With the worldwide ban on Halon 1211, the race was on to create a clean, safe alternative for use in highly sensitive areas. As a result, the US manufacturing giant DuPont created FE-36, or Hydrofluorocarbon-236fa (HFC-236fa).
FE-36 works almost as effectively as the illegal halon, is less toxic, and does not deplete the ozone layer. FE-36 also leaves no residue, is non-corrosive, non-conductive, and will not cause thermal shock damage to machinery.
How Fire Extinguishers Containing DuPont FE-36 Work
These extinguishers discharge a stream of gas and liquid droplets that are propelled into the heart of the fire, stopping combustion through a chemical reaction and by absorbing the fire’s heat.
Since FE-36 becomes a gas at -1.4 degrees C (39 degrees F), it leaves no residue behind and after the fire, dissipates into the atmosphere. FE-36(tm) fire extinguishers can be used on fire classes A and B, and directly on electrical equipment.
FE-36 Fire Extinguishers in Europe
Although not yet widely available in the UK and Europe, these extinguishers are used in medical facilities across the USA. In addition, portable fire extinguishers containing FE-36 can be used in sensitive locations such as computer rooms, document stores, clean rooms, telecommunications facilities, control rooms, switch rooms, marine craft and installations, banks, museums, archives, laboratories, and airplanes.
The most common range of fire extinguishers containing FE-36 are Cleanguard extinguishers from Ansul.
In the UK Today
Motorsport participants might also be interested in the Zero 360, an FE-36 extinguisher especially for high performance racing and rally cars from Lifeline.
Also seen in small automatic extinguishers, the defunct Firemaster company’s previous management have set up a new company called Fireblitz Extinguisher and are now supplying 1kg and 2kg automatic sizes again.
“Total Flood” Fire Suppressant Systems
DuPont FE-36 can now be used to replace Halon 1301 in fixed fire protection systems. Fire extinguisher systems with FE-36 come into their own where a ‘total flood’ fire suppressant system is required. This involves ‘flooding’ an entire room or enclosed area with sufficient fire fighting agent to extinguish the fire. (If CO2 gas were used instead, the volumes involved would prove fatal to anyone in the area.)
FE-36 and Hydrogen Fluoride
When combusted, under certain conditions, FE-36 can produce hydrogen fluoride (HF). Whilst this gas is generally produced in small quantities, and the gas itself boils just below room temperature, you should make sure that after a fire, the area is fully ventilated before staff return.
You should also avoid breathing in any fumes from an FE-36 extinguisher treated fire, as on contact with moisture, including human tissue, hydrogen fluoride converts to hydrofluoric acid. This acid is highly toxic and corrosive.