International Chemical Safety Cards CYCLOPENTADIENE ICSC: 0857 1,3-Cyclopentadiene Pentole Pyropentylene C5H6 Molecular mass: 66.1 ICSC #    0857 CAS #     542-92-7 RTECS # GY1000000 UN #        1993 March 26, 1996 Peer reviewed TYPES OF HAZARD/ EXPOSURE ACUTE HAZARDS/ SYMPTOMS PREVENTION FIRST AID/ FIRE FIGHTING FIRE Flammable. NO open flames, NO sparks, and NO smoking. Powder, AFFF, 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. 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. Safety goggles. First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then take to a doctor.  •INGESTION Do not eat, drink, or smoke during work. Rinse mouth. Refer for medical attention. SPILLAGE DISPOSAL STORAGE PACKAGING & LABELLING Collect leaking and spilled liquid in sealable containers as far as possible. Absorb remaining liquid in sand or inert absorbent and remove to safe place. (Extra personal protection: self-contained breathing apparatus). Fireproof. Separated from strong oxidants, strong acids, potassium hydroxide. Cooled. Store only if stabilized. Airtight. R: S: UN Hazard Class: 3 UN Packing Group: III SEE IMPORTANT INFORMATION ON BACK ICSC: 0857 Prepared in the context of cooperation between the International Programme on Chemical Safety & the Commission of the European Communities (C) IPCS CEC 1994. No modifications to the International version have been made except to add the OSHA PELs, NIOSH RELs and NIOSH IDLH values.

International Chemical Safety Cards CYCLOPENTADIENE ICSC: 0857 I M P O R T A N T D A T A 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 will readily polymerize to dimer with 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, causing fire and explosion hazard. OCCUPATIONAL EXPOSURE LIMITS: 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 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 irritates the eyes and the respiratory tract. EFFECTS OF LONG-TERM OR REPEATED EXPOSURE: PHYSICAL PROPERTIES 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 ENVIRONMENTAL DATA N O T E S 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. Transport Emergency Card: TEC (R)-30G35 ADDITIONAL INFORMATION ICSC: 0857 CYCLOPENTADIENE (C) IPCS, CEC, 1994

IMPORTANT LEGAL NOTICE: Neither NIOSH, the CEC or the IPCS nor any person acting on behalf of NIOSH, the CEC or the IPCS is responsible for the use which might be made of this information. This card contains the collective views of the IPCS Peer Review Committee and may not reflect in all cases all the detailed requirements included in national legislation on the subject. The user should verify compliance of the cards with the relevant legislation in the country of use. The only modifications made to produce the U.S. version is inclusion of the OSHA PELs, NIOSH RELs and NIOSH IDLH values.