Fire protection
A clean-agent system floods a closed room with a gas that puts out a fire without water, without residue and without conducting electricity. In data centres and UPS rooms it comes in two families: halocarbon agents such as HFC-227ea (sold as FM-200) and FK-5-1-12, and inert gases such as IG-541 and IG-55.
It is a fixed system of cylinders, pipes and nozzles that fills a closed room with an extinguishing gas when a fire is detected. The agent is electrically non-conductive and leaves no post-fire residue, which is why it is used where water or powder would do more damage than a small fire. Honeywell's manual sums up the use: hazards where an electrically non-conductive agent is required, where agent clean-up creates a problem, where low weight matters, and where the room is normally occupied.
It is a total flooding system: it works only if the room holds the gas long enough. That is why room integrity, the doors, the dampers and the HVAC shutdown are part of every design, and why the inspection schedule checks the room as well as the cylinders.
| Halocarbon agents (HFC-227ea, FK-5-1-12) | Inert gases (IG-541, IG-55) | |
|---|---|---|
| How the fire goes out | A small concentration of agent in the room air | Oxygen is lowered below the level that supports combustion |
| Discharge time | Seconds: 6-10 for Honeywell's FK-5-1-12 systems | 60-120 seconds for Honeywell's IG-541 systems |
| Storage | FK-5-1-12: stored as a liquid, with nitrogen added as a propellant | IG-541: stored as a gas, at 200 or 300 bar |
| Breakdown in a fire | Decomposition products possible | None, according to Honeywell |
The table compares the two families as described in the manufacturer manuals cited here; a system designer settles the agent for a given room. Both families are listed for normally occupied rooms, and both rely on the same discipline: a pre-discharge alarm, a delay that lets people leave, and a room that stays closed until the fire is out.
By diluting the oxygen. Johnson Controls' data sheet gives the numbers for IG-541 (sold as INERGEN): a normal room holds about 21% oxygen, most ordinary combustibles will not burn below 15%, and the agent brings the room to about 12.5% oxygen while raising carbon dioxide to about 3%. The blend is 52% nitrogen, 40% argon and 8% carbon dioxide, and the carbon dioxide is there on purpose: Johnson Controls states that the mixture still allows a person to breathe in the reduced-oxygen atmosphere. IG-55, sold as Argonite, is another inert gas on the US EPA's list of acceptable agents.
Because an inert gas is discharged in large volume, the room needs a pressure relief design. Honeywell's manual warns that discharging any gaseous agent into an enclosure changes the pressure within it.
They are the two halocarbon clean agents most often found in data centre and UPS rooms. HFC-227ea has been on the US EPA's list of acceptable total flooding agents since 1994; the EPA lists it with a zero ozone depletion potential and a global warming potential of 3,220, and gives FM-200 among its trade names. FK-5-1-12 has been on the same list since 2002, with zero ozone depletion potential and a global warming potential below 1. Honeywell's manual gives FK-5-1-12 an atmospheric lifetime of about 5 days, against 34.2 years for HFC-227ea.
For both, the EPA's listing says the agent should be used in line with the safety guidelines of the latest NFPA 2001, the clean-agent standard. Firetrace's manual notes that FK-5-1-12 is included in NFPA 2001 and approved for occupied areas as a total flooding agent.
3M stopped making it. In December 2022 3M announced that it would exit all PFAS manufacturing by the end of 2025, including all fluorinated fluids, and would fulfil its existing contracts during the transition. 3M's own PFAS page now states that it completed that exit at the end of 2025. Novec 1230 was 3M's trade name for FK-5-1-12.
FK-5-1-12 itself is not a 3M-only product. The US EPA's list names it under several other trade names besides Novec 1230. For an existing FK-5-1-12 system, the practical question is which agent source the system's manufacturer lists for refills and recharges, because a listed system is approved with its agent. Ask before the next six-monthly check, not after a discharge.
Any of them can protect the UPS electronics. The deciding points are usually the room's ability to hold the agent, the space for cylinders, whether people work in the room, and the batteries. Battery chemistry matters most: a VRLA room, a flooded-cell room and a lithium-ion room each bring their own code requirements, which are set out in the UPS and battery room guide. The design is the fire protection engineer's, and the authority having jurisdiction approves it.
Clean-agent design, installation and recharge are delivered through specialist fire protection subcontractors; for the UPS side of a data centre, see data centre UPS maintenance programmes.
Yes. FM-200 is a trade name for HFC-227ea; the US EPA's list gives it among the agent's trade names.
Not by 3M: 3M completed its exit of PFAS manufacturing at the end of 2025. FK-5-1-12, the agent in Novec 1230, is listed by the US EPA under several other trade names.
Clean agents are listed for normally occupied spaces, but Honeywell's manual says everyone should leave as soon as the pre-discharge alarm sounds.
The agent itself is electrically non-conductive and leaves no residue. The fire's smoke and any decomposition products are a separate matter; see the UPS room guide.
Neither in general. Halocarbons discharge in seconds; inert gases take 60 to 120 seconds but produce no decomposition products. The room and its use decide.
Sources, checked 2026-10-04:
Tell us the site, the UPS and the timing. We reply and quote within 4 business hours, or call 1 (438) 800-0382
Brand names are trademarks of their owners and are used only to identify the equipment we service. We are not the manufacturer and are not affiliated with it.