What is the final step when donning an SCBA before putting on other protective equipment?

The final step when donning a Self-Contained Breathing Apparatus (SCBA) before putting on other protective equipment is checking the face piece for a proper seal. This is crucial because the face piece is the component responsible for providing breathable air to the firefighter. Ensuring an airtight seal is essential for preventing contaminants from leaking in and for maintaining the effectiveness of the SCBA during operations in hazardous environments. A proper seal guarantees that the firefighter can rely on the SCBA to provide clean air, enhancing safety.

While other steps, like tightening straps or attaching the waist belt, are important for fitting and securing the SCBA, they do not directly affect the operation of the breathing apparatus. Opening the air cylinder valve is also a necessary step for activating the SCBA, but it typically happens after ensuring that the mask is sealed properly. Therefore, checking the face piece for a proper seal stands out as the final critical measure to confirm that all is ready for safe entry into an environment where breathable air is compromised.