Which term describes a finely powdered substance that can cause an explosion when mixed with air?

The term that describes a finely powdered substance capable of causing an explosion when mixed with air is dust. Dust refers to small particles that can become airborne and create a potentially explosive atmosphere when they are dispersed in sufficient concentration and mixed with air. This phenomenon is particularly relevant in industrial settings where materials such as flour, wood, or certain metals can create dust clouds that ignite and lead to a dust deflagration or explosion if an ignition source is present.

Grain typically refers to the whole seeds or kernels of cereal crops, which can also pose hazards, but it is not specifically about the finely powdered state. Powder refers more generally to any finely ground material without the specific emphasis on the explosive potential when mixed with air. Granule denotes small, grain-like pieces of a substance and does not necessarily imply the fine powder needed to cause an explosion. Dust, in contrast, is the term that encompasses the potential explosive behavior when fine particles are suspended in an air environment.