Due to the reactivity between a flammable metal fire and water, AVD is applied in the form of a "mist" or a "foam". The Vermiculite particles within the mist or foam are deposited on the surface of the burning fuel to create a film over the top of the fire. This film instantly dries and because the high aspect ratio platelet particles overlap and bind together, they produce a non flammable oxygen barrier between the fire and the atmosphere.
This process offers cooling to the surface of the fire and as the AVD platelets begin to build up layer upon layer of vermiculite particles on the top of the fuel source, the fire is gradually cooled and brought under control. Unlike other Class D Extinguishing Agents where the fire has to be left for long periods of time before the fire is truly under control and completely burnt out, AVD offers rapid control of the fire.