At approximately 9:30 AM the Birck Nanotechnology Center was evacuated due to a toxic gas alarm. The building was determined safe to reenter prior to 10:30 AM and the all-clear was given by Purdue Fire Department. The alarm was caused by a liquid residue that formed during the dichlorosilane purging process that tripped the toxic gas alarm. Condensation of the warm gases in the colder exhaust ductwork was determined to be the root cause of the incident. The dichlorosilane was confined to the gas cabinet and exhaust ductwork proximal to the gas cabinet, and at no time were any building occupants in danger. A new software upgrade that would have precluded this triggering an evacuation was delayed by the supplier due to the Christmas holidays. They are working to rapidly complete this modification to our system. Additionally, members of the Engineering Staff have modified the purging process for dichlorosilane. This new procedure will be implemented immediately. Engineering Staff members are also working to modify the piping in the system to prevent the discharge of liquids into the exhaust ductwork during purge cycles. This work will be completed as soon as practical. Thank you for your understanding and cooperation during this emergency situation. John Weaver John R. Weaver Facility Manager Birck Nanotechnology Center Purdue University (765) 494-5494 jrweaver@purdue.edu
