IG-55, marketed as Argonite, is an inert gas fire suppression agent made from a 50/50 blend of argon and nitrogen. Both are natural atmospheric gases, giving IG-55 zero ozone depletion potential, zero global warming potential and no atmospheric lifetime concerns. It extinguishes fire cleanly by lowering oxygen, leaving no residue and no risk to electronics, which makes it a popular choice for data centres, server rooms and electrical switchrooms. MEP designs, supplies and installs IG-55 systems across the UK.
IG-55 is composed of 50 percent argon and 50 percent nitrogen. On discharge it reduces the oxygen concentration in the protected room from around 21 percent to roughly 12 percent, enough to suppress the fire while remaining safe for occupants. The balanced blend gives IG-55 a density so it mixes evenly and stays suspended in the room, maintaining an effective concentration throughout the required hold time without settling or stratifying.
Because it is clean, non-conductive and environmentally benign, IG-55 suits any space where oxygen reduction is acceptable and water would cause damage: data centres, comms rooms, control rooms, UPS and battery rooms, and archives. The gas is stored in high-pressure cylinders remote from the risk, so it needs plant space but keeps the protected room clear. We size the cylinder bank, pipework and pressure relief venting to suit your enclosure and confirm performance with room integrity testing.
Get in touch with our team of fire suppression experts to discuss your requirements and receive a tailored solution.
IG-55 is an inert gas fire suppression agent made of 50 percent argon and 50 percent nitrogen. Argonite is the common trade name. It extinguishes fire by reducing oxygen and leaves no residue.
Exactly half argon and half nitrogen (50/50 by volume), two naturally occurring atmospheric gases, which is why IG-55 has no environmental impact.
Yes, when designed to BS EN 15004. It lowers oxygen to a level that suppresses fire but remains breathable limited periods of exposure.
IG-55 is argon and nitrogen only, whereas IG-541 (Inergen) adds around 8 percent CO2. Both perform similarly; the choice usually comes down to cylinder count, cost and enclosure design.
No. It is an electrically non-conductive gas that leaves no residue, so it is safe for servers, switchgear and other sensitive equipment.
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