Fine dust of many substances when suspended in air may cause explosion called as dust explosion. This may occur during production, transportation, or storage.

“Combustible dusts often originate from organic or metal solid materials that are ground into very small particles, fibers, fines, chips, chunks, flakes (or a small mixture of these), which present a fire or deflagration (sudden and rapid combustion) hazard when suspended in air or some other oxidizing medium over a range of concentrations. If the burning is confined by an enclosure such as a building, room, vessel, or processing equipment, then the resulting pressure rise may cause an explosion.”

Building a Safety Program to Protect the Nanotechnology Workforce: A Guide for Small to Medium-Sized Enterprises| Centers for Disease Control and Prevention National Institute for Occupational Safety and Health

Which dusts may cause explosion?

According to OSHA’s Combustible Dust in Industry: Preventing and Mitigating the Effects of Fire and Explosions), any “material that will burn in air” in a solid form can be explosive when in a finely divided form which can result in dust explosion.

Example:  Dust from coal, cocoa, coffee, flour, grain, pollen, powdered milk, sawdust, starch, sugar, powdered metals etc..

Five elements of dust explosion

• Fuel
• Confinement
• Dispersion
• Oxygen
• Ignition

How dust explosion occur?

Organic and metal solids may generate dust which when suspended in air with right temperature and confinement results in dust explosion triggered by hot surfaces, fires, machineries, friction or electrostatic discharge.

One of the recent dust explosions widely reported in news was 2015 Taipei Water Park Fire (Formosa Fun Coast).  Organizers dispersed coloured corn starch powder as part of the entertainment activities. This somehow resulted in sudden deflagration resulting in 496 injuries and 15 deaths.

What does IMDG Code says about dust explosion?

IMDG Code identifies dust of sulphur and xanthates to have properties for forming an explosive mixture with air which may be ignited by static electricity. This property may be applicable to any other solid dangerous goods in powdered form or solids which may generate powder due to transport conditions.

Measures must be taken to prevent dangerous electrostatic discharge during transport, loading or unloading for bulk containers and IBCs carrying powdered solids or solids which may generate powders during transport.

Watch “Inferno: Dust Explosion at Imperial Sugar”