Explosion proof refrigeration

From Penn State:
One of our labs experienced an explosion and fire resulting from the temporary storage of solution samples (alcohol / ethanol etc.) in a non-explosion proof refrigerator. The amount of materials placed in the refrigerator was very small. One lab was conducting some house cleaning and an individual placed the solutions in another labs refrigerator thinking it was explosion proof. Fortunately, no one was in the lab when the explosion occurred. The loss due to the explosion, fire and smoke was around $200,000 in addition to the time the lab was unable to be used during renovation and cleanup.