Methyl isocyanate

  • Isocyanatomethane
  • Isocyanic acid, methyl ester
  • Methyl ester of isocyanic acid
  • MIC
Formula CH3NCO
Structure

Registry Numbers and Inventories.
CAS 624-83-9
EC (EINECS/ELINCS) 210-866-3
EC Index Number 615-001-00-7
EC Class Extremely flammable; Toxic; Irritant
RTECS NQ9450000
RTECS class Mutagen; Reproductive Effector; Human Data; Primary Irritant
UN (DOT) 2480
Merck 12,6163
Beilstein/Gmelin 605318
Beilstein Reference 4-04-00-00247
RCRA P064
Swiss Giftliste 1 G-2470
Canada DSL/NDSL NDSL
US TSCA Listed
Austrailia AICS Listed

Properties.
Formula C2H3NO
Formula mass 57.05
Melting point, °C -80
Boiling point, °C 39
Vapor pressure, mmHg 531 (25 C)
Vapor density (air=1) ~2
Critical temperature 218
Critical pressure 55
Density 0.9744 g/cm3 (15 C)
Solubility in water 100 g/L
Refractive index 1.3718 (14.9 C)
Partition coefficient, pKow 0.83
Heat of vaporization 26.8 kJ/mol
Heat of combustion -1128 kJ/mol

Hazards and Protection.
Storage Keep cool, no sparks, flames. Store in areas separated from oxidizers. store in stainless steel receptacles, nickel, or perfectly vitrified materials.
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 protective gloves, clothing and goggles.
Respirators Wear positive pressure self-contained breathing apparatus (SCBA).
Small spills/leaks Keep sparks, flames, and other sources of ignition away. Keep material out of water sources and sewers. Build dikes to contain flow as necessary. Attempt to stop leak if without undue personnel hazard. Use water spray to knock-down vapors.
Stability Exploded violently when dropped on hot surface. Dried out material may explode if exposed to heat, flame, or shock. Runoff to sewer may create fire or explosion hazard.
Incompatibilities Reacts rapidly with acids and bases (including amines) Attacks some plastics, rubbers, and coatings.

Fire.
Flash Point,°C -7
Autoignition, °C 534
Upper exp. limit, % 26
Lower exp. limit, % 5.3
Fire fighting Material is extremely hazardous to health but areas may be entered with extreme care. Full protective clothing, including self-contained breathing apparatus (coat, pants, gloves, boots, and bands around legs, arms and waist) should be provided. No skin surface should be exposed. Stay away from ends of tanks. Do not get water inside container. Spray cooling water on containers that are exposed to flames until well after fire is out. Withdraw immediately in case of rising sound from venting safety device or any discoloration of tank due to fire.Small fires: dry chemical, carbon dioxide, water spray, or foam. Large fires: water spray, fog, or foam.
Fire potential Very flammable.
Hazards May be ignited by heat, sparks, or flames. Vapors may travel to a source of ignition and flash back. Container may explode violently in heat of fire. Vapor explosion and poison hazard indoors, outdoors, or in sewers.
Combustion products Methyl isocyanate vapors and hydrogen cyanide will be emitted in a fire.
NFPA Health 4
  Flammability 3  
  Reactivity 2  
  Special W

Health.
Exposure limit(s) NIOSH REL: TWA 0.02 ppm (0.05 mg/m3)[skin] OSHA PEL: TWA 0.02 ppm (0.05 mg/m3) [skin] IDLH 3 ppm
Poison_Class 1
Exposure effects Acute exposure may cause dyspnea. Pulmonary edema-induced hypoxia may produce CNS depression. There is conflicting data as to whether methyl isocyanate is fetotoxic, however, it crosses the placental barrier. Reports from Bhopal, India and animal studies suggest a high degree of adverse reproductive effects and teratogenicity.
   Ingestion Gastrointestinal irritation and vomiting may occur.
   Inhalation TOXIC; inhalation, ingestion or contact (skin, eyes) with vapors, dusts or substance may cause severe injury, burns, or death. Effects may be delayed.
   Skin Skin irritation is likely. Contact can cause chemical burns (sittig, 1991; hsdb, 2001).
   Eyes Contact with the eye is extremely irritating and may cause permanent damage with cataract formation, trachoma and chronic blepharitis.

First aid
 
   Ingestion Administer charcoal as a slurry (240 ml water/30 g charcoal). Usual dose: 25 to 100 g in adults/adolescents.
   Inhalation Move victim to fresh air. Apply artificial respiration if victim is not breathing. Do not use mouth-to-mouth method if victim ingested or inhaled the substance; induce artificial respiration with the aid of a pocket mask equipped with a one-way valve or other proper respiratory medical device. Administer oxygen if breathing is difficult.
   Skin Remove and isolate contaminated clothing and shoes. Immediately flush with running water for at least 20 minutes. For minor skin contact, avoid spreading material on unaffected skin.
   Eyes Immediately flush with running water for at least 20 minutes.

Transport.
UN number 2480
Response guide 155
Hazard class 6.1
PRTC T
Packing Group I  
USCG CHRIS Code MIS  
USCG Compatatibility Group 12 Isocyanates
Std. Transport # 4927009