Two people were sent to hospital with minor chemical burns after a lithium battery exploded at a pipeline service company in Mill Woods last night. 

Edmonton firefighters were on scene just after six o'clock on Dec.13. 

The fire put a hole in the roof of the company's building.

District Fire Chief Pat Grier

District Fire Chief Pat Grier (CBC/Doug Steele)

District Fire Chief Pat Grier said firefighters had to be careful fighting the fire because of how lithium reacts to water. 

Lithium can catch on fire or explode when it comes into contact with combustible substances and water. 

"We've evacuated the building, we don't want anyone exposed to the smoke," Grier said from the scene last night.

It took about two hours to extinguish the fire. 

The extent of the damages is not yet known.