What occurs when non-alcohol resistant foam is applied to polar solvents?

When non-alcohol resistant foam is applied to polar solvents, the phenomenon that occurs is that the polar solvents pull water from the foam. This happens because polar solvents, such as acetone or ethanol, have a strong affinity for water, leading to the destabilization of the foam. As the foam is designed primarily to combat hydrocarbon fires, it does not provide the necessary resistance to polar solvents, which can break down the structure of the foam. Consequently, the water component of the foam is extracted, which compromises its effectiveness in suppressing flames and increases the risk of fire spread.

Understanding the interaction between foam and polar solvents is crucial for firefighters, as it highlights the importance of using the appropriate type of foam for different types of fires, especially in environments where polar solvents are present.