Airman 1st Class Kendrick, 187th Fighter Wing emergency manager, exits a bus filled with non-lethal chlorobenzalmalononitrile gas, or CS gas, during the Global Dragon deployment for training at the Guardian Center, Perry, Ga., March 12, 2015. CS gas, also known as tear gas, was discovered by Ben Corson and Roger Stoughton in 1928. (U.S. Air National Guard photo by Senior Airman Cody Martin/released)