Diketene

  • Diketene, inhibited
  • Acetyl ketene
  • 4-Methylene-2-oxetanone
  • But-3-en-3-olide
  • 2-Oxetanone, 4-methylene
Formula
C4H4O2
Structure
Description
A colorless liquid with a disagreeable odor.
Uses
Chemical intermediate for acetoacetic esters & acetoacetanilides, n,n-dialkylacetoacetamides, dyes, pharmaceuticals, for pigments & toners, food preservatives, insecticides, dicrotophos, & the fungicide, dehydroacetic acid.

Registry Numbers and Inventories.
CAS
674-82-8
EC (EINECS/ELINCS)
211-617-1
EC Index Number
606-017-00-5
EC Class
Flammable; Harmful
RTECS
RQ8225000
RTECS class
Primary Irritant
UN (DOT)
2521
Beilstein/Gmelin
104541
Beilstein Reference
5-17-09-00115
Swiss Giftliste 1
G-8268
Canada DSL/NDSL
NDSL
US TSCA
Listed
Austrailia AICS
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
C4H4O2
Formula mass
84.08
Melting point, °C
-7
Boiling point, °C
126 - 128
Vapor pressure, mmHg
11 (25 C)
Vapor density (air=1)
2.9
Density
1.0897 g/cm3 (20 C)
Solubility in water
Soluble
Viscosity
0.88 cp
Surface tension
31.82 g/s2 (20 C)
Refractive index
1.438 (4 C)
Partition coefficient, pKow
0.27
Heat of vaporization
36.8 kJ/ol
Heat of combustion
-1913 kJ/mol

Hazards and Protection.
Storage
Store at 32F (0C) in a standard flammable liquids storage warehouse, room, or cabinet. Special vented containers may be required. Separate from oxidizing materials, acids, and alkalies. Protect against damage. Keep in containers made of fluorosilicone glass or stainless steel in a standard combustible material store at or near 0C.
Handling
Wash thoroughly after handling. Remove contaminated clothing and wash before reuse. Use with adequate ventilation. Ground and bond containers when transferring material. 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
Protective gloves and clothing. Safety goggles or eye protection in combination with breathing protection.
Respirators
Wear positive pressure self-contained breathing apparatus (SCBA).
Small spills/leaks
Keep sparks, flames, and other sources of ignition away. Keep material out of water sources and sewers. Build dikes to contain flow as necessary. Attempt to stop leak if without undue personnel hazard. Use water spray to knock-down vapors. Disperse vapors using fans or blowers. Land spill: Dig a pit, pond, lagoon, holding area to contain liquid or solid material. Dike surface flow using soil, sand bags, foamed polyurethane, or foamed concrete. Absorb bulk liquid with fly ash, cement powder, or commercial sorbents. Water spill: Use natural barriers or oil spill control booms to limit spill travel. Remove trapped material with suction hoses.
Stability
Readily polymerizes on standing.
Incompatibilities
Reacts with water to form acetone and carbon dioxide. Presence of mineral, or lewis acids, or bases including amines, will catalyze violent polymerization.
Decomposition
Diketene residues in a tank trailer awaiting incineration decomposed violently on standing, blew off the dome cover and ignited. Begins to react and decompose exothermically at 208 F (98 C) or lower if contaminated.

Fire.
Flash Point,°C
34
Autoignition, °C
310
Upper exp. limit, %
16.8
Lower exp. limit, %
2.5
Fire fighting
Do not extinguish fire unless flow can be stopped. Use water in flooding quantities as fog. Solid streams of water may be ineffective. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible. Use alcohol foam, dry chemical or carbon dioxide. Keep run-off water out of sewers and water sources.
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 and poison 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
3
 
 
Reactivity
2
 

Health.
Poison_Class
1
Exposure effects
Agitation and syncope, both attributed to panic, have been reported.
   Ingestion
A metallic taste with a burning sensation of the tongue is common. Nausea is common; vomiting occurs occasionally. Epigastric discomfort and burping may occur if tear gas is swallowed.
   Inhalation
Cough, rhinorrhea, sneezing, chest tightness, and laryngospasm may occur shortly following exposure due to the irritant effects.
   Skin
Irritation may occur to all body surfaces where significant exposure has occurred. Painful contact dermatitis may persist for several hours following exposure to mace containing capsaicin. Bullous dermatitis may develop 12 to three days after exposure to tear gas containing o-chlorobenzylidene malononitrile (cs). Erythema, vesicle eruptions, and denuded areas with weeping tender erythematous base may develop one day after exposure to mace containing 1-chloroacetophenone (cn).
   Eyes
Redness, pain, blurred vision.

First aid
 
   Ingestion
Seek medical assistance.
   Inhalation
Move patient to fresh air. Monitor for respiratory distress. If cough or difficulty breathing develops, evaluate for respiratory tract irritation, bronchitis, or pneumonitis. Administer oxygen and assist ventilation as required. Treat bronchospasm with beta2 agonist and corticosteroid aerosols.
   Skin
Remove contaminated clothing and wash exposed area thoroughly with soap and water. A physician should examine the area if irritation or pain persists. Remove all contaminated clothing while avoiding self-contamination. Meticulously wash all exposed areas with copious amounts of soap and water. The patient's clothing may contain residual particles from the exposure and clothing should be removed and stored in a sealed polythene bag to prevent degassing. If clothing is to be washed, cold water should be used because hot wat will cause residual o-chlorobenzylidene malononitrile (cs) gas to vaporize.
   Eyes
Irrigate exposed eyes with copious amounts of tepid water for at least 15 minutes. If irritation, pain, swelling, lacrimation, or photophobia persist, the patient should be seen in a health care facility.

Transport.
UN number
2521
Response guide
Hazard class
6.1
PRTC
T
Packing Group
I
 
Std. Transport #
4921254 4912433