Why Use Fluorocarbons? There are many reason for today’s success of Fluorocarbons as extinguishing agents, drawing parallels with yesterdays success of Halons.   The fact that Fluorocarbons can be pressurised with nitrogen, therefore allowing the system to be discharged within ten seconds, is a clear advantage over all other fire protection technologies which require discharge times up to ten times longer.In a real fire scenario, damages are more than proportional to the extinguishing time and therefore a fluorocarbon extinguishing system will dramatically decrease financial losses and any danger to human beings. Fluorocarbons are in general more effective agents than other solutions such as Inert Gases and Carbon Dioxide. Unlike Inert Gases Halocarbons do not extinguish the flame by lowering the oxygen level below that necessary to sustain the combustion, but by a combination of chemical and physical action. This results in lower extinguishing concentration which are well below those required by Inert Gases and therefore does not significantly change the levels of residual oxygen.   From a toxicological point of view the discharge of an Inert Gases system will result in a very low level of oxygen which can be very close to those allowed by humans by safety regulations. Therefore the calculation of the net protected volume is critical and any error could be very dangerous because this may cause an environment dangerous for human beings. The same does not apply to Fluorocarbons which present far lower risk to humans.   When assessing the safety it must be taken into account that very little is published on testing in a real fire scenario when the oxygen is also depleted by the fire itself. This makes the prediction of oxygen levels less reliable when fires are extinguished by Inert Gases.   Fluorocarbons systems are more compact, economic and simple to maintain. More over they occupies less space and require a number of cylinders that is up to ten times less than inert gases. This factor is most important in many applications (maritime applications, off-shore platforms, etc.) where space and weight are key factors. In addition Inert Gases require cylinders pressurized up to 200 bars compared to 24/42 bars of Fluorocarbons thus displaying a lower degree of safety.   Also Carbon Dioxide Systems have been proposed as substitutes for halon. However besides all of the above, the automatic discharge of CO2 is not allowed in normally occupied areas, since CO2 is lethal at very low concentration. Regulations require the complete evacuation of personnel from the protected area prior to system actuation. On the contrary Fluorocarbons allow the presence of personnel during the discharge of the systems. Moreover Carbon Dioxide, due to its low temperatures can produce thermal shock damaging electronic equipments.