International Chemical Safety Cards PROPYNE ICSC: 0560 Allylene Methyl acetylene C3H4 / CH3C=CH Molecular mass: 40.07 (cylinder) ICSC #    0560 CAS #     74-99-7 RTECS # UK4250000 UN #        1954 April 11, 1997 Peer reviewed TYPES OF HAZARD/ EXPOSURE ACUTE HAZARDS/ SYMPTOMS PREVENTION FIRST AID/ FIRE FIGHTING FIRE Extremely flammable. NO open flames, NO sparks, and NO smoking. Shut off supply; if not possible and no risk to surroundings, let the fire burn itself out; in other cases extinguish with water spray. EXPLOSION Gas/air mixtures are explosive. Closed system, ventilation, explosion-proof electrical equipment and lighting. Prevent build-up of electrostatic charges (e.g., by grounding) if in liquid state. Use non-sparking handtools. Prevent build-up of electrostatic charges (e.g., by grounding). In case of fire: keep cylinder cool by spraying with water. Combat fire from a sheltered position. EXPOSURE  •INHALATION Dizziness. Headache. Nausea. Unconsciousness. Local exhaust or breathing protection. Fresh air, rest. Artificial respiration if indicated. Refer for medical attention. See Notes.  •SKIN ON CONTACT WITH LIQUID: FROSTBITE. Cold-insulating gloves. ON FROSTBITE: rinse with plenty of water, do NOT remove clothes.  •EYES Face shield. First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then take to a doctor.  •INGESTION SPILLAGE DISPOSAL STORAGE PACKAGING & LABELLING Evacuate danger area! Ventilation. Remove all ignition sources. NEVER direct water jet on liquid. (Extra personal protection: chemical protection suit including self-contained breathing apparatus). Fireproof. Cool. R: S: UN Hazard Class: 2.1 SEE IMPORTANT INFORMATION ON BACK ICSC: 0560 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 PROPYNE ICSC: 0560 I M P O R T A N T D A T A PHYSICAL STATE; APPEARANCE: COLOURLESS COMPRESSED GAS , WITH CHARACTERISTIC ODOUR. PHYSICAL DANGERS: The gas is heavier than air and may travel along the ground; distant ignition possible. As a result of flow, agitation, etc., electrostatic charges can be generated. CHEMICAL DANGERS: The substance decomposes on heating and increasing pressure , causing fire and explosion hazard. OCCUPATIONAL EXPOSURE LIMITS: TLV: 1000 ppm; 1640 mg/m3 (ACGIH 1996). OSHA PEL: TWA 1000 ppm (1650 mg/m3) NIOSH REL: TWA 1000 ppm (1650 mg/m3) NIOSH IDLH: 1700 ppm LEL ROUTES OF EXPOSURE: The substance can be absorbed into the body by inhalation. INHALATION RISK: On loss of containment this gas can cause suffocation by lowering the oxygen content of the air in confined areas. EFFECTS OF SHORT-TERM EXPOSURE: The substance irritates the respiratory tract. Rapid evaporation of the liquid may cause frostbite. Exposure could cause lowering of consciousness. EFFECTS OF LONG-TERM OR REPEATED EXPOSURE: PHYSICAL PROPERTIES Boiling point: -23.2°C Melting point: -102.7°C Relative density (water = 1): 0.70 Solubility in water, g/100 ml: 0.36 Vapour pressure, kPa at 20°C: 521 Relative vapour density (air = 1): 1.4 Flash point: Flammable Gas Explosive limits, vol% in air: 2.4-11.7 ENVIRONMENTAL DATA N O T E S High concentrations in the air cause a deficiency of oxygen with the risk of unconsciousness or death. Check oxygen content before entering area. After use for welding, turn valve off; regularly check tubing, etc., and test for leaks with soap and water. The measures mentioned in section PREVENTION are applicable to production, filling of cylinders, and storage of the gas. Transport Emergency Card: TEC (R)-20G41 NFPA Code: H2; F4; R2; ADDITIONAL INFORMATION ICSC: 0560 PROPYNE (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.