A U.S. Army Soldier breaks a chlorobenzalmalononitrile (CS) tablet to fill the room with gas at Joint Base Langley-Eustis, Va., Oct. 6, 2016. The confidence training gave the Soldiers experience with the effects of chlorobenzalmalononitrile gas and how to properly don their protective equipment. (U.S. Air Force photo by Airman 1st Class Derek Seifert) (Photo by Airman 1st Class Derek Seifert)