3 Phases of a Dust Explosion
Did you know, between 2008 and 2012, the Chemical Safety Board documented 50 examples of combustible dust accidents? Each one occurred in a manufacturing or processing facility that ignored obvious risks. Ignoring this preventable hazard resulted in 29 fatalities and over 150 injuries.
What is Combustible Dust?
Combustible dust is made of fine particulates generated from metal, grain, agricultural, chemical, plastic, paper, carbonaceous products, and more. Manufacturing and production facilities’ equipment and machinery often sift, cut, mill, grind, or crush bulk products that generate these dusts.
The dusts can accumulate on all equipment and within hidden facility structures. This hidden dust, if not removed, can be the critical difference between a small fire and a facility-wide explosion. In the accidents reported by the Chemical Safety Board, most of the injuries and fatalities occurred because of this hidden dust the resulting secondary explosion.
Combustible dust explosions often occur in three phases. Keep in mind, however, that these three phases can be seconds (or less) apart.
Phase 1: Primary Explosion
The five elements of the Combustible Dust Formula (fuel, oxygen, ignition, confined space, and dispersed particles) combine to trigger an explosion inside equipment or in a confined area where dust has accumulated (false ceilings, dust collectors, below conveyor belts, etc.). This explosion can damage equipment and injure nearby employees.
Phase 2: Disturbance and Dust Cloud
Like an earthquake, the energy from the primary explosion can shake nearby rooms, attached equipment, or the entire facility. If the facility hasn’t been cleaned consistently with the correct tools, this disturbance can dislodge hidden dust, send it into the air, and form a dust cloud above unsuspecting employees.
Phase 3: Secondary Explosion
If the dust cloud meets any ignition source, it can explode with extreme force. (Ignition can be heat or flame from the primary explosion, or static electricity or friction within the facility). This fireball, or secondary explosion, will be significantly more destructive, risking the lives of all employees as it tears through a facility.
How Cleaning Can Save Lives
Combustible dust explosions are preventable with regular cleaning and a dedication to a proper maintenance schedule. In fact, proper cleaning could have specifically:
- Prevented the primary explosion
- Kept the primary explosion contained
- Eliminated the possibility of a dust cloud
- Saved employees from a potentially life-threatening secondary explosion
Are you making proactive decisions? It might be time for your facility to assess its cleaning practices.