Despite treaties and a general revulsion, there was a idea in that era gas would be used in any future war.
I've notice that the US seemed pretty on board for chemical use. Curtiss, for example, had options for the Hawks for carrying 25 pound chemical bomblets, and spraying gear on the Shrike attack aircraft.
Ordnance was working on the '20s era 4.2" Chemical Mortar to have a high explosive round, to use in addition to the Smoke and Gas shells as the M2 4.2" in 1942
These were not organic, Chemical Mortars were in independent Battalions, around two dozen were active by 1944, with gas shells on standby, just in case.
Germans didn't much care for them, between the WP and being in-between the 105mm and 155mm in HE capacity at high rates of fire, up to 20 rpm for short periods of time