FM-200, Novec 1230 or Inergen: how to choose

In short

FM-200 (HFC-227ea) and Novec 1230 (FK-5-1-12) are halocarbon agents. They are stored as a liquid, put out a fire mainly by taking heat out of it, and are discharged within about 10 seconds. Inergen (IG-541) is a mix of nitrogen, argon and carbon dioxide. It lowers the oxygen level, is stored as compressed gas and is discharged over 60 to 120 seconds. All three are on the US EPA's list of acceptable agents for flooding a room, to be used within the safety limits of NFPA 2001. In 2026 the biggest difference between them is regulation: HFC-227ea is a greenhouse gas controlled under the Kigali Amendment, which Azerbaijan ratified in 2025.

What these systems protect

ISO 14520-1:2023, the international standard for these systems, covers flooding a room with gaseous agents that do not conduct electricity and leave no residue. Chemours and 3M, the makers of FM-200 and Novec 1230, name computer and server rooms, data centers, telecom facilities, museums and archives as typical uses.

In Azerbaijan, the 2025 design code for high-rise buildings, AzDTN 2.7-9, requires water-based automatic suppression in almost every room. Electrical switchboard rooms, transformer rooms, server rooms, archives and similar rooms may get gas or powder systems where this is technically and economically justified.

The three agents at a glance

Is it safe for people in the room?

• Halocarbons. NFPA 2001, the US standard for clean agent systems, allows them in normally occupied rooms at concentrations up to the NOAEL, the level at which no adverse effect was observed. For HFC-227ea the NOAEL is 9.0% and the lowest level with an effect is 10.5%. For FK-5-1-12 the NOAEL is 10.0%.
• The margin depends on the concentration. For "higher hazard" Class A fires under the European standard EN 15004, 3M gives design concentrations of 5.6% for FK-5-1-12, 8.5% for HFC-227ea and 45.7% for IG-541. By 3M's calculation, that leaves a margin of +78.6%, +5.9% and −5.9% against their NOAELs.
• Inert gases. NFPA 2001 ties the limit to oxygen. Below 43% agent (about 12% oxygen), exposure must be limited to 5 minutes; at 43–52% (12–10% oxygen), to 3 minutes. At 52–62% (10–8% oxygen), the system is allowed only in normally unoccupied rooms, and any exposure must stay under 30 seconds. Above 62%, the rooms must be unoccupied and no exposure is allowed.
• Why Inergen contains CO₂. According to the EPA, it increases blood oxygenation and cerebral blood flow in a low-oxygen atmosphere. The design concentration should result in no more than 5% CO₂.
• Warning before discharge. NFPA 2001 requires a pre-discharge alarm and a time delay. Where the delay is omitted, a supervised lockout valve must block the system whenever people are in the room. Russia's SP 485 requires a delay of at least 10 seconds after the evacuation warning starts.
• Novec 1230 as a liquid. 3M's 2024 US safety data sheet classifies it as a Category 2 reproductive toxicant ("Suspected of damaging fertility or the unborn child"). NFPA 2001 lists its NOAEL for room exposure as 10%. At high temperatures it can decompose into hydrogen fluoride; 3M says the amounts are similar to those of other halocarbon agents.

How fast and how much

• Discharge time. In NFPA-based designs, HFC-227ea and FK-5-1-12 are delivered within 10 seconds, inert gases within 60 or 120 seconds. Russia's SP 485 requires at least 95% of the agent within 10 seconds for modular liquefied-gas systems, 15 seconds for centralized ones and 60 seconds for compressed gases. Since July 9, 2026 it allows 120 seconds for compressed gases in tight rooms (leakage parameter up to 0.001 m⁻¹) with a Class A1 fire load.
• Design concentration depends on the standard. Always name the standard next to the number. For FK-5-1-12: 4.5% in the NFPA 2001 annex (Class A), 5.6% under EN 15004 (higher hazard Class A), 5.4% in SP 485 (n-heptane). For HFC-227ea: 6.7%, 8.5% and 7.2%. For IG-541: 34.2%, 45.7% and 36.5%.
• Archives need more agent. For paper, cardboard and textiles in bales, rolls or folders, SP 485 takes 1.3 times the agent mass calculated for n-heptane, against 1.2 for other Class A1 fires.

