In server rooms, electrical switchrooms, laboratories, archives, or any environment containing sensitive equipment, gaseous fire suppression may be specified where water discharge could cause significant secondary damage.
Where sensitive electrical equipment or critical assets are present, water-based suppression may introduce additional damage following discharge. Gaseous systems provide an alternative to prevent facilities from having to trade fire damage for water damage.
Clean agents exist for exactly this problem. In a space where fire is a threat to sensitive equipment, gaseous systems use inert gases or chemical agents to achieve a specified extinguishing concentration throughout the protected enclosure. Knowing which regulations and standards govern their installation and maintenance can keep your facility and business compliant and protected.
What is Gaseous Fire Suppression?
Gaseous fire suppression systems control fire without water by flooding a protected enclosure with an electrically non-conductive extinguishing agent that leaves no residue. This can reduce secondary damage to sensitive electronic equipment and simplify post-discharge clean-up.
When a room is flooded, the entire enclosure is filled with a clean agent to a calculated concentration, not just the seat of the fire. Because the agent leaves no residue, sensitive electronic equipment is less exposed to the secondary damage associated with water discharge.
In the UK, the standard governing how these systems are designed, installed and maintained is BS EN 15004-1, and every agent-specific variant sits underneath it.
What Are the Other Types of Agents?
Two of the main types of gaseous suppression agents are inert gas and chemical agents. Both are clean agents; however, both suppress fire through different means.
Chemical Agents
FM-200 (HFC-227ea), covered by BS EN 15004-5, suppresses fire by absorbing heat and interrupting the combustion chain reaction. It leaves no residue, but carries a high global warming potential and is now moving through a government-mandated F-Gas phase-down. This is already pushing refill costs up.
FK-5-1-12 (Novec 1230), covered by BS EN 15004-2, works the same way. However, at a lower design concentration of around 5.6%, it has a wider safety margin and discharges in roughly 10 seconds. FK-5-1-12 is a fluorinated compound, and its long-term regulatory position should be considered when specifying systems intended to remain in service for many years. 3M discontinued its branded Novec 1230 in 2025; however, other manufacturers are still producing it.
Inert Gas
IG-541 (Inergen), covered by BS EN 15004-10, blends 52% nitrogen, 40% argon and 8% carbon dioxide. The CO2 component stimulates breathing, which helps occupants evacuate faster. IG-55 (Argonite), covered by BS EN 15004-9, is a simpler 50/50 nitrogen-argon mix, commonly used in server rooms and archives.
Both work by displacing oxygen rather than attacking the fire chemically, dropping the room from around 21% to 12–14%. This level of oxygen is low enough to stop combustion while staying breathable for a short amount of time. At around 60 to 120 seconds, discharge is slower than a chemical agent.
The Regulations You Need to Be Aware Of
- BS EN 15004-1: governs design, installation, testing and maintenance for the whole system.
- BS EN 15004-2: physical properties and system design for FK-5-1-12.
- BS EN 15004-5: physical properties and system design for FM-200.
- BS EN 15004-9: physical properties and system design for IG-55.
- BS EN 15004-10: physical properties and system design for IG-541.
- Regulatory Reform (Fire Safety) Order 2005: the legal duty on the responsible person to ensure adequate fire precautions are in place, in England and Wales.
The choice between inert gas and chemical agents depends on factors including enclosure size, available cylinder storage, discharge requirements, environmental considerations and the nature of the protected assets. However, inert gas may be favoured over chemical alternatives due to its relative simplicity, lower consequential damage, and better long-term resilience against tightening environmental regulations.
Where Are Gaseous Suppression Systems Most Useful?
Data centres, archives and heritage collections, switchgear and electrical rooms, marine and offshore installations, and museums. These systems are particularly relevant where water discharge could damage critical electrical equipment, irreplaceable materials or assets that are difficult to restore. For sites with long-term environmental or compliance considerations, inert gas may offer greater long-term resilience against changing environmental regulations.
