Fiji Water

Fiji Water is a substance generated only in Layer 4 of the Hole. While initially nonreactive on its own, when combined with plastic into a bottle of Fiji Water, it becomes highly reactive. When the plastic surrounding the Fiji Water is broken, the Fiji Water reacts with chemicals in the air and causes a high-energy explosion.

There is no visible difference between Fiji Water and normal water, even on molecular scale. The reactivity of Fiji Water is as of yet unexplained.