Energetic materials are liquid or solid materials with a high amount of available stored chemical energy. Common energetic materials include propellants, explosives, pyrotechnic (PEP) compositions, and other fuel / oxidizer mixtures. Energetic materials are characterized by their sensitivity (the ability to initiate a reaction from an energy stimulus) and reactivity (propagation and effect characteristics after ignition).

Ignition or initiation of an energetic material requires an energy stimulus. Forms of energy stimulus include impact, friction, electrostatic discharge (ESD) or electrical spark, shock and thermal / heating among others. Sources of energy stimulus include:

Pinching, cutting, grinding, or slicing

Sliding surfaces together

Drilling, hammering, welding

Static discharge, electrical spark, or mechanically produced spark (hand tools, power tools).

High explosives residue in a cut 4-inch processing pipe

Any tool, power device, or equipment has the potential to create an initiation event. “Non-sparking”, “spark-resistant” or “spark-proof” tools may not produce hot mechanical sparks, but may still initiate energetic materials by electrical spark, static discharge, being dropped (impact energy), or being dragged / rubbed (friction energy).

Reactivity levels define the type of event that can be expected once a material has been ignited or initiated. Reactivity levels of concern include burning, deflagration, and explosion / detonation.

Any lower level reaction (burn, deflagration) can escalate to a higher level (explosion / detonation) given the right conditions: