Ignition Sources of Dust Explosions

OSHA reports that more than 3,500 combustible dust explosions have occurred over the last 28 years. In 280 major incidents, over 700 injuries and 119 deaths occurred.

Dust explosions occurs when a sufficient amount of dust particles (fuel) disperse in the air (oxygen) and become exposed to a certain temperature (heat) in a confide space. According to OSHA, these five factors (oxygen, heat, fuel, dispersion and confinement) are knows as the “Dust Explosion Pentagon.” All elements must be present for a combustible dust explosion to occur.


Heat is also defined as the ignition source of dust explosions.  While fire seems the most obvious cause of dust explosions, fires only account for 8% of explosions. OSHA lists the percentages of ignition sources from dust explosions over the last 28 years.

  1. Mechanical Spark: A fiery particle produced when two hard metal surfaces strike together.
  2. Unknown: The second leading cause of combustible dust explosions are unknown because of the amount of damage caused by the explosion makes it impossible to find the cause of the ignition.
  3. Friction: The resistance triggered when one object or surface rubs against another.
  4. Static Electricity: A stationary electric charge, usually produced by friction, which results in sparks.
  5. Smolder Spot: A surface area that produces a slow burn without a flame.
  6. Fire: A burning or combustion when substances chemically combine with oxygen to generate light, heat and smoke.
  7. Hot Surfaces: A surface with a high temperature.
  8. Self-Ignition: A particle under high compression that ignites without a flame or spark; also known as spontaneous combustion.
  9. Welding: The action of fusing two metal pieces or objects together using extreme heat (i.e. blowtorch, electric arc, etc.).
  10. Electrical Equipment: The components of electrical distribution systems (i.e. distribution boards, circuit breakers, disconnects, etc.).

To find out how your company can prevent a combustible dust explosion, contact Carolina Filters. Our industrial experts will advise the best method of explosive dust removal.

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