Fire Extinguishers: If You Pull the Pin, Call It In! by Harry Oster and Brian Anderson

It has come to the attention of Fire Safety that sometimes fire extinguishers have been used to extinguish small fires and then placed back on their hook for re-use if another fire occurs.  Fire extinguishers are designed for a single use only.  Even if the pin is only pulled and the extinguisher is not discharged, report to EH&S office so the extinguisher can be replaced immediately.
Fire extinguishers are pressurized cylinders; any activation by squeezing the handle releases some.  Subsequent squeezes will never be as effective in terms of dispersal force and quantity of extinguishing material released. Consider a bottle of soda: you open the bottle, drink a glass, and replace the cap.  Is there any guarantee that if the bottle remains untouched for 6 months it will still be carbonated when opened again? Similarly, there is no guarantee that an extinguisher will work if it has been previously used. 
 All extinguishers are inspected monthly  to confirm that they are sufficiently charged, that the locking pin apparatus is intact, or if there is any indication of previous use.  In any of these instances, the extinguisher is placed out of service and replaced.
 There are a few things you can monitor to make sure the fire extinguisher is ready if you need it:

  • The path to the extinguisher is unobstructed; the extinguisher must never be used as a door stop.
  • Pressure is at the recommended level; the gauge reads in the green zone. 
  • The pin and plastic tamper seal/retainer are intact. 
  • The nozzle/parts are clear and free of chemical contamination.
  • The date on the service tag is not exceeded. 
  • Extinguishers should be wall mounted in a clear location and only removed for emergency purposes.

Please remember that Columbia University Policy requires that all fires, no matter how small, be reported immediately to:   Morningside Public Safety@ 212-854-5555 and Fire Safety@ 212-854-6670/ 6676
Medical Center Public Safety@ 212-305-8100 and Fire Safety @ 212-305-6780/8713

Oil Bath Incident by Juliet Ogbonnaya

Recently, a fire occurred in a chemical fume hood while a laboratory worker was heating an oil bath on a hot plate. Fortunately, no one was injured and the fire was quickly extinguished by personnel using the lab’s fire extinguisher.
It was the researcher’s first use of this particular hot plate and the oil bath.  The oil bath was not labeled as to its contents and had been prepared previously by someone no longer employed by the laboratory. With the temperature at 150 °C, the laboratory worker stepped away from the equipment to attend to another operation. Shortly after, a noise was heard coming from the hood as the bath ignited; the mercury thermometer used to monitor the temperature of the bath broke, releasing mercury in the hood. 
 While EH&S provided clean-up assistance and conducted an investigation, the exact cause of fire could not be determined.  Several recommendations for ensuring safe operation for this common procedure were provided: 

  • Label oil baths with the type of oil they contain and the safe working temperature of the oil.  Oil heated to temperatures above its flash point will smoke and possibly ignite. Silicone oil is recommended for higher temperatures and is a safer  substitute for other oils. Always refer to an MSDS for information on flashpoints.
  • Oil baths must be mixed well to ensure that there are no “hot spots” on the heating elements. This can be achieved by  placing the thermo-regulator close to the heater.
  • All active laboratory operations must be monitored closely and  never be left unattended.  If multiple operations are taking place, equipment should be outfitted with an automatic shut-off (e.g., thermal sensing device) or the watchful eye of  co-workers should be employed. 
  • Laboratory equipment must be periodically inspected/tested in accordance with manufacturer’s recommendation or industry standards- Never use equipment that may not be functioning properly.

Mercury is a toxic metal.   EH&S strongly encourages you to exchange your intact mercury thermometers for non-mercury  thermometers at no cost. If you must use a mercury thermometer, you must outfit your laboratory with a mercury spill kit. 
Contact EH&S for details.  

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