Foam, also froth
An aerated solution that is used for fire prevention and fire-fighting. Foam is an efficient agent for extinguishing most liquid petroleum fires. Foams are divided into low, medium and high ranges of expansion.
- Low-expansion foam – Expansion in volume of up to 20 times of the quantity of water used.
- Medium-expansion foam – Expansion 20-200 times.
- High-expansion foam – Expansion 200-1000 times.