Marines and Sailors with 2nd Medical Battalion air out their uniforms during a quarterly gas chamber qualification on Camp Lejeune, N.C., Sept. 8, 2017. - Marines and Sailors with 2nd Medical Battalion check the proper fit of their masks during a quarterly gas chamber qualification on Camp Lejeune, N.C., Sept. 8, 2017. Service members with the unit qualify quarterly to ensure they are effectively able to use protective equipment in a contaminated environment. (U.S. Marine Corps photo by Cpl. Ashley Lawson)