A fire occurred in a dust filter of a secondary pharmaceutical powder-transfer operation. No personnel were injured. Damage to property was largely superficial confined to inside contamination of the equipment with powder, soot, and other products of incomplete combustion. The root cause of the incident can be traced back to the selection of an unsuitable filter not capable of handling low-MIE powders more than 15 years ago. (c) 2012 American Institute of Chemical Engineers Process Saf Prog, 2012