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CYCLOPENTADIENE
ICSC: 0857
Peer-Review Status: 26.03.1996 Validated
1,3-Cyclopentadiene
Pentole
Pyropentylene 
CAS #: 542-92-7 RTECS #: GY1000000
UN #: 1993
EINECS #: 208-835-4
    Formula: C5H6
Molecular mass: 66.1

TYPES OF
HAZARD /
EXPOSURE
ACUTE HAZARDS / SYMPTOMS      PREVENTION      FIRST AID / FIRE FIGHTING
FIRE Flammable.  NO open flames, NO sparks and NO smoking.  Use powder, foam, carbon dioxide. 
EXPLOSION Above 25°C explosive vapour/air mixtures may be formed.  Above 25°C use a closed system, ventilation and explosion-proof electrical equipment.  In case of fire: keep drums, etc., cool by spraying with water. 
 
EXPOSURE   PREVENT GENERATION OF MISTS!   
Inhalation Cough. Sore throat.  Use ventilation, local exhaust or breathing protection.  Fresh air, rest. Refer for medical attention. 
Skin   Protective gloves.  Remove contaminated clothes. Rinse and then wash skin with water and soap. 
Eyes Redness. Pain.  Wear safety goggles.  First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention. 
Ingestion   Do not eat, drink, or smoke during work.  Rinse mouth. Refer for medical attention . 

SPILLAGE DISPOSAL
PACKAGING & LABELLING
Personal protection: self-contained breathing apparatus. Collect leaking liquid in sealable containers. Absorb remaining liquid in sand or inert absorbent. Then store and dispose of according to local regulations.  Airtight. 
EC Classification
 
UN Classification
UN Hazard Class: 3; UN Pack Group: III 
GHS Classification
 

EMERGENCY RESPONSE SAFE STORAGE
Transport Emergency Card: TEC (R)-30G35.  Fireproof. Separated from strong oxidants, strong acids and potassium hydroxide. Cooled. Store only if stabilized. 

IMPORTANT DATA
Physical State; Appearance
COLOURLESS LIQUID WITH CHARACTERISTIC ODOUR. 

Physical dangers
The vapour is heavier than air. 

Chemical dangers
The substance can readily form explosive peroxides on contact with air. The substance readily polymerizes to dimer. This generates fire or explosion hazard. The reaction is accelerated by peroxides or trichloroacetic acid. Reacts violently with potassium hydroxide. Reacts violently with strong oxidants and strong acids such as fuming nitric acid and sulfuric acid. This generates fire and explosion hazard. 

Occupational exposure limits
TLV: 75ppm, 203mg/m³ as TWA; (ACGIH 1995). 

Routes of exposure
The substance can be absorbed into the body by inhalation. 

Inhalation risk
A harmful contamination of the air can be reached rather quickly on evaporation of this substance at 20°C. 

Effects of short-term exposure
The substance is irritating to the eyes and respiratory tract. 

Effects of long-term or repeated exposure
 


PHYSICAL PROPERTIES ENVIRONMENTAL DATA
Boiling point: 41.5-42.0°C
Melting point: -85°C
Relative density (water = 1): 0.8
Solubility in water: insoluble
Relative vapour density (air = 1): 2.3
Flash point: 25°C o.c.
Auto-ignition temperature: 640°C  
 

NOTES
Explosive limits are unknown in literature, although the substance is combustible and has a flash point <55°C.
An added stabilizer or inhibitor can influence the toxicological properties of this substance, consult an expert.
Card has been partially updated in November 2008: see Occupational Exposure Limits, Fire fighting. 

ADDITIONAL INFORMATION
 

IPCS
International
Programme on
Chemical Safety
WHO ILO EC Prepared in the context of cooperation between the International Programme on Chemical Safety and the European Commission
© IPCS 2004-2012
LEGAL NOTICE Neither the EC nor the IPCS nor any person acting on behalf of the EC or the IPCS is responsible for the use which might be made of this information.
    See Also:
       Toxicological Abbreviations