Refrigerator stories, July 2000:
The stories below came to a safety listserv in response to a query from Richard Benton, Fire Marshal at the University of California, San Diego: "Does anyone have direct knowledge of instance(s) of fires involving flammable liquids stored in either cold rooms or refrigerators other than full-on explosion-proof units? We are constantly challenged by our faculty as to why we won't let them use commercial (home-type) refrigerators, nor allow them to try to field-modify such units to eliminate (their idea) all hazards."
Note: I'm not sure I'd call it "field-modification" but here at Purdue we do allow in-house modification of refrigerators and freezers by the Physical Facilities Refrigeration Shop. They remove the light wiring and move the thermostat to the exterior of the unit. It costs around $150 or so at latest inquiry, and it is my understanding that this renders the unit adequately "flammable-safe." You must still keep containers of flammables CLOSED SECURELY. And IT VOIDS YOUR WARRANTY, of course. If this is not acceptable you must simply purchase a flammable safe unit from a manufacturer. Self defrosting freezer units are not modifiable (I think).
From Penn State:
From U Colorado:
From U Virginia:
We have since removed all household type refrigerators that were being used for storage of flammable compounds in labs . We do not recommend the field modified units for this type of storage. They should be explosion proof type which are hard wired ( not plugged into a receptacle ). For more info contact me @ Tim Ritchey, UVa Fire Marshal, 804 982-4914, fire-safety@virginia.EDU
More from U Virginia, (on same incident??):
From U Maryland:
One day, one of the refrigerators experienced an explosion that ripped off one of the hinges and increased the interior capacity by pushing the walls & top out about 6-8 inches. One would think that the PI would have gotten the message but about a month later, a second explosion occurred in the same suite of labs.
In this one, the door actually came off, exited thru a window, and landed in the parking lot, 3 stories down.
In another lab, a month later, a similar incident occurred at 3AM, less explosion, more fire. Totally gutted the entire lab and sent several fire fighters to the hospital. The exact material was never determined (too many burned & broken bottle in the debris). We were very fortunate that the fire did not involve the six 5-gal cans of ether that were sitting within a few feet of the refrigerator (the cans bulged but didn't fail).
Right after this, the U. made a mass purchase of approved refrigerators & freezers and flammable liquid storage cabinets - and funded complete retrofit of automatic sprinklers in several major lab buildings.
Stick to your guns - there are too many things that can cause the spark necessary for a solvent explosion in these non-approved refrigerators - thermostats, motors, switches, lights, etc. The only way to safely field modify them is to take out all of these things and put a block of dry ice inside.
From private sector, on use of "lab safe," flammable refrigerator,"
and "explosion proof."
Remember that there are two types of refrigerators approved for use in storage of flammable liquids or gases.
Explosion proof refrigerators are designed for use in an area where flammable vapors or gases may be present in the environment around the unit. They have explosion-proof electrical equipment and junction boxes and must be hard-wired into the buildings electrical system using approved methods. These units are usually quite expensive.
Flammable-safe refrigerators have specially designed interior parts to prevent flammable vapors or gases from contacting internal ignition sources. They are not approved for use in an environment where flammable vapors or gases may be present, because ignition sources on the exterior of the refrigerator may not be vapor-tight. These units are connected to an electrical outlet using a standard cord and plug assembly.
Flammable-safe refrigerators are usually much less expensive than explosion-proof models. Specifying an explosion-proof refrigerator in a lab where flammable vapors won't be present in ignitable quantities may be a waste of funds that may be applied elsewhere. Specifying a flammable-safe refrigerator in a lab where flammable vapors are present may result in an ignition, fire, or explosion.
Laboratory personnel frequently ask for an explosion-proof refrigerator when only a flammable-safe model is needed. Of course, all lab refrigerators should be labeled as to suitability for flammable storage.