Which list correctly identifies the five sides of the dust explosion pentagon?

Which list correctly identifies the five sides of the dust explosion pentagon?

• A. Temperature, pressure, humidity, particle size, mixing
• B. Viscosity, density, surface area, solubility, volatility
• C. Reactivity, moisture, pH, color, shape
• D. Fuel (dust), oxidizer (air), ignition source, confinement and dispersion (of dust)

Answer: (D)

The five sides needed for a dust explosion are the combustible dust (fuel), the surrounding air (oxidizer), an ignition source, confinement to allow pressure to build, and dispersion of the dust into a cloud. This combination is what lets a dust explosion occur: you need fuel and oxidizer present together, a source of energy to ignite, a space that can trap pressure, and enough dust dispersed in that space to form a combustible mixture. The set that lists fuel (dust), oxidizer (air), ignition source, confinement, and dispersion matches these essential elements, so it is the correct one. Other options mention factors like temperature, humidity, viscosity, or color, which can influence ignition tendencies or flame behavior but do not constitute the five required sides of the pentagon.

The five sides needed for a dust explosion are the combustible dust (fuel), the surrounding air (oxidizer), an ignition source, confinement to allow pressure to build, and dispersion of the dust into a cloud. This combination is what lets a dust explosion occur: you need fuel and oxidizer present together, a source of energy to ignite, a space that can trap pressure, and enough dust dispersed in that space to form a combustible mixture.

The set that lists fuel (dust), oxidizer (air), ignition source, confinement, and dispersion matches these essential elements, so it is the correct one. Other options mention factors like temperature, humidity, viscosity, or color, which can influence ignition tendencies or flame behavior but do not constitute the five required sides of the pentagon.