Original U.S. WWII 1943 dated Experimental Ethocellulose Plastic Canteen In an effort to manufacture a non-metallic a canteen during World War Two, the US government attempted to manufacture a plastic canteen using Dow Chemical's Ethyl Cellulose Plastic product, called Ethocel. The canteen was manufactured by several government suppliers. Canteens started to be manufactured the middle of 1942 and were discontinued by 1944.The canteens were typically issued to Pacific Theater Forces. This was a common canteen to find on the USMC web belt or discarded along the route of the Marine advance. The problem with the canteens was that they tended to eventually develop heat stress cracks. They also made the water they contained taste like bitter plastic. In order to combat the horrible taste of the water, soldiers routinely mixed baking powder in with the water when filling the canteen. Later plastics would not have this problem, but this design was unfortunately ahead of its time. 
"modified cap"