Riot control agents respiratory tract effects

By any route of administration, the effects are slower in onset and longer in duration than typical riot control agents such as CS (o-chloro-benzylmalono-nitrile). Vomiting agents are irritants upon initial exposure. The slow onset for DM allows for the absorption of much more DM before a warning is perceived. The estimated threshold concentrations for irritation of the throat, lower respiratory tract, and initiation of the cough reflex are 0.38, 0.5, and 0.75 mg m respectively. 

Riot control agents such as CN are those that cause disabling physiological effects when they come into contact with the eyes or skin, or when inhaled. They have the capacity to cause intense sensory irritation of the skin and mucous membranes of the eye and respiratory tract. They are peripheral sensory irritants that pharmacologically interact with sensory nerve receptors in skin and mucosal surfaces at the site of contamination resulting in local pain and discomfort sensations with associated reflexes. The reflex associated with the inhalation exposure of irritants is the Kratschmer reflex. This reflex causes apnea, bradycardia, and a biphasic fall and rise in aortic blood pressure. 

The riot control agent known as CR (dibenz(b,f)-1 4-oxazepine) is a relatively new compound, first synthesized in 1962 by Higginbottom and Suschitzkey. CR is more potent and less toxic than CS. Because of the low vapor pressure of CR solution, no respiratory tract effects are anticipated from its use. The LCt5g for animals exposed to grenade-generated smokes was found to be 167,500 mg min/m3. The estimated LCt50 for humans is probably higher than 100,000 mg min/m3.24... 

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