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.
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.
From U Maryland:
About 12-15 years ago, we had a series of "I told you so" incidents
involving non-approved refrigerators used to store flammable solvents. The
department involved had been told not to purchase or use these residential type
refrigerators that had come from the state surplus property unit.
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."
I have noticed many references in a recent thread regarding explosion-proof
refrigerators. This generic term is often used to describe two types of refrigerators used
in laboratories.
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. |
