What Gas Is Used In Fire Suppression Systems?

Sprinkler systems that spout water may be the most common type of fire suppression system used in most buildings, but they are not the only type available. In fact, there are many applications where using water (or foam or powder) to extinguish the flames could lead to even further damage.

In such situations, a gaseous fire suppression system is often installed because gas can put out a fire without damaging costly equipment. And depending on the type of gas used, there may not even be any clean up required other than cleaning up any mess caused by the fire itself.

Today, there are several different kinds of gases that can be used to suppress a fire. In this post, you will learn which gas is used for fire suppression in certain applications.

Common Gases Used in Fire Suppression Systems

The four most common types of gases used in gaseous fire suppression systems are:

  • Carbon dioxide (CO2)
  • Chemical clean agents
  • Inert gases
  • Halon

Carbon Dioxide (CO2)

Carbon dioxide is one of the more common gases used in fire suppression systems because it is affordable, readily available, and does not require clean up after being discharged. It effectively and quickly extinguishes a fire by removing the oxygen from the space, thereby cutting off the fire’s main fuel supply. But because of how it works, it also means that systems that utilize carbon dioxide should never be installed in occupied areas. When installing a carbon dioxide fire suppression system in a space, the space needs to have adequate venting, so the gas can be removed after the system goes off. Only after the space has been thoroughly vented can people be allowed to enter.

Since carbon dioxide is usually stored at extremely cold temperatures, it should not be used in areas housing sensitive electronic equipment, like electrical cabinets or computer server centers. The reason is because when the gas is released, its low temperature can cause the warm electronic equipment to suffer thermal shock and, in some cases, certain components may even freeze to the point that the equipment is rendered no longer operational.

Chemical Clean Agents

Chemical clean agents are another popular option used in gas fire suppression systems because they are effective at extinguishing fires in areas with electrical equipment, but they are also safe for use in occupied areas. Two of the most used clean agents used today are HFC-227ea and FK-5-1-12.

Clean agents are becoming increasingly popular because they work by removing heat, which extinguishes the fire. They also do not cause ozone depletion and they have minimal global warming potential compared to many other alternatives. This makes them among the most environmentally friendly fire suppression solutions available.

Inert Gases

A lot of gas fire suppression systems use inert gases because they work like carbon dioxide (by removing oxygen), but unlike CO2, inert gases do not remove all the oxygen, making them less of a suffocation risk. This makes inert gas systems suitable for use in areas that are occupied.

Some of the most common inert gases used include:

  • Argonite
  • Inergen
  • Nitrogen

Because inert gas is safe for occupied areas, safe for use around sensitive electronics, and do not damage the ozone, they are like clean agents, but they are not classified as them because unlike inert gases, clean agents can be stored as a liquid or as compressed gas.


Halon was what was used in gas fire suppression systems before inert gases and clean agents started being employed. Like inert gas and clean agents, halon is safe for use around equipment and effective at extinguishing class A, B, and C fires.

The main difference, however, is that halon has been proven to deplete the Earth’s ozone layer, so it has not been used in installation for the last 20-plus years. Despite this, it is important to note that there remain some halon fire suppression systems that are still in service today.

Does Your Gas Fire Suppression System Need Inspected? Contact Metro Fire Inspections Today!

If you have a gaseous fire suppression system installed in your building and you need it inspected or maintained, contact Metro Fire Inspections today at 631-994-0081 or click here to obtain a free quote for service. We are a full-service fire protection services company serving metro New York City and we offer fire system consultations, design, installation, inspection maintenance, and violation remediation. Make sure your building is up to code – schedule your fire suppression system inspection today!