Isobutylene

  • 2-Methylpropene
  • Isobutene
Formula
CH2=C(CH3)2
Structure
Description
Isobutylene is a colorless gas with a faint petroleum-like odor. For transportation it may be stenched.
Uses
Used to produce trimers & other polymers of isobutylene, to produce antioxidants for foods, to produce antioxidants for packaging, food supplements, & for plastics.

Registry Numbers and Inventories.
CAS
115-11-7
EC (EINECS/ELINCS)
204-066-3
EC Index Number
601-012-00-4
EC Class
Extremely flammable
RTECS
UD0890000
RTECS class
Other
UN (DOT)
1055
Merck
12,5155
Beilstein/Gmelin
773645
Beilstein Reference
4-01-00-00796
Swiss Giftliste 1
G-6787
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
C4H8
Formula mass
56.11
Melting point, °C
-140.3
Boiling point, °C
-6.9
Vapor pressure, mmHg
2308 (20 C)
Vapor density (air=1)
1.9
Critical temperature
145
Critical pressure
39.5
Density
0.5942 g/cm3 (20 C)
Solubility in water
Insoluble
Viscosity
0.0081 cp (30)
Surface tension
12.3 g/s2 (20 C)
Refractive index
1.5072 (20 C)
Partition coefficient, pKow
2.34
Heat of fusion
5.9 kJ/mol
Heat of vaporization
20.6 kJ/mol
Heat of combustion
-2702 kJ/mol

Hazards and Protection.
Storage
Keep in a cool, dry, dark location in a tightly sealed container or cylinder. Keep away from incompatible materials, ignition sources and untrained individuals. Secure and label area. Protect containers/cylinders from physical damage.
Handling
All chemicals should be considered hazardous. Avoid direct physical contact. Use appropriate, approved safety equipment. Untrained individuals should not handle this chemical or its container. Handling should occur in a chemical fume hood.
Protection
Wear appropriate protective gloves, clothing and goggles. Always wear thermal protective clothing when handling refrigerated/cryogenic liquids.
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. Attempt to stop leak if without undue personnel hazard. Use water spray to knock-down vapors.
Stability
Volatile liquid or easily liquefied gas. he substance is able to polymerize with fire or explosion hazard.
Incompatibilities
Incompatible with oxidizers Reacts easily with numerous materials, such as alkyl halides, halogens, concentrated sulfuric acid, hypochlorous acid, aluminum chloride, carbon monoxide and hydrogen with a cobalt catalyst.
Decomposition
When heated to decomposition it emits acrid smoke and fumes.

Fire.
Flash Point,°C
-76
Autoignition, °C
465
Upper exp. limit, %
8.8
Lower exp. limit, %
1.8
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
A very dangerous fire and explosion hazard when exposed to heat or flame.
Hazards
Containers may explode in fire. Vapor is heavier than air and may travel a long distance to a source of ignition and flash back.
Health
2
 
Flammability
4
 
 
Reactivity
1
 

Health.
Poison_Class
4
Exposure effects
Mild central nervous system depression or excitation may occur after ingestion or vapor inhalation. CNS effects can occur secondary to hydrocarbon pneumonitis and hypoxia, or from additives and contaminants (aniline, heavy metals, camphor, or pesticides). Some hydrocarbons are simple asphyxiants (e.G., Methane, ethane, propane gasses) which can produce CNS effects secondary to hypoxia. In a prospective study in Toronto, major congenital malformations were noted in 13 of 125 fetuses of mothers exposed to organic solvents during pregnancy.
   Ingestion
Nausea, vomiting, diarrhea, and abdominal pain may occur following ingestion.
   Inhalation
Coughing, choking, tachypnea, dyspnea, cyanosis, rales, hemoptysis, pulmonary edema, pneumatoceles, lipoid pneumonia, or respiratory arrest may develop following ingestion and aspiration.
   Skin
Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite.
   Eyes
May cause irritation.

First aid
 
   Ingestion
This compound is a gas, therefore inhalation is the first route of exposure.
   Inhalation
IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. If symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop, call a physician and be prepared to transport the victim to a hospital. Provide proper respiratory protection to rescuers entering an unknown atmosphere. Whenever possible, Self-Contained Breathing Apparatus (SCBA) should be used.
   Skin
CAUTION: Exposure of skin to compressed gases may result in freezing of the skin. Treatment for frostbite may be necessary. Remove the victim from the source of contamination. IMMEDIATELY wash affected areas gently with COLD water (and soap, if necessary) while removing and isolating all contaminated clothing. Dry carefully with clean, soft towels. If symptoms such as inflammation or irritation develop, IMMEDIATELY call a physician or go to a hospital for treatment.
   Eyes
First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.

Transport.
UN number
1055
Response guide
Hazard class
2.1
USCG CHRIS Code
IBL
 
Std. Transport #
4905757 4905433 4905434 4905753 4905759