Coal Residue
HAZARD 2 +9
Combustible material can ignite and burn ferociously.
DC 15 Mining Lore (trained) to spread inert material over the area or DC 18 Survival to pry up enough of the material to prevent a chain reaction.
Ignite (fire)
An effect in the area deals at least 8 electricity or 4 fire
The coal residue rapidly ignites, dealing 4d6 fire damage to all creatures in the area (DC 18 basic Reflex save). The area burns for 1 minute, during which creatures in the area are Concealed, other creatures are concealed to them, and creatures who end their turn in the area take 1d6 fire damage.
Pathfinder #193: Mantle of GoldOGL