Fire Triangle

Fire Triangle

Dust Explosion Pentagon
Dust Explosion Pentagon

Not all dust is combustible. Dust will vary in the potential for combustion and how severe airborne dust deflagrations might be. However, materials which can burn or corrode in contact with oxygen can form combustible dusts. These reactive materials include:

Metals Grains
Plastics Wood
Coal Paper
And other carbonaceous materials

And other organic compounds:

• additives
• Solid food products
• Pharmaceuticals

For a dust deflagration to occur, a large and dense cloud of dust needs to become airborne at one time and make contact with an energy source that is strong enough to cause ignition. To understand how dense a dust cloud is and what type of energy sources are required to create an ignition hazard can only be learned through specialized lab testing.

For certain dust, a static spark is enough to ignite a dense cloud vs. others that may require an open flame or contact with a hot surface. A small explosion or shock can stir up settled dust into the air creating a big cloud that is often ignited by the heat of the first explosion. It's important to note that finer dust particles become airborne and ignite more easily.

Preventing Combustible Dust Hazards

• Understand the materials that may be present in your working environment and find out what they are if you are not sure.

• Never use compressed air for cleaning powdered materials and dust.
• Welding or other hot work processes should never take place where combustible dust are present on surfaces or where they might become airborne. Check adjacent and concealed spaces for dust. Consult a supervisor or safety professional if you are unsure about the risks or safety requirements.
• Implement wet downdraft tables or central dust collectors in your industrial facility to establish employee safety. To determine what explosive dust collection system is best for your application, get in touch with us.
• Never work on equipment that handles or collects combustible dust unless you are authorized to do so and have had the required training.
• Always be extra careful about electrical safety, including static charge buildup.
• Follow all safety precautions, hot work procedures, and any other steps designed to prevent dust explosions.

Resource: Combustible Dust Hazards in The Welding and Cutting Environment