From Dungeons of Dredmor Wiki

This powerful acid burns flesh and armour alike.

Duration: 5 turns

Damage: 6 and 2 for every turn.

Secondary effect: -4 -1 -1 -1 and causes bleeding

This spell is currently a side-effect of certain Traps, drinking some alchemical reagents, one possible result of drinking from a Fountain and can be an enchantment on an Artifact weapon. It is the secondary effect of the Acid Ampoule Bolt.