An introduction to Fire Fighting Foam

An introduction to how Firefighting Foam works, the areas it is used and what you need to know. 

How does Firefighting Foam work?

The Fire Triangle:

Any fire needs 3 elements:

• Fuel source
• Heat
• Oxygen

Eliminate any of these elements and the fire goes out!

Aqueous Film-Forming Foam (AFFF) contains fluorosurfactants that allow it to spread rapidly across the surface of hydrocarbon fuels.

When applied, it forms:

• A foam blanket that separates the fuel from oxygen, and
• A thin aqueous film that suppresses flammable vapours

This prevents re-ignition and assists in extinguishing the fire.

 Where is Firefighting Foam used?

 Firefighting foam is used wherever flammable or combustible liquids present a significant fire risk, including:

• Offshore platforms
• Refineries
• Airports and aircraft hangars
• Tank farms and fuel storage depots
• Chemical plants
• Power stations
• Mining operations and heavy equipment protection

Who specifies or buys Firefighting Foam?

• Fire Safety Managers (typically within HSE teams)
• Fire Engineers and Consultants
• Project and Design Engineers
• Operations and Maintenance teams

What approvals are required?

To ensure quality and performance, firefighting foam should meet recognised international standards such as:

European Standard EN 1568

EN 1568 is a European standard that defines the performance requirements for firefighting foam concentrates. Foams are classified based on two key criteria:

• Extinguishing performance (rated 1 to 3, where 1 is the highest performance)
• Burnback resistance (rated A or B, where A provides the greatest resistance to re-ignition)

For example:

• 1A represents the highest level of performance
• 1B indicates excellent extinguishing performance with good burnback resistance

High-quality foams typically achieve a rating of 1B or better, depending on the application.

UL 162

UL (Underwriters Laboratories) is an independent US-based testing and certification organisation that evaluates fire-fighting foams against the UL 162 standard for foam equipment and liquid concentrates. UL 162 is a widely recognised international approval, particularly in the oil & gas, marine, and industrial sectors. Once a product is UL Listed, it is subject to an ongoing follow-up service programme. This includes regular factory audits and periodic sample testing (typically every few months) to ensure the foam continues to meet the original approval standard.

ICAO Level B and Level C

The International Civil Aviation Organization (ICAO) defines two performance levels for fire-fighting foams used in aviation: Level B and Level C. These levels are based on fire test performance, including extinguishing capability and resistance to re-ignition (burnback). Level C is more demanding than Level B, requiring faster extinguishment and improved burnback resistance under more severe fire test conditions.

LASTFire

LASTFire is an industry-developed testing protocol used to evaluate firefighting foam performance for large oil storage tank fires. It is widely specified by major oil companies for high-risk tank farm applications.

MIL-F-24385

A United States Military specification for AFFF firefighting foam used by the Army, Navy and Air Force. It defines the performance and quality requirements for foam used on hydrocarbon fuel fires.

More information on international foam standards can be found in our Knowledge Base here.