Intumescent paint is considered a passive fire protection system. It is named like that because it does not contribute to extinguish the fire, however it helps to reduce the damage, material and personal.
The intumescent paint has the property of expanding through chemical reactions, which are activated when the temperature increases. When this occurs, the intumescent paint becomes a thermal insulator, foamy texture and remains attached to the metal structure where it was applied.
The coating, when there is the presence of direct fire or extreme heat, is inflated and carbonized, therefore, a very thick layer of sponge slag is created and acts as an insulator, which delays the time in which a metal structure reaches its collapse temperature (538 ° C).
It is worth noting that many people confuse the intumescent with fire retardant paints. However, they are completely different because the later is used to protect flammable materials (eg wood), and is a film that isolates it from the fire and avoids emitting gases that contribute to the spread of fire. On the other hand, the intumescent paint is applied to heat conducting materials such as the steel and prevents to reach the collapse temperature.