Flammable and hazardous location refrigerators

From U Colorado:
Here at the University of Colorado Health Sciences Center, we have not experienced any incidents of flammable liquid fires due to storage in cold rooms or standard refrigerators (even though we know some researchers are doing it). Regardless, has always been campus policy that flammable liquids may only be stored in approved "explosion-proof" units. We also have had researchers question the rationale behind the policy. Since the nature of research often requires the lab to use cooled material, we recently decided to allow an exception for limited quantities (500 ml) in sealed plastic containers (with a 25% vapor space for expansion) and provided that secondary non-breakable containment is used. With these safeguards, it is difficult to imagine a fire/explosion. [LAS note -- in regular household units?! This sounds like a really bad idea.]