ICAO Levels A, B and C - what's the difference?

It is mandatory that all foams used in civilian airports must be approved to ICAO Level A, ICAO Level B or ICAO Level C standard. But what is the difference between these standards?

ICAO Level A

In order to obtain ICAO Level A certification the foam concentrate, once proportioned correctly, must extinguish a 2.8m² hydrocarbon fire within the given specifications (see table below).

The application rate for the ICAO Level A test is 4.1 L/min/m².

ICAO Level B

In order to obtain ICAO Level B certification the foam concentrate, once proportioned correctly, must extinguish a 4.5m² hydrocarbon fire within the given specifications (see table below).

The application rate for the ICAO Level B test is 2.5 L/min/m².

ICAO Level C

In order to obtain ICAO Level C certification the foam concentrate, once proportioned correctly, must extinguish a 7.32m² hydrocarbon fire within the given specifications (see table below).

The application rate for the ICAO Level C test is 1.75 L/min/m².

ICAO Level C test has been designed to permit substantially reduced quantities of foam and water to be available on fire trucks (for further information, please refer to the OTAC document on Rescue and Fire-Fighting Management of Extinguishing Agents here.)

ICAO Level C places increased emphasis on

• Impacts of fluctuating water pressure

• ARFF vehicle monitor application rates, i.e. regular produced foam testing.

Useful links

• OTAC document: "Rescue and Fire-Fighting Management of Extinguishing Agents" (pdf)
• Asia Pacific Fire Magazine article: "Proposed ICAO Fire Test Changes Compromise Fires Safety" (pdf)