Marine recruits get gassed inside chamber during chemical defense training

Recruits of Charlie Company, 1st Recruit Training Battalion, shake their heads during chemical warfare defense training June 3, 2014, on Parris Island, S.C. The recruits shook their heads and performed other exercises to prove their gas masks worked despite vigorous activity. Later, each recruit had to temporarily break the airtight seal, exposing himself to nonlethal tear gas used to simulate the stresses of a chemically contaminated environment. Recruits then resealed their masks and cleared the gas. U.S. Marine Corps photograph by Cpl. Octavia Davis, released. (This image was released by the United States Marine Corps with the ID 140603-M- RV272-298. This file is a work of a sailor or employee of the U.S. Navy, taken or made as part of that person's official duties. As a work of the U.S. federal government, it is in the public domain in the United States.)