Which statement is true regarding auxiliary agents in ARFF operations?

In ARFF (Aircraft Rescue and Fire Fighting) operations, auxiliary agents play a crucial role in enhancing firefighting efforts, particularly when used in conjunction with primary agents. The statement that auxiliary agents need to be compatible with primary agents is significant because the effectiveness of firefighting operations can hinge on how well these agents work together. Auxiliary agents are often designed to enhance the suppression capabilities of primary agents, ensuring a more effective response to various types of fires, especially with flammable liquids or solid fuels.

When combining agents, it is essential that they do not react negatively, which could lead to reduced effectiveness or create additional hazards. Therefore, selecting auxiliary agents that are compatible with the primary agents employed is vital for optimizing fire suppression effectiveness. This compatibility ensures that the agents work in harmony, providing improved control over the fire and minimizing risks to personnel and equipment.

In contrast, options suggesting that they can be used on any class of fire, must be incompatible, or are optional, do not accurately represent the necessary strategy of integrating agents in a cohesive and effective manner during firefighting operations.