Explosive

An explosive is a substance or mixture that rapidly releases energy through a chemical reaction, producing high-pressure gases, heat, and often a shock wave. The energy release can occur by detonation, where a supersonic wave travels through the material, or by deflagration, a slower, heat-driven combustion. These two modes have different effects on surrounding materials and are chosen for different applications.

Explosives are often grouped by sensitivity and intended use. Primary explosives are highly sensitive and used to initiate larger charges, while secondary explosives are designed to be less sensitive and are the main energy sources in blasting and ordnance. They are also categorized by mechanism, with high explosives typically detonating and acting at high brisance, and low explosives deflagrating. Common classes include organic nitrates and nitro compounds, nitrate-based blasting agents, and specialized gel or plastic formulations.

Uses range from mining and construction blasting to demolition, rock fracturing, propellants, and shaped charges in military engineering. In controlled settings they are manufactured, handled, stored, transported, and disposed of under strict safety standards and regulatory regimes to minimize the risk of accidental initiation and environmental harm.

Historically, explosives played a central role in industrial development and warfare. The 19th and 20th centuries saw rapid advances, including the development of dynamite, TNT, RDX, and modern plastic-basted and slurry explosives. Ongoing research focuses on performance, safety, environmental impact, and regulatory compliance.