Do not induce vomiting. Get medical assistance immediately. Acetonitrile is metabolized to cyanide. Patients with significant exposures must be observed for signs of cyanide poisoning and treated accordingly. Dangerous fire hazard when exposed to heat or flame.
Vapor is heavier than air and danger of flashback exists.
Fire may produce toxic fumes. Always wear Self Contained Breathing Apparatus. Eliminate sources of ignition. Isolate the spill area. Stop leak in a safe and practical manner.