Generic chemical munitions deal no direct damage, but do form AOE clouds as smoke shells do.
However, instead of the SMK modifier, these clouds possess PSN, which inflicts Poisoned.
Chemical shells consist of a hollow steel container filled with chemical agents, which are dispersed with a small explosive charge. These munitions saw widespread use during World War I and almost at the end of World War II. The shell itself is inexpensive and simple to manufacture, but exotic poison gases which require special storage such as Sarin can drive up costs immensely.