[Che-student-staff-list] Safety Update: Follow-up to 11/7 Fire and Evacuation in Chemical Engineering

[Davis, Linda S]

ChE Faculty, Staff and Students,

On November 7, 2011, Forney was evacuated due to a laboratory fire.  ChE personnel responded appropriately to the fire alarm by evacuating and remaining in the vicinity of Forney.  The Purdue fire department responded to the alarm, extinguished the fire and gave the all clear after approximately 45 minutes.  The fire occurred in a research laboratory trash can and was extinguished with damage only to the trash can.  Although we never want to have an emergency, the response by ChE personnel to the fire and alarm was very good.

We can all learn from this incident.  The following is a description of the work that was underway, the apparent cause of the fire and future precautions that will be taken in the laboratory.

Molybdenum carbide (Mo2C) was being prepared in a series of reactors.  Since Mo2C reacts vigorously when exposed to air (pyrophoric), the procedure is to passivate the material before removing it from the reactors.  (Passivation involves exposing the material to a mixture of air/argon in which the concentration of oxygen is ~1.5%.)  Following passivation the material was removed from the reactors and collected in a sample vial using weighing paper.  The used weighing paper was thrown away in the trash can.  Soon, flames were observed the trash can and the trash was burning.  It appeared that the fire started when the weighing paper was thrown in the trash.  There may have been a few particles of Mo2C that were stuck to the paper and not fully passivated.  The unpassivated Mo2C particles reacted with oxygen in the air and caught fire.  In the future, weighing papers (or other flammable materials) will not be used to transfer Mo2C.  A metal plate will be used.  Additionally, passivation will be done in stages where the oxygen concentration is gradually increased from 1.5 to 20%.

Please review this incident in your research groups, particularly if you work with pyrophoric materials.

Thank you.

Regards,
Linda

Linda S. Davis
Industrial Education Director
Chair, ChE Safety Committee (https://engineering.purdue.edu/ChE/AboutUs/Safety.html)
School of Chemical Engineering
Purdue University
lsdavis at purdue.edu<mailto:lsdavis at purdue.edu>
(765)496-1710

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