sparks, and flame. Keep away from sources of ignition. Store in a tightly closed container. Store in a cool, dry, well-ventilated area away from incompatible substances. Refrigerator (approx 4 C).
Handling
Wash thoroughly after handling. Remove contaminated clothing and wash before reuse. Use only in a well ventilated area. Avoid contact with eyes, skin, and clothing. Empty containers retain product residue, (liquid and/or vapor), and can be dangerous. Keep container tightly closed. Avoid contact with heat, sparks and flame. Avoid ingestion and inhalation. 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 respiratory protection program that meets OSHA's 29 CFR 1910.134 and ANSI Z88.2 requirements or European Standard EN 149 must be followed whenever workplace conditions warrant a respirator's use.
Small spills/leaks
Clean up spills immediately, using the appropriate protective equipment. Sweep up or absorb material, then place into a suitable clean, dry, closed container for disposal. Remove all sources of ignition. Use a spark-proof tool. Provide ventilation.
Disposal code
4
Stability
Stable under normal temperatures and pressures.
Incompatibilities
Oxidizing agents, reducing agents, bases.
Decomposition
Carbon monoxide, irritating and toxic fumes and gases, carbon dioxide.

Fire.
Flash Point,°C
65
Fire fighting
Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. During a fire, irritating and highly toxic gases may be generated by thermal decomposition or combustion. Use water spray to keep fire-exposed containers cool. Combustible solid. Containers may explode when heated. Extinguishing media: Use water spray to cool fire-exposed containers. In case of fire use water spray, dry chemical, carbon dioxide, or appropriate foam.
Health
2
 
Flammability
2
 
 
Reactivity
0
 

Health.
Exposure effects
Effects may be delayed.
   Ingestion
Causes gastrointestinal irritation with nausea, vomiting and diarrhea.
   Inhalation
Causes respiratory tract irritation. Aspiration may lead to pulmonary edema. May cause burning sensation, coughing, wheezing, laryngitis, shortness of breath, headache, nausea, and vomiting. Inhalation at high concentrations may cause CNS depression and asphixiation.
   Skin
Causes skin irritation. May cause cyanosis of the extremities.
   Eyes
Causes eye irritation. May cause chemical conjunctivitis.

First aid
 
   Ingestion
Never give anything by mouth to an unconscious person. Get medical aid immediately. Do NOT induce vomiting. If conscious and alert, rinse mouth and drink 2-4 cupfuls of milk or water.
   Inhalation
Get medical aid immediately. Remove from exposure to fresh air immediately. If not breathing, give artificial respiration. If breathing is difficult, give oxygen.
   Skin
Get medical aid immediately. Flush skin with plenty of soap and water for at least 15 minutes while removing contaminated clothing and shoes. Wash clothing before reuse.
   Eyes
Immediately flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid immediately.

Transport.
HS Code
2918 30 00