Propadiene

  • Allene
  • 1,2-Propadiene
  • Prop-1,2-diene
Formula
H2C=C=CH2
Structure
Description
Colorless gas with a sweet odor.
Uses
Chain-transfer reagent in prodn of polybutadiene, fuel gas for metal-working industry (mixt with propyne), monomer for allene polymers (possible use).

Registry Numbers and Inventories.
CAS
463-49-0
EC (EINECS/ELINCS)
207-335-3
S 9 16 33
RTECS
BAO400000
UN (DOT)
2200
Beilstein/Gmelin
1730774
Beilstein Reference
4-01-00-00966
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Korea ECL
Listed

Properties.
Formula
C3H4
Formula mass
40.06
Melting point, °C
-136
Boiling point, °C
-34.5
Vapor pressure, mmHg
5020 (25 C)
Vapor density (air=1)
1.42
Critical temperature
121
Critical pressure
51.8
Density
1.787 g/cm3 (20 C)
Solubility in water
Slightly soluble
Refractive index
1.4168 (20 C)
Partition coefficient, pKow
1.45
Heat of vaporization
21.4 kJ/mol
Heat of combustion
-1946 kJ/mol

Hazards and Protection.
Storage
Store away from incompatible substances. Grounding and bonding is required. Avoid temperatures above room temperature.
Handling
Store and handle in accordance with all current regulations and standards. Subject to storage regulations: U.S. OSHA 29 CFR 1910.106. Keep separated from incompatible substances. Grounding and bonding required.
Protection
Wear appropriate chemical protective clothing.
Respirators
Wear positive pressure self-contained breathing apparatus.
Small spills/leaks
Keep sparks, flames, and other sources of ignition away. Keep material out of water sources and sewers. Attempt to stop leak if without undue personnel hazard. Use water spray to knock-down vapors.
Stability
Unstable. Polymerizes easily.
Incompatibilities
May react vigorously with strong oxidizers Can react exothermically to release gaseous hydrogen Violent explosions have occurred at low temperatures in ammonia synthesis gas units.
Decomposition
Can decompose explosively at 2 atmospheres

Fire.
Flash Point,°C
-96
Upper exp. limit, %
17
Lower exp. limit, %
2.1
Fire fighting
Do not extinguish fire unless flow can be stopped. Use water in flooding quantities as fog. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible.
Fire potential
EXTREMELY FLAMMABLE.
Hazards
May polymerize explosively when heated or involved in a fire. Vapors from liquefied gas are initially heavier than air and spread along ground. Vapors may travel to source of ignition and flash back. Containers may explode when heated. Ruptured cylinders may rocket.
Combustion products
Fire may produce irritating and/or toxic gases.
Health
2
 
Flammability
4
 
 
Reactivity
2
 

Health.
Exposure effects
The toxological properties of this substance have not been fully investigated.
   Ingestion
Avoid contact with air and light.
   Inhalation
May cause irritation.
   Skin
See inhalation.
   Eyes
May cause irritation.

First aid
 
   Ingestion
Seek medical assistance.
   Inhalation
Vapors may cause dizziness or asphyxiation without warning. May be toxic if inhaled at high concentrations.
   Skin
Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite.
   Eyes
Flush with running water for at least 20 minutes.

Transport.
UN number
2200
Response guide
Hazard class
2.1
Std. Transport #
4905722