A chemical explosive.
Throwable capsule containing several chemical substances. When the capsule hits a target, the chemicals inside it mix to produce a corrosive gas.
While the gas is airborne, it slowly eats away nearby objects.
Because it destroys biomatter as well as machines, it has been classified as a highly dangerous weapon, banned from use by international treaty.
However, as circumstances worsened, its use was permitted under special exemption only during wartime.