Dust Explosions - Substances, Critical Temperatures and Concentrations

Critical temperatures and concentration parameters for substances like coal, zinc, uranium and more. Analyze dust explosion hazards based on ignition temperature, minimum explosive concentration, and relative explosion hazard levels.

SubstanceIgnition Temperature (°C)Min. Explosive Concentration (oz/ft³)Relative Explosion Hazard
Alfalfa460
Aluminum6500.045Severe
Al-Mg alloy0.02Severe
Cereal grass550
Chromium0.23Strong
Coal6100.055Strong
Copper900Fire
Corn400
Epoxy Resin5300.02Severe
Flax shive430
Grain dust (winter wheat, corn, oats)430
Iron4200.1Strong
Magnesium5200.02Severe
Rice440
Silicon0.11Strong
Soy flour540
Tin6300.19Moderate
Titanium4600.045Severe
Uranium (finely divided metal dust)200.06Severe
Wheat flour380
Wheat straw470
Zinc6000.48Moderate

Basic Rules for Dust Explosions

Basic rules to observe for dust to be capable of causing a dust explosion:

  1. The dust must be combustible - The substance must be capable of undergoing combustion
  2. The dust must be airborne - The particles must be suspended in air
  3. The dust must have a size distribution capable of flame propagation - Particle size affects combustibility
  4. The dust concentration must be within the explosive concentration range - Must be between lower and upper explosive limits
  5. An ignition source with high enough temperature must be present - Temperature must exceed the ignition temperature
  6. The atmosphere must contain sufficient oxygen to support and sustain combustion - Typically requires >8% oxygen

Key Parameters

  • Ignition Temperature of Dust Cloud (°C): The minimum temperature at which a dust cloud will spontaneously ignite
  • Minimum Explosive Concentration (oz/ft³): The lower explosive limit - the minimum dust concentration required for explosion
  • Relative Explosion Hazard: Classification of explosion severity (Fire < Moderate < Strong < Severe)
Calculator

Inputs

Results

Concentration-- g/m³
Concentration-- mg/cm³