What should be established by the BFC before ventilation when LEL readings exceed certain levels?

Establishing collapse zones is critical in the context of firefighting and rescue operations when Lower Explosive Limits (LEL) readings exceed certain levels. When LEL readings are high, there is a significant risk of explosion due to the presence of flammable gases. A collapse zone is an area around a structure that may collapse if an explosion occurs, ensuring that personnel are kept at a safe distance, minimizing the risk of injury or death from falling debris or blasts.

By clearly identifying and establishing these zones before initiating ventilation, the Battalion Fire Chief (BFC) can create a safer operational environment. This proactive measure is essential for maintaining crew safety while managing the risks associated with high LEL levels, allowing for effective strategy and operation planning in hazardous conditions.

The other options, while important in different contexts, do not specifically address the immediate hazards presented by high LEL readings. Fire lanes and access routes pertain more to clearing pathways for emergency vehicles and personnel, while refreshment areas are unrelated to safety in potentially explosive environments. Thus, the focus on collapse zones is the most critical consideration in this scenario.