This webpage is maintained by the Centers for Disease Control and Prevention (CDC). The webpage provides information and resources on Methyl Isocyanate. "Exposure to methyl isocyanate typically occurs through inhalation or dermal absorption. Toxicity might develop over 1 to 4 hours after exposure. Signs and symptoms of methyl isocyanate typically include cough, dyspnea, chest pain, lacrimation, eyelid edema, and unconsciousness. These effects might progress over the next 24 to 72 hours to include acute lung injury, cardiac arrest, and death (1-4)."
Centers for Disease Control and Prevention: http://www.cdc.gov/