Flammability is a material’s tendency to ignite and continue burning when exposed to heat or flame. It depends on the material itself, additives such as flame retardants, and the part’s shape, thickness, and surface area. A highly flammable plastic may soften, drip, or sustain combustion quickly, while a lower-flammability material may self-extinguish or resist ignition longer.
In cyber security, flammability matters because many systems are physical: routers, sensors, batteries, cables, and 3D-printed enclosures can be exposed to heat from overloaded components, sparks, or deliberate fire. Attackers may use heat to destroy evidence or disable devices, while defenders reduce risk by choosing fire-rated materials, separating hot components, and testing hardware for thermal and flame exposure. For printed parts, flammability testing helps confirm that a design is safe for its real operating environment, not just its shape and fit.