- ICAO Level A, B & C
ICAO Levels A, B, and C are performance categories established by the International Civil Aviation Organization (ICAO) to evaluate and classify firefighting foams used for aviation purposes. These levels provide a standardised test to measure the relative performance of a fire fighting foam ability to extinguish a typical fuel fire and resist burnback.
The following table illustrates the increasing fire size and decreasing application rate for fire fighting foam testing, in respect to the requirements of International Civil Aviation Organization, where a move from ICAO Level A (the highest performance standard) to Level C (the lowest).
The table demonstrates that Level A foams are tested under more challenging conditions with higher foam flow rates, making them suitable for rapid and effective fire suppression in critical situations. In contrast, Level C foams, tested with larger fires and lower application rates, are used in less demanding scenarios where rapid suppression is not as critical.
| ICAO Level A | ICAO Level B | ICAO Level C | |
|---|---|---|---|
| Fire Size, Circular Area (m²)1 | 2.8 | 4.5 | 7.32 |
| Application Rate (L/min/m²)2 | 4.1 | 2.5 | 1.75 |
This table compares the performance of firefighting foams based on ICAO Levels A, B, and C, highlighting differences in fire size and foam application rate. Higher performance Level A foams are tested on smaller fire areas (2.8 m²) but require higher application rates (4.1 L/min/m²), while lower performance Level C foams are tested on larger fires (7.32 m²) with reduced application rates (1.75 L/min/m²).
- 1
Fire Size, Circular Area (m²) - Indicates size of the fire surface area used for testing the foam’s effectiveness. Level A is tested with the smallest fire area (2.8 m²), Level B with a moderate size (4.5 m²), and Level C with the largest fire size (7.32 m²)
- 2
Application Rate (L/min/m²) - measures how much foam solution (in litres per minute) needs to be applied per square metre of fire area for effective extinguishment. Level A requires the highest application rate (4.1 L/min/m²), indicating the most intense suppression effort. Level B and Level C progressively require lower rates.
References
- Doc 9137-AN/898, Airport Services Manual: Part 1 — Rescue and Firefighting Fourth Edition, 2015 (International Civil Aviation Organization), ISBN 978-92-9249-815-3