I see in the news that a New Bedford, Mass. fishing boat hauled up some mustard gas shells. They were in an area, the news said, used to dump gas shells after WWII. Although we know it was never [?]used in WWII ,we were ready in case the Germans used gas. Mustard gas was frequently carried in merchant ships. My father, an Armed Guard gunnery officer said that when gas was carried it was aways stowed in the forepeak, all the way forward in the ship. I don't know if the gas was unloaded and stored in Europe or remained on the ships. The gas was always accompanied by an Army Chemical Corps Lieutenant.
Google up the Bari Italy raid, and the SS John Harvey. This was a shipment of the "new and improved" mustard gas of WW2 with a different base. It smelled like roasted garlic, not rotten eggs when it was released. I believe it was because the base chemical was shifted from sulfur to nitrogen, but I could be wrong. There is no telling how much of this stuff was stockpiled around on American/Allied bases "just in case" the Axis powers decided to use their stockpiles. And oh, BTW we had about 12,000 tons of Tabun stockpiled at DuPont as well. The IG Farben people weren't the only ones with a "nerve agent" to worry about. And Hitler knew we had it too. Pissed him off to no end when he was informed that both Tabun and Sarin were not "secret weapons".