Hood Fire Involving Unattended Operation with Hexane Near Hot Plate


A fire erupted inside a hood containing two reactions running unattended. A laboratory worker had placed nitrobenzene inside an oil bath atop a hot plate. The hot plate had been operating for three days, heating the oil bath to 200° C. A plastic squeeze bottle of hexane was placed next to the hot plate. Eventually, the squeeze bottle warmed enough to pressurize the container, forcing liquid hexane out of the bottle and onto the hot plate, where it ignited. Another laboratory noticed the smoke and attempted to put out the fire using a dry chemical extinguisher. A maintenance worker also noticed the fire and assisted the laboratory worker. Their attempts were not successful.  

The fire department was dispatched. Since the Emergency Information Poster on the door to the laboratory was inaccurate and there was a significant language barrier between the laboratory worker and the fire department personnel, a hazmat response team was dispatched. Three buildings were evacuated for more than three hours. The laboratory worker and the maintenance worker were showered and scrubbed by the hazmat team and their clothing was confiscated (it was later washed and returned to them). While this was probably an overreaction by the emergency response personnel, it illustrates the implications of not having an accurate, up-to-date emergency information poster.  

Containers of volatile liquids placed near heat sources can become pressurized.   Materials not involved in an experiment should be removed, as possible, to avoid having them become involved in a fire or other incident.  Keeping the Emergency Information Poster up-to-date helps to ensure a proportionate response by emergency response personnel.  Evaluate the potential problems related to experiments left unattended for days at a time.