Riot control agents are less-lethal lachrymatory agents used for riot control. Most commonly used riot control agents are pepper spray and various kinds of tear gas. These chemicals disperse a crowd that could be protesting, in a riot, or to clear a building. They can rapidly produce sensory irritation or disabling physical effects which usually disappear within 15 minutes (for tear gas) and up to 2 hours (for pepper spray) following termination of exposure. They can also be used for chemical w… (More on Teargas)