Condensed aerosol fire suppression is a particle-based method of fire extinction. It is similar to but not identical to dry chemical fire extinction methods, using an innovative pyrogenic, condensed aerosol fire suppressant. It is a highly effective fire suppression method for class A, B, C, E and F (as is the case for most fire-extinguishing agents, it is not applicable to metal fires – class D). Some aerosol-generating compounds (e.g., potassium nitrate-based) produce a corrosive by-product that may damage electronic equipment, although later generations lower the effect.

Condensed aerosol fire suppression systems employ a fire-extinguishing agent consisting of very finely divided solid particles, suspended in an inert gas. Those superfine aerosol particles are pyrotechnically generated via the combustion of an aerosol-forming agent (AFA) which is stable at room temperature and does not need to be stored in a pressurized container.

Benefits include high performance (3 times more effective than banned Halon 1301, with the aerosol leveraging both cooling, dilution and chemical inhibition), general availability (from plant-size systems to compact and lightweight portable tooling), low toxicity, environmentally friendliness (e.g., 0% ozone depleting potential), non-pressurized systems, and overall cost-effectiveness.

That fire-extinguishing medium is not stored "as is" but rather produced "on demand": the aerosol microparticles and effluent gases are generated by an exothermic reaction initiated within a condensed, solid, aerosol-forming compound. Typically, a fuse ignites the aerosol-forming compound to generate hot aerosol colloids.

The hot aerosol fire suppression technology went through several generations: gen I (oil tank suppression system) and gen II (potassium nitrate-based, efficient but with corrosive byproducts) denoted as K-type systems, then gen III (boosted strontium salt-based, less deliquescent and generating less corrosive byproducts) denoted as S-type systems. All generations leverage alkaline or alkaline earth metal nitrates (which act as oxidants in the hot aerosol generating process), and different kinds of reductants.

Typically, in K-type systems, fire-extinguishing aerosol particulates consist of potassium carbonate (K₂CO₃) and potassium bicarbonate (KHCO₃) that are produced from the thermal decomposition of potassium nitrate (KNO₃) mixed with various reducers, binders (e.g., organic resin or melamine resin) and additives:

KNO₃ (solid) + C_nH_mN_pO_q (solid) = KHCO₃ (solid) + K₂CO₃ (solid) + CO₂ (gas) + N₂ (gas) + H₂O (gas)

with C_nH_mN_pO_q being a gas-generating oxidizer^{[citation needed]}