2,3-Butanedione

  • Dimethyl diketone
  • 2,3-Diketobutane
  • Dimethylglyoxal
  • Diacetyl
  • Butanedione
Formula
CH3COCOCH3
Structure
Description
A clear colorless liquid with a strong chlorine-like odor.
Uses
Carrier of aroma of butter, vinegar, coffee & other foods.

Registry Numbers and Inventories.
CAS
431-03-8
EC (EINECS/ELINCS)
207-069-8
EC Class
highly flammable, harmful, irritant
R 11 20 36/38
S 16 26 36/37/39
RTECS
EK2625000
RTECS class
Tumorigen; Drug; Mutagen; Primary Irritant
UN (DOT)
2346
Merck
13,2985
Beilstein/Gmelin
605398
Beilstein Reference
4-01-00-03644
Swiss Giftliste 1
G-8815
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
C4H6O2
Formula mass
86.09
Melting point, °C
-2
Boiling point, °C
190
Vapor pressure, mmHg
0.01 (-70 C)
Vapor density (air=1)
3
Odor Threshold Odor threshold 8.6 ppb
Density
0.9904 g/cm3
Solubility in water
Miscible
Refractive index
1.39303
Heat of vaporization
38.73 kJ/mol
Heat of combustion
-2072 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/flammables.
Handling
Wash thoroughly after handling. Use only in a well ventilated area. Ground and bond containers when transferring material. Use spark-proof tools and explosion proof equipment. Avoid contact with eyes, skin, and clothing. Empty containers retain product residue, (liquid and/or vapor), and can be dangerous. 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
Follow the OSHA respirator regulations found in 29CFR 1910.134 or European Standard EN 149. Always use a NIOSH or European Standard EN 149 approved respirator when necessary.
Small spills/leaks
Absorb spill with inert material, (e.g., dry sand or earth), then place into a chemical waste container. Remove all sources of ignition. Use a spark-proof tool.
Disposal code
1
Stability
Stable under normal temperatures and pressures.
Incompatibilities
Metals, strong oxidizing agents, strong reducing agents, strong bases.
Decomposition
Carbon monoxide, carbon dioxide.

Fire.
Flash Point,°C
5
Autoignition, °C
365
Upper exp. limit, %
13.0
Lower exp. limit, %
2.4
Fire fighting
Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. Will burn if involved in a fire. Containers may explode in the heat of a fire. Extinguishing media: Use water spray to cool fire-exposed containers. In case of fire use water fog, dry chemical, carbon dioxide or alcohol type foam.
Fire potential
HIGHLY FLAMMABLE.
Hazards
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 may produce irritating, corrosive and/or toxic gases.
Health
2
 
Flammability
3
 
 
Reactivity
0
 

Health.
Poison_Class
4
Exposure effects
Limited studies have generally documented little or no effect of ketones on reproduction in experimental animals. Human data is lacking. 2,5-Hexanedione has an effect on spermatogenesis in male experimental animals.
   Ingestion
Causes gastrointestinal irritation with nausea, vomiting and diarrhea. May be harmful if swallowed.
   Inhalation
May cause respiratory tract irritation.
   Skin
Causes moderate skin irritation. Causes redness and pain.
   Eyes
May cause eye irritation. Causes redness and pain.

First aid
 
   Ingestion
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.
   Inhalation
Remove from exposure to fresh air immediately. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Get medical aid.
   Skin
Get medical aid. Flush skin with plenty of soap and water for at least 15 minutes while removing contaminated clothing and shoes.
   Eyes
Flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid immediately.

Transport.
UN number
2346
Response guide
Hazard class
3
Packing Group
II
 
HS Code
2914 19 90
 
Std. Transport #
4909144