Small Fire on Bench

Updated May 27, 2014

Incident – Brief description


Graduate student was working late (11 PM) at night on a Sunday. The student was performing standard microbiological technique wearing appropriate PPE (gloves, safety glasses, flame resistant lab coat) inoculating a microorganism (RG1-BL1) on petri dishes containing culture media. The student was utilizing a sterile technique by means of a gas burner, 100% ethanol and a metal loop to inoculate cultures. According to the student statement, the “jar” containing ~30 mL of 100% ethanol somehow shattered producing a small fire that spread on the bench. The student reacted quickly turning off the gas source, removing materials (petri dishes) and reaching for the fire blanket which the student used to smothered the fire. Fire alarm was not triggered and the student turned on the emergency exhaust on the fume hoods closest to the bench to eliminate the smoke generated during the fire. The student was not injured.


Response action


The student was not alone in the lab at the time of the incident. The student used the fire blanket successfully to extinguished the fire and clean the area. The student notified the PI the next morning (PI was out of town) and then reported the incident to the DLC EHS coordinator who in turn reported to the EHS Office Lead Contact. Biosafety and Safety team members joined the EHS coordinator at the location to investigate further.


Immediate Cause– contributing cause(s)


Working late and probably tired on a repetitive task may have contributed to a process error in the technique.

“Jar” containing 100% ethanol was not tempered glass and perhaps was old therefore prone to cracks and therefore shatter more easily.



Causal factors (confirmed or suspected)


Working tired (late at night) on a repetitive task can produce fatigue and user error. We suspect the student switched the order of the procedure igniting the ethanol shattering the jar and spilling the flammable liquid on the bench.


Recommended corrective action(s) or lessons learned


It is known that fire blankets can be used to smother small, insipient fires under the right circumstances. After all, fire blankets use fire resistant fabrics designed to help smother fires on a person whose clothes have ignited. While fire blankets can be successful for small fires, they are not ideal and not recommended for this type of use by fire safety professionals. Fire blankets are primarily for smothering clothing fires and articles on a person that have ignited. Fire blankets are not designed to put out fires in fume hoods or bench tops. Not all fire blankets can be used to extinguish electrical fires. When used to extinguish heavy oil or chemical fires, these materials can sometimes seep through the blanket and reignite, causing the fire to spread. This has actually happened in several instances at MIT when researchers tried to use a fire blanket to put out flammable liquid fires. Blankets can lose their flame retardant features within 5 years. Fire blankets are only required in the event the laboratory works with flammable materials, but no emergency safety shower or drench hose is available. At present DoF (Department of Facilities) is not maintaining our existing fire blankets, nor replacing them if they are damaged or missing. Since new laboratory renovations or buildings have emergency safety showers, fire blankets are not being installed. As stated earlier, fire blankets should not be used to extinguish building or area fires. Fire blankets are primarily for smothering clothing and articles on a person that have ignited. While blankets are effective for people of fire, they also trap heat if wrapped in the blanket and can extend the burn that a person receives. The preferred method is an emergency safety shower if located nearby (within 5 feet). If not nearby, then the stop, drop and roll method should be used to extinguish the flames. If a fire blanket is available, it can be used on the victim to continue to smother the flames.


Working late and possibly tired is not a good idea when a long and repetitive task is performed.


Condition of glassware used to contain flammable liquids used in microbiological technique should be routinely monitored. Glassware should be temperate glass with a lid preferably. Flammable liquids, such as ethanol should be kept at a minimum at any time. Options such as the use of sterile individually wrapped disposable spreaders and loops or the use of an Infrared heat chamber to sterilize loops and spreaders with an Electric heat source eliminates would reduce the hazards from gas and open flames. 

Improve housekeeping on the bench where microbiological work is performed by reducing clutter on the bench and removing cardboard boxes and other containers thatcould be damaged or burned.

What worked well –


The lab follows established written protocols for Personal Protective Equipment and is compliant with policies.

The student reacted quickly in the correct order of priority to deal with the hazards at the moment of the incident.