Combustibe Dust Fires and Explosions
Through his involvement with a commercial property insurance carrier, Ben Peetz sees a wide variety of properties across a large region of the United States. A firefighter with the Napoleon (IN) Volunteer Fire Department, Peetz noted one recurring theme is the local fire department’s lack of familiarity with a manufacturing facility’s operations. Most of the recent global attention to combustible dust fires and explosions has been on the managers and workers within these facilities. His Wednesday morning classroom session, “Combustible Dust Fires and Explosions,” gave attendees a basic understanding of combustible dust operations and the associated dangers, while also reviewing safe mitigation practices and potential problems that can arise in responding to a combustible dust operation.
Combustible dusts are derived from many sources—grains, wood, metals, plastics—in operations that handle and process these materials. The best way to address a combustible dust fire or explosion situation is prevention, primarily in the form of proper housekeeping and equipment maintenance. A dust layer of 1/32 inch over 5 percent of the surface area is the threshold for an Occupational Safety and Health Administration citation.
Explosions involving combustible dusts occur when the three elements of the fire triangle (fuel, ignition source, oxygen) meet the two additional elements of the dust explosion pentagon, the suspension of dust and the compartmentalization of the fire. Dust explosions are not a new phenomenom. The first recorded dust explosion occurred in 1785 at a flour mill in Italy.
Firefighters should never, ever climb a burning dust collection unit or storage structure, because of the extreme risk of an explosion or massive flash fire.
Peetz is the author of “Combustible Dust Fires and Explosions,” which appeared the March 2012 issue of Fire Engineering.