Unit Drills With Gas Mask

Cpl. David M. Hernandez, 11th Marine Expeditionary Unit, uses a burner to activate tear-gas particles in a chamber here March 10 during training in which approximately 100 unit members drilled with XM50 joint-service general-purpose masks. Hernandez, 22, from Orange, Calif., is a chemical-biological-radiological-nuclear defense Marine serving with the unit.
Photo by Gunnery Sgt. Scott Dunn