![U.S. Marine Lt. Col. Wilfred Rivera prepares to engage targets while wearing a gas mask during combat marksmanship training aboard Camp Pendleton, Calif., Feb. 9, 2015. Rivera is the commanding officer of U.S. Marine Lt. Col. Wilfred Rivera prepares to engage targets while wearing a gas mask during combat marksmanship training aboard Camp Pendleton, Calif., Feb. 9, 2015. Rivera is the commanding officer of](https://c8.alamy.com/comp/HF2X9P/us-marine-lt-col-wilfred-rivera-prepares-to-engage-targets-while-wearing-HF2X9P.jpg)
U.S. Marine Lt. Col. Wilfred Rivera prepares to engage targets while wearing a gas mask during combat marksmanship training aboard Camp Pendleton, Calif., Feb. 9, 2015. Rivera is the commanding officer of
![A U.S. Marine Corps recruit with Company K, breaks the seal to a M40 gas mask inside the gas chamber at Marine Corps Base Camp Pendleton, California, Oct. 15, 2018. The gas A U.S. Marine Corps recruit with Company K, breaks the seal to a M40 gas mask inside the gas chamber at Marine Corps Base Camp Pendleton, California, Oct. 15, 2018. The gas](https://c8.alamy.com/comp/R1M9FA/a-us-marine-corps-recruit-with-company-k-breaks-the-seal-to-a-m40-gas-mask-inside-the-gas-chamber-at-marine-corps-base-camp-pendleton-california-oct-15-2018-the-gas-chamber-trains-recruits-how-to-properly-use-the-m40-gas-mask-and-respond-to-potential-chemical-and-biological-threats-R1M9FA.jpg)
A U.S. Marine Corps recruit with Company K, breaks the seal to a M40 gas mask inside the gas chamber at Marine Corps Base Camp Pendleton, California, Oct. 15, 2018. The gas
![Vietnam War. Us Marine Wearing Gas Mask While Waiting To Enter A Viet Cong Tunnel 22 Miles South Of Danang History (18 x - Walmart.com - Walmart.com Vietnam War. Us Marine Wearing Gas Mask While Waiting To Enter A Viet Cong Tunnel 22 Miles South Of Danang History (18 x - Walmart.com - Walmart.com](https://i5.walmartimages.com/asr/4f18671f-19ff-472f-8557-90421fb41197_1.2c610dafa351cba30563957dea26c9c4.jpeg)
Vietnam War. Us Marine Wearing Gas Mask While Waiting To Enter A Viet Cong Tunnel 22 Miles South Of Danang History (18 x - Walmart.com - Walmart.com
![2d Marine Division Twitterren: "Gas Gas Gas! . U.S. Marines conduct a gas mask run aimed to build unit readiness and cohesion, while also familiarizing themselves with conducting strenuous activity while wearing 2d Marine Division Twitterren: "Gas Gas Gas! . U.S. Marines conduct a gas mask run aimed to build unit readiness and cohesion, while also familiarizing themselves with conducting strenuous activity while wearing](https://pbs.twimg.com/media/DsZNNn2U0AEwmes.jpg)
2d Marine Division Twitterren: "Gas Gas Gas! . U.S. Marines conduct a gas mask run aimed to build unit readiness and cohesion, while also familiarizing themselves with conducting strenuous activity while wearing
![Amazon.com: Posterazzi U.S. Marine Corps reservists in camouflage and gas masks assisting each other with their hood straps Poster Print, (22 x 34): Posters & Prints Amazon.com: Posterazzi U.S. Marine Corps reservists in camouflage and gas masks assisting each other with their hood straps Poster Print, (22 x 34): Posters & Prints](https://images-na.ssl-images-amazon.com/images/I/61BbS7hfkCL._AC_SY741_.jpg)
Amazon.com: Posterazzi U.S. Marine Corps reservists in camouflage and gas masks assisting each other with their hood straps Poster Print, (22 x 34): Posters & Prints
U.S., ROK Marines test CBRN response during gas attack > United States Marine Corps Flagship > News Display
![US Marine in MOPP gear inc gas mask uses M272 Chemical Agent Water Testing Kit ( lewisite, nerve agents, cyanide and mustard Stock Photo - Alamy US Marine in MOPP gear inc gas mask uses M272 Chemical Agent Water Testing Kit ( lewisite, nerve agents, cyanide and mustard Stock Photo - Alamy](https://c8.alamy.com/comp/D18XN7/us-marine-in-mopp-gear-inc-gas-mask-uses-m272-chemical-agent-water-D18XN7.jpg)
US Marine in MOPP gear inc gas mask uses M272 Chemical Agent Water Testing Kit ( lewisite, nerve agents, cyanide and mustard Stock Photo - Alamy
![US Marine Corps reservists in camouflage and gas masks Wall Art, Canvas Prints, Framed Prints, Wall Peels | Great Big Canvas US Marine Corps reservists in camouflage and gas masks Wall Art, Canvas Prints, Framed Prints, Wall Peels | Great Big Canvas](https://static.greatbigcanvas.com/images/singlecanvas_thick_none/stocktrek-images/us-marine-corps-reservists-in-camouflage-and-gas-masks,stk103158m.jpg?max=700)