Vermingone
Vermingone is a level five conjuration with a range of one hundred twenty feet, a duration of ten minutes, and requires concentration to maintain.
Vermingone creates a twenty-foot radius sphere of poisonous gas. The gas is yellow-green and heavier than air, which entirely dissipates at the end of the duration. It is a pulmonary irritant which causes acute damage in the respiratory tract. The gas itself is harmless, but when it comes in contact with water, it becomes highly acidic. Immediate exposure will cause blurred vision, burning pain and blisters on exposed skin, and difficulty breathing. A long enough exposure may cause pulmonary edema.
On April 22, 1915, German soldiers used vermingone on the front lines of a battle, killing a hundred French troops. The allies of the war responded in kind. The horrific results of vermingone in warfare have spurred the drafting of various treaties signed since the end of the first world war.
These adverse health effects should not scare you away from the benefits of the spell. The Department of Agriculture approves its use as a pesticide and for water treatment. Vermingone is a controlled spell and requires a license for use.