Lab explosion due to domestic fridge
USA: A fridge explosion at Michigan State University (MSU) may have been due to the use of a domestic fridge in a laboratory environment.
Emergency services attended MSU on Friday after an explosion in a laboratory in the University’s Giltner Hall. Part of the building was evacuated following the incident and, fortunately, the laboratory was empty at the time and no one was injured.
The force of the explosion was said to have been large enough to blow off the refrigerator door and break windows more than 20 feet away.
The University’s own news service confirmed the explosion, explaining: “The explosion was caused by isopentane in one room where an apparent chemical reaction occurred in a refrigeration unit. Isopentane (2-methylbutane) was placed in an unsealed container in a typical household refrigerator. A spark caused an explosion of the flammable vapour.”
Isopentane is described as an extremely volatile and extremely flammable liquid.
It is unsafe to store flammable liquids in normal domestic refrigerators due to the number of potential ignition sources inside the compartment. These can spark a flammable vapour if it reaches its LFL. A number of explosions, injuries, and costly laboratory damage has resulted from using domestic refrigerators in a laboratory environment.
Under National Fire Protection Agency codes and OSHA Standards, only explosion-proof, spark-free or “desparked” fridges are deemed suitable for use in laboratories. All the electrical components in this type of refrigerator are outside the refrigerator, and the compressor is sealed or located at the top of the unit.
The Cooling Post is awaiting confirmation from the University as to whether its use of a typical domestic fridge was the actual cause of the explosion and/or whether the University is aware of these codes.
Domestic refrigerator explosions
Similar explosions with similar consequences have also occurred in homes across Europe and the Far East where domestic fridges now use flammable isobutane as the refrigerant. In these incidents, explosions have occurred if, due to a fault in the refrigerator, the flammable refrigerant has been able to leak into the refrigerator compartment.