Comment linked here
I've searched online, but the results are flooded by pages about the Allies' plans to use gas, not Japanese use of actual gas.
EDIT: I'm talking about use against Allied troops in a combat zone, not necessarily during the occupation of China.
EDIT2: His comment is pasted below:
Only to the extent that we had to wear gas masks and the masks were so tight to your face, your skin shriveled. You had a tendency to put a finger under the mask to get some fresh air and in doing so you permitted the gas to get in the mask. I did this and my eyes were burning and watery. It also caused me to vomit. The gas attack lasted for a day and a half. The Japanese dropped it from planes.
The only two people on ship that escaped the gases were the commanding officer and the lieutenant commander. They escaped it by going into the refrigerating room. It was the only area aboard ship that wasn't affected by the gas.
EDIT3: Thanks /u/freddiedie
The OP of the AMA just included the following edit in the linked comment: "(Grandson: The gas was from the United States using it as a screen to hide the ships. Apologies for not correcting this earlier.)" As well as including the following correction: "The gas attack lasted for a day and a half.
The Japanese dropped it from planesThe United States dropped it as a screen for the ships."
There's no actual historical evidence for the hostile use of gas against Americans by any belligerent power. The Japanese did use gas in China, but there's no documented case of a gas attack against US troops anywhere. Accidents in handling gas did occur, but I can't find a record of the USS Nashville ever being exposed to chemicals.
There are numerous accounts of Americans ground troops donning gas masks in response to low-hanging fumes from artillery and fire but it would require another source to confirm it on the Nashville. I have no idea if this was ever standard practice on Navy ships, as well, in response to fumes building up in sustained bombardments. I would think a ship's movement would provide enough wind to blow fumes away from a ship.
Seems to be a vet misremembering things.
The OP of the AMA just included the following edit in the linked comment:
"(Grandson: The gas was from the United States using it as a screen to hide the ships. Apologies for not correcting this earlier.)"
As well as including the following correction:
"The gas attack lasted for a day and a half. ~~The Japanese dropped it from planes .~~The United States dropped it as a screen for the ships."
Wouldn't he himself be a primary source, if we could verify his placement and what he says?