Isoprene

  • 2-Methyl-1,3-butadiene
  • 2-Methylbutadiene
  • Hemiterpene
  • Methyl bivinyl
Formula
CH2=CHC(CH3)=CH2
Structure
Description
A clear colorless liquid with a petroleum-like odor.
Uses
The only chemical reaction of isoprene of commercial importance (other than polymerization) is its conversion to terpenes.

Registry Numbers and Inventories.
CAS
78-79-5
EC (EINECS/ELINCS)
201-143-3
EC Index Number
601-014-00-5
EC Class
Extremely flammable; Dangerous for the Environment
R 12 52/53
S 9 16 29 33 61
RTECS
NT4037000
RTECS class
Tumorigen; Mutagen
UN (DOT)
1218
Merck
13,5220
Beilstein/Gmelin
969158
Beilstein Reference
4-01-00-01001
Swiss Giftliste 1
G-1710
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
C5H8
Formula mass
68.12
Melting point, °C
-146
Boiling point, °C
34
Vapor pressure, mmHg
550 (20 C)
Vapor density (air=1)
2.35
Evaporization number
25 (butyl acetate=1)
Odor Threshold Odor threshold 0.005 ppm
Critical temperature
211.1
Critical pressure
3.7
Density
0.681 g/cm3 (20 C)
Solubility in water
Insoluble
Viscosity
0.225 cP (15 C)
Surface tension
16.9 g/s2 (20 C)
Refractive index
1.4216 (20 C)
Dipole moment
0.15 D
Dielectric constant
2.1 (25 C)
Partition coefficient, pKow
2.42
Thermal expansion
0.0015/K
Heat of fusion
4.833 kJ/mol
Heat of vaporization
25.83 kJ/mol
Heat of combustion
-3185 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. Flammables-area.
B2 D2A
Handling
Wash thoroughly after handling. Use only in a well-ventilated area. 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. Keep away from 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
Wear appropriate protective gloves, clothing and goggles.
Respirators
Wear positive pressure self-contained breathing apparatus (SCBA). Follow the OSHA respirator regulations found in 29 CFR 1910.134 or European Standard EN 149. Always use a NIOSH or European Standard EN 149 approved respirator when necessary.
Small spills/leaks
Keep sparks, flames, and other sources of ignition away. Attempt to stop leak if without undue personnel hazard. Use water spray to knock-down vapors. 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. Apply universal gelling agent to immobilize spill.
Disposal code
1
Stability
Stable. However, it may undergo explosive polymerization if uninhibited.
Incompatibilities
Strong oxidizing agents, bases, alcohols, alkali metals, ammonia, chlorinated solvents, halogens, nitric acid, sulfuric acid, oxygen, ozone, chlorosulfonic acid, oleum, acid chlorides, vinylamine.
Decomposition
Carbon monoxide, irritating and toxic fumes and gases, carbon dioxide. May undergo hazardous polymerization.

Fire.
Flash Point,°C
-48
Autoignition, °C
220
Upper exp. limit, %
9.7
Lower exp. limit, %
1
Fire fighting
Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. Vapors may form an explosive mixture with air. Do not extinguish fire unless flow can be stopped. Use water in flooding quantities as fog. Solid streams of water may spread fire. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible. Use foam, dry chemical, or carbon dioxide.
Fire potential
Extremely flammable liquid.
Hazards
A container may be ruptured on polymerization by heat evolved by a fire or others. Flashback along vapor trail may occur. Containers may explode in fire. Vapor may explode if ignited in an enclosed area.
Combustion products
Toxic vapors are generated when heated May polymerize in containers and explode
Health
1
 
Flammability
4
 
 
Reactivity
2
 

Health.
Carcinogin
I-2B, N-2, CP65
Poison_Class
5
Exposure effects
The toxological properties of this substance have not been fully investigated.
   Ingestion
May cause gastrointestinal irritation with nausea, vomiting and diarrhea.
   Inhalation
May cause respiratory tract irritation. Vapors may cause dizziness or suffocation. Inhalation at high concentrations may cause CNS depression and asphixiation.
   Skin
Moderate irritation
   Eyes
Moderate irritation

First aid
 
   Ingestion
DO NOT INDUCE VOMITING. Volatile chemicals have a high risk of being aspirated into the victim's lungs during vomiting which increases the medical problems. If the victim is conscious and not convulsing, give 1 or 2 glasses of water to dilute the chemical and IMMEDIATELY call a hospital or poison control center. IMMEDIATELY transport the victim to a hospital.
   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
IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water. If symptoms such as redness or irritation develop, IMMEDIATELY call a physician and be prepared to transport the victim 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
1218
Response guide
Hazard class
3
Packing Group
I
 
USCG CHRIS Code
IPR
 
HS Code
2901 24 99
 
Std. Transport #
4907230
 
IMO Chemical Code
17
IMO Pollution Category
C
IMO Hazard code
S/P