Cyclopentadiene

  • 1,3-Cyclopentadiene
  • Pyropentylene
  • Pentole
Formula
C5H6
Structure
Description
Colorless liquid. Monomeric form has terpene odor in vapor state.
Uses
Manufacture resins, in organic synth as diene in diels-alder reaction producing sesquiterpenes, synthetic alkaloids, camphors.

Registry Numbers and Inventories.
CAS
542-92-7
EC (EINECS/ELINCS)
208-835-4
RTECS
GY1000000
RTECS class
Other
UN (DOT)
2371
Merck
12,2807
Beilstein/Gmelin
471171
Beilstein Reference
4-05-00-00377
Swiss Giftliste 1
G-1466
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Korea ECL
Listed

Properties.
Formula
C5H6
Formula mass
66.1
Melting point, °C
-85
Boiling point, °C
42
Vapor pressure, mmHg
439 (25 C)
Odor Threshold Odor threshold 5.0 mg/m3
Density
0.8021 g/cm3 (20 C)
Solubility in water
Insoluble
Refractive index
1.44632 (20 C)
Partition coefficient, pKow
1.89
Heat of vaporization
27.4 kJ/mol

Hazards and Protection.
Storage
Monomer may largely be prevented from dimerizing by storage at -80C or below.
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 eye protection and protective clothing to prevent skin and eye contact.
Respirators
Wear positive pressure self-contained breathing apparatus (SCBA).
Small spills/leaks
Make no contact with the spilled material. ELIMINATE all ignition sources and ground all equipment. Stop leak if you can do it without risk. A vapor suppressing foam may be used to reduce vapors. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. Use clean non-sparking tools to collect absorbed material.
Stability
No data.
Incompatibilities
Incompatible with nitric acid; oxides of nitrogen; oxygen; sulfuric acid. Contact with strong oxidizing agents may cause explosions. Avoid contact with strong oxidizers, fuming nitric acid, sulfuric acid.
Decomposition
It decomposition violently @ high temp and pressure.

Fire.
Flash Point,°C
-46
Autoignition, °C
640
Upper exp. limit, %
14.6
Lower exp. limit, %
1.7
Fire fighting
Dry chemical, carbon dioxide, foam
Fire potential
Moderate fire hazard, when exposed to heat or flame
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.
Combustion products
Toxic gases and vapors (such as carbon monoxide) may be released in fire involving cyclopentadiene.
Health
-
 
Flammability
2
 

Health.
Exposure limit(s)
TLV (as TWA): 75 ppm; 203 mg/m3 (ACGIH 1995-1996). OSHA PEL: TWA 75 ppm (200 mg/m3) NIOSH REL: TWA 75 ppm (200 mg/m3) NIOSH IDLH: 750 ppm
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
May cause irritation or burns.
   Eyes
Redness, pain.

First aid
 
   Ingestion
Pure petroleum distillates - gastric decontamination is not indicated in the majority of accidental ingestions, since systemic toxicity is unlikely from a pure petroleum distillate. Other hydrocarbons - gastric decontamination may be indicated if a large amount of a toxic hydrocarbon has been ingested (e.G., Suicide attempt) and if spontaneous vomiting has not occurred. Decontamination may also be indicated for ingestions of highly toxic hydrocarbons (e.G., Halogenated hydrocarbons, carbon tetrachloride) and for hydrocarbons which contain very toxic additives (e.G., Heavy metals, pesticides). The decision to decontaminate should be based on the toxicity of the agent, the volume ingested, time of ingestion and patient's clinical status. The potential for rapid cns depression, with seizures and/or respiratory depression, must be considered.
   Inhalation
Move victim to fresh air. Apply artificial respiration if victim is not breathing. Administer oxygen if breathing is difficult.
   Skin
Remove and isolate contaminated clothing and shoes. Wash skin with soap and water. Flush with running water for at least 20 minutes
   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
2371
Response guide
Hazard class
3
Packing Group
I
 
USCG CHRIS Code
CPD
 
IMO Chemical Code
17
IMO Pollution Category
B
IMO Hazard code
P