U.S. Marines stationed at Marine Corps Air Station (MCAS) Yuma, conduct their annual Chemical, Biological, Radiological and Nuclear Defense (CBRN) Training at the MCAS Yuma Gas Chamber July 26, 2018. The gas chamber is a controlled environment in which a non-lethal gas is released. This trains Marines to have confidence in their gear and become familiar with the effects of gas. (U.S. Marine Corps Photos by Lance Cpl. Sabrina Candiaflores) - U.S. Marines stationed at Marine Corps Air Station (MCAS) Yuma, conduct their annual Chemical, Biological, Radiological and Nuclear Defense (CBRN) Training at the MCAS Yuma Gas Chamber July 26, 2018. The gas chamber is a controlled environment in which a non-lethal gas is released. This trains Marines to have confidence in their gear and become familiar with the effects of gas. (U.S. Marine Corps Photos by Lance Cpl. Sabrina Candiaflores)