TL;DR
Placeable barrels, that contain the fluids available. Some contents are explosive.What ?
You can place barrels in the world and when they contain light oil or petroleum gas they explode when they get damaged.Other fluids would just spill with an animation.
They could leave a burning area and when they have a range, they could damage other barrels nearby.
I know its a rather useless suggestion, but I think it could be fun to use it for combat.
Or for destruction.