Purpose: Riot-control agents
History: Developed in 1928 by American scientists Ben Corson and Roger Stoughton (hence its name), CS is the most commonly used riot-control agent today. Perhaps the most famous and controversial mass use of CS came in 1993 during a standoff at the Branch Davidian compound near Waco, Texas, that ended with the death of more than 70 members of the religious group. The chemical effects of CS were not implicated in those deaths; the wisdom of its use inside a building in the compound was widely questioned, and some experts believe that use may have been a factor in the uncontrollable fire that killed the Branch Davidians.
For a chemical to be effective and safe for use in riot control, two criteria must apply: The chemical must be non-lethal, creating great discomfort while disabling human targets and inflicting damage that is short-lasting and treatable without hospital care. Judged by this criteria, the long-standing use of CS as a riot-control agent is justified. In sufficient quantities, CS stings exposed skin, creates tightness in the chest and shortness of breath, and produces intense tearing and burning of the eyes. Moreover, exposure to adequate CS removes the victim’s ability to communicate and control physical actions. CN is more toxic and more dangerous than CS; its use has resulted in five deaths, according to the National Institutes of Health.
Were they used in Syria? CS is used globally by domestic security forces for crowd dispersal. Syria uses riot-control agents widely. Reports of such use in Syria frequently conflate CS with CN. By the late 1950s, CN had lost favor around the world to the safer CS, but CN is still used in some countries—one likely being Syria.