Coughing is uncontrollable, and sneezing is violent and persistent. Nasal secretion is greatly increased, and quantities of ropy saliva flow from the mouth. Nausea and vomiting are prominent. Mental depression may occur during the progression of symptoms. There are usually no long-term effects from vomiting agent exposures, and symptom generally disappear within 20 min to 2 h. Like other riot-control agents, deaths have occurred from exposure to high concentrations in enclosed areas.