A flammable refrigerator would have avoided this damage caused by a thermostat spark

Improperly specified or used lab refrigerators and lab freezers pose a significant threat to personnel and equipment when volatile vapors or gases are in the laboratory environment or are given off by products being handled and stored.    There are many recorded incidents of explosions, fire, and severe property damage due to vapors and gases being ignited within the storage units or in the lab itself that are caused by incorrectly specified or improperly used laboratory refrigerators and freezers.

What you Need to Know

Lab refrigerators and freezers used to store volatile substances or used in rooms where such substances are in the air must be specially designed to isolate any source of ignition from these substances.

Designed to strict specifications, flammable storage refrigerators and freezers such as Nor-Lake models offered by Tovatech must be used when volatile products are being stored.  Using sealed non-breakable containers is not an option.  Explosion-proof units, also available from Tovatech, must be specified when vapors in the laboratory could be ignited by a stray spark.  Conventional household or standard lab refrigerators and freezers cannot be safely modified to avoid a disaster.

Sources that can cause internal ignition of vapors include lighting, timer housings for defrosters, thermostats and compressors.  A spark-initiated explosion can blast off the door, scattering refrigerator or freezer parts and contents across the room with possibly fatal consequences to individuals unfortunate enough to be in the way.  That is why these units are constructed to isolate the contents from any source of internal ignition.

More costly explosion-proof units have stricter design requirements that separate internal and external environments.  Unlike the flammable units that can be plugged into a wall outlet, explosion-proof units are hard wired into the building’s electrical grid.

The Take-Away

Photographs and descriptions of laboratories wracked by explosions due to improperly used lab freezers or refrigerators provide ample support for insisting on flammable or explosion-proof units.   “Saving money” is a poor excuse when considering the hundreds if not thousands of dollars in cost and potential injury that can occur when improper units are used.

Deciding between explosion proof and flammable storage is easy.  If the explosive vapors are on the outside of the refrigerator choose explosion proof.  If they are only on the inside of the refrigerator choose flammable storage.  In any case you can count on the scientists at Tovatech for correct advice on specifying lab refrigerators and lab freezers that conform to regulations in your industry.

What experiences have you had, or know of, relating to explosions caused by lab refrigerators or lab freezers?

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