Which type of foam does not require an aeration device?

AFFF (Aqueous Film-Forming Foam) is specifically designed not to require an aeration device because it forms a thin film of foam that can spread over the surface of flammable liquids. This film helps to suppress vapors and provides a barrier to prevent ignition.

In contrast, other types of foam may require air to create the appropriate bubble structure necessary for effective expansion and suppression. For example, IFR (Independent Foam Ratio) foams involve a different formulation that often necessitates specific aeration techniques to ensure that the foam achieves its intended performance. Protein foam is a natural foam that can rely on the aeration process but is less effective without proper expansion. Low expansion foam typically uses aeration to generate the desired volume of foam needed for firefighting applications.

Thus, AFFF's unique formulation allows it to perform effectively without the need for an aeration device, making it suitable for rapid deployment in emergency fire situations.