Hello Everyone,

I wanted to share with you a recent near miss that took place in our school at early hours on Thursday, April 6, 2017. The near miss is about a runaway furnace/heating block that was luckily discovered before causing extensive damage to equipment, or even worse – a fire. Please see below the details:

Date and time: Thursday, April 6, 2017, 1 am (time of discovery)

Location: FRNY building, 3^rd floor, new wing.

Description of near miss:

                At 1:00 AM  a graduate student went to the 3^rd floor, new wing of FRNY, and felt the smell of  burning plastic.  The smell got stronger as he approached FRNY 3182, and he noticed a faint haze in the room.  A feedback system was used to control the temperature of a heating block; a thermocouple inserted into the heating block measures and sends the heating block temperature to the controller, which in turn heats/cools the heating block until the thermocouple reads the set temperature.

The heating block was placed on the plastic cover of an instrument and the thermocouple was removed, thus not in contact with the heating block.  The set point was set to 24C, but FRNY’s building temperature decreased to 23C that night.  As a result, the feedback system tried to increase the heating block temperature from 23 to 24C, but the thermocouple (not in contact with the heating block) continued to read a temperature of 23C, so the heating block continued heating to the point where it was burning the plastic.

Immediate action taken: The researcher and another person present at the scene,  entered the lab wearing lab coats and face masks. They turned off the power to the heating block and the removed the heating block from the plastic lid. Due to the lack of safety shut-down procedures for this unit, the researcher in charge with this experiment was contacted via cell phone at ~1:30 AM for shutdown procedures, and power to the FTIR was turned off by physically unplugging the power cord. The PI was informed of the incident via email shortly after that. The room was deemed off limits and allowed to ventilate for 6+ hours. 

Cause of incident and actions taken: There were a few deficiencies identified, that led to this near miss:

· There was no written SOP for operating the unit

· There was no over-temperature protection with a permanent thermocouple attached to the heating block to shut off power completely. 

· After inspecting the unit closer, an electrical hazard was identified – short power cable that led to frayed wires, near conducting block.

The incident was investigated and discussed in a group safety meeting, and the following action items will be implemented to prevent similar situations:

· Over-temperature controllers, with a permanently (bolted/screwed) attached thermocouple (that will cut power to the heater if the unit temperature is greater than the set temperature) will be installed on all experimental setups that operate at adjustable temperatures.

· All heating blocks in the lab will be inspected, and temperature safety shut off valves will be installed, where not present.

· All heating blocks have to be unplugged when not in use, to avoid electrical shock (since it is difficult to ground heating blocks)

· All tubing and equipment has to be permanently grounded to overhead tray.

Fortunately the incident was noticed at before developing into a fire, or producing extensive damage to the instrument the thermocouple was placed on, and to the lab.

I hope that sharing with you the details of this near miss, including the actions taken to correct identified deficiencies, will prevent similar situations from developing in your labs.  

Thank you for your commitment to safety!

Gabriela

On behalf of the ChE Safety Committee

__________________

Gabriela Nagy, PhD

Industrial Education Director

ChE Safety Committee Chair

Davidson School of Chemical Engineering

Room FRNY G041D

Purdue University

Tel: (765)-496-1710

E-mail: nagyg@purdue.edu