Methyl Isocyanate was the chemical that was involved in the Union Carbide spill in Bhopal, India in 1984. The incident killed 2,000 people (who died primarily from pulmonary edema) and more than 170,000 became ill (chronic bronchitis and pneumonia, among other wonderful things). An abnormally high rait of stillbirths and spontaneous abortions were reported among survivors.
Reproductive effects, such as leukorrhea, pelvic inflammatory disease, excessive menstrual bleeding, and suppression of lactation have been known to show up in individuals exposed to Methyl Isocyanate. There is no evidence as of yet as to whether or not it is carcinogenic in humans.
Methyl Isocyanate is a colorless liquid that has a sharp odor. The odor threshold for Methyl Isocyanate is 2.1 ppm. The chemical formula for Methyl Isocyanate is C2H3NO, and the molecular weight is 57.05 g/mol. The vapor pressure for Methyl Isocyanate is 348 mm Hg at 20 C. It is often used as a precursor for carbamate insecticides and herbicides.
Methyl Isocyanate is a Class I flammable liquid, and produces toxic gases as a by-product of combustion. Another great thing about Methyl Isocyanate is that it is water reactive (meaning that if it were to catch fire, you couldn't put the fire out with water. You would have to use sand, foam or limestone.) It is absorbed through the skin. Methyl Isocyanate will cause vomiting, respiratory damage and burns of mucous membranes upon exposure.
The boiling point of Methyl Isocyanate is 39C, a flash point of -7C, a melting point of -45C, a relative density of .96 (where water is 1.0) and a vapor pressure of 46.4 kPa at 20C.
Methyl Isocyanate would classify as (like my HAZMAT proffesor says) as "methyl ethyl bad shit."
Sources:
http://www.epa.gov/ttn/uatw/hlthef/methylis.html
http://www.itcilo.it/english/actrav/telearn/osh/ic/624839.htm