Cylinders, the room and pressure

• Space. FM-200 is kept as a liquid pressurized with nitrogen to 25 or 41.5 bar. IG-541 is kept as a gas at 200 or 300 bar. Halocarbon makers and the industry association Eurofeu say liquid storage needs far fewer cylinders; none of them give numbers.
• A tight room. NFPA 2001 requires 85% of the minimum design concentration to hold at the height of the highest protected equipment for 10 minutes, or until trained personnel can respond. Its Annex C describes the door fan test that checks this, and the room must be inspected every year or covered by a documented administrative program. SP 485 limits the room's leakage, requires sealed openings and door closers, and says the room must not be opened for 20 minutes after discharge or until the fire service arrives.
• Pressure. An inert gas discharge only raises the pressure in the room. A halocarbon discharge usually lowers it first and then raises it; NFPA 2001 gives an example of −387 Pa followed by +671 Pa. Honeywell requires pressure relief for inert gas rooms in all cases. NFPA 2001 sends designers to the manufacturer's venting procedure, and SP 485 requires a relief opening where the calculation shows one is needed.

Environment and regulation in 2026

• Climate. None of the three depletes the ozone layer. Their global warming potentials, on the IPCC basis used by the Kigali Amendment, EU law and the EPA: 3,220 for HFC-227ea, below 1 for FK-5-1-12, 0 for IG-541.
• Kigali Amendment. HFC-227ea is a controlled substance under the Kigali Amendment to the Montreal Protocol, which phases down HFCs; FK-5-1-12 is not. Azerbaijan deposited its ratification on November 24, 2025. The amendment enters into force for a party on the 90th day after deposit: February 22, 2026, by our count.
• European Union. Since January 1, 2025, Regulation 2024/573 has banned placing new fire protection equipment that contains HFCs such as HFC-227ea on the EU market, unless it is needed to meet safety requirements at the site. FK-5-1-12 is listed in a different annex of the regulation and is not banned.
• United States. The EPA's rules restricting HFC use do not cover fire suppression. But from January 1, 2026 servicing must use recycled HFCs, and from January 1, 2030 new installations must too.
• PFAS. On December 20, 2022, 3M announced it would stop manufacturing PFAS, including fluorinated fluids, by the end of 2025. The announcement does not name Novec. Eurofeu links it to Novec 1230 and says FK-5-1-12 from other manufacturers is available, with the same properties verified in tests. The EU's proposed universal PFAS restriction covers both FK-5-1-12 and HFC-227ea; according to Eurofeu, the 2023 proposal suggested an 18-month transition plus a 12-year exemption for fire suppressants. By May 2026, the EU's risk assessment committee (RAC) had adopted its final opinion, and the socio-economic committee (SEAC) was consulting on its draft; the restriction itself had not been decided. Inergen contains no fluorine.

Maintenance

• NFPA 2001: check the agent quantity and pressure at least every six months. Refill or replace a halocarbon container that has lost more than 5% of its agent or more than 10% of its pressure, adjusted for temperature.
• In the EU, equipment holding 5 tonnes of CO₂-equivalent or more of HFC needs regular leak checks. For HFC-227ea that is about 1.55 kg of agent (our calculation), so nearly every FM-200 system. For fire equipment, an inspection regime that meets ISO 14520 or EN 15004 counts.

How to choose

• People in the room and little space: a halocarbon. By 3M's calculation, FK-5-1-12 leaves the widest margin between the design concentration and the no-effect level.
• Long-term regulatory certainty: Inergen, with zero GWP and no fluorine. In exchange it needs more cylinders, pressure relief and 60–120 seconds to discharge.
• FM-200: it is an HFC under the Kigali phase-down, and new EU equipment with it has been banned since 2025 unless safety requires it. Check the local rules before choosing it.
• Novec 1230 and its equivalents: make sure the supplier can deliver FK-5-1-12 for the life of the system, and follow the EU decision on PFAS.
• Archives: plan for more agent. SP 485 uses a factor of 1.3 for paper in folders and rolls.
• High-rise buildings in Azerbaijan: gas systems go into server rooms, archives and switchboard rooms where justified; the rest of the building gets water-based suppression.

Common mistakes

• Comparing concentrations from different standards. 4.5%, 5.6% and 5.4% can all be correct for FK-5-1-12, under different standards and fire classes.
• Skipping the room test. Without a tight room the agent leaks out before the 10-minute hold time is over. The door fan test checks this before the system is accepted.
• No pressure relief in an inert gas room. The discharge raises the room pressure, and Honeywell requires relief in every case.
• Opening the room too early. SP 485 says to keep it closed for 20 minutes or until the fire service arrives.