Flammable antifreeze in fire sprinklers allegedly causes explosion

In August of 2009 in Truckee, CA, a man was cooking on a stove when the pan caught fire, activating the fire sprinklers. Upon activation of the sprinklers, a violent explosion occurred which resulted in 1 death and 4 burn injuries to the family.

I came across this copy of a report (from the IAFSS mailing list) which details a report of a cooking fire turned explosive when the sprinklers were activated. Allegedly the propylene glycol used in the fire sprinkler system as an antifreeze aided in the explosive event, and another case is cited in which the antifreeze ignited and assisted in growing the fire from its ignition source.

The report can be found here: California –explosion– report (PDF)

While I have taken a few courses in fire sprinkler systems, I am not extremely familiar with the flammability of antifreeze such as propylene glycol, but allegedly the atomization of the droplets causing the liquid to become flammable was the cause of this explosion. More flammability and MSDS hazard info is cited in the report.

The report presents many questions at the end which would be useful in quantifying the relationship of the antifreeze in this case, especially since (to my understanding) propylene glycol is the most widely used antifreeze in sprinkler systems. I look forward to finding out more about this topic, and I think it’d be a great research project for a student or research firm to take on.