What are the two major types of foam used in firefighting?

The two major types of foam used in firefighting are mechanical foam and chemical foam. Mechanical foam is created by introducing air into a solution of water and a foam concentrate, resulting in a stable foam that effectively smothers and cools fires, particularly those involving flammable liquids. This type of foam is typically used in land and marine firefighting applications.

Chemical foam, on the other hand, is produced using chemical reactions between certain materials, generating gas that forms bubbles when combined with water. This type provides rapid surface coverage and is particularly effective against more volatile fuels.

Understanding the distinction between these types of foam is crucial for firefighters in choosing the appropriate firefighting technique based on the nature of the fire they are combating.