There are many different types of fire suppression systems. Each system relies on a different agent to extinguish the fire. Sprinkler systems use water to suppress fire when ordinary combustible materials ignite. But depending upon the fuel source in a location, water may not be a suitable suppression agent. Alternative fire suppression systems include those that use inert gases, wet chemical agents, dry chemical agents, and foaming agents. 

Foam fire suppression systems are always an option when considering the best choice for your building or property. However, they might not always be the best option. Foam fire systems are usually reserved for specific buildings with special fire suppression needs. To understand why foam fire suppression systems don’t work well for most buildings, it’s essential to understand how they work.

The Basics of Foam Fire Suppression Systems

Foam fire suppression systems are generally used in locations where flammable liquids are stored in tanks. If a fire breaks out in these tanks, a foaming agent will suppress vapors at the top of a flammable liquid, cutting off the supply of oxygen. Water is a poor suppression agent in these environments because it is heavier than most flammable liquids. This trait would cause water to sink to the bottom of the tank while the flammable materials continue to combust. Additionally, when water is sprayed onto these tanks, it causes splashing, frequently spreading fire.

Foam is a lighter substance that usually expands when it is discharged onto a fire. It creates a foam blanket that protects the flammable liquid from the atmosphere. This process smothers a fire and destroys the potential for further combustion. It also drops the temperature of the flammable liquid it encounters. 

Because of these traits, foam fire suppression systems are generally reserved for niche applications. These systems are a great firefighting tool and can enhance the fire safety of buildings with tanks or reservoirs filled with flammable and combustible liquids. The National Fire Protection Association, or NFPA, outlines the use of foam in aircraft hangers. They are also commonly featured in hydrocarbon processing facilities, such as refineries. In these settings, foam fire suppression agents are a great option. 

When to Consider an Alternative to Foam Fire Suppression Systems

As you can see, foam fire suppression systems are a key fire safety tool that can keep certain hazardous environments safe. However, aside from these very narrow uses, foam is generally not the best option for the vast majority of buildings. There are several reasons to avoid using expanding foam unless you must, such as:

• It won’t extinguish some fires: Fire fighting foam relies on its ability to smother a fire atop a combustible liquid to extinguish fires. It creates a barrier between two materials – oxygen and fuel. Unless the fire is in a contained space at the surface of flammable liquid, the foam may be ineffective. Foam cannot effectively extinguish fires that are spread out across more dimensional space. 
• It can make fire conditions more dangerous: Foam can actually make fire conditions more hazardous in some settings. For example, when encountering fires involving high voltage electricity, foam can act as a conductor. Like water, it allows the electrical current to pass through the material, increasing the risk of electrocution. Foam is also a poor suppression agent when fires cause metals to burn. Again, it is the water contained in foam that makes it hazardous to these fires. If water – or water contained in foam – hits burning metals, a chemical reaction can occur. This chemical reaction can cause an explosion that can be incredibly dangerous to people or property in the vicinity. 
• Foam can damage property: The discharge of foaming agents can damage any property within the building. These systems are commonly used in airport hangars because of fuel storage, but some hangars opt for an alternative fire suppression system even in this setting. The reason for this choice is because foam can be incredibly damaging. Once discharged, it can ruin other physical assets, including vehicles, aircraft, tools, and other systems in the building. The cost of replacing equipment or downtime associated with increased asset loss can be hefty. In settings where roam isn’t required, the risk of damage to other equipment outweighs any benefit that could be provided.
• Foam is not environmentally friendly: Fire suppression foam – and especially expansion foam – is created using materials with unique chemical properties. It can be no surprise that these chemicals are not necessarily great for the environment. If the foam suppression agent escapes the contained area after a fire, it can cause environmental damage. The resulting mitigation efforts and potential fines pose a serious risk for any company. 
• Foam fire suppression systems are costly: Foam fire systems are incredibly expensive. They are usually more costly to install and maintain than other alternatives. And if the discharged foam isn’t disposed of properly, it can cost a tremendous amount to clean up properly. 

There have been some breakthroughs in foam technology that have helped to bring down the price in recent years. Additionally, protein-based foams pose less of an environmental threat than older alternatives. However, despite advances in technology, foam fire suppression systems remain a poor fit for most structures. 

The cost associated with these systems – including any environmental remediation and maintenance – outweigh the benefits. This fact is especially glaring when you consider less expensive and damaging alternatives. While some buildings and industries, such as airport hangars, must install a foam fire suppression system, most other structures have options. 

Alternative fire suppression systems could include water-based sprinkler systems, carbon dioxide/inert gas suppression systems, or wet/dry chemical agent fire suppression systems. These alternatives often have fewer costs associated with them. They pose less of a threat to the surrounding environment. And they often have minor cleanup or damage associated with the aftermath of a fire.

Selecting the right fire suppression system to meet the unique needs of your building or property is no easy task. There are many factors to consider. To learn more about selecting the right system for your business, contact Legacy Fire today!