Which of the following is NOT a component tested during a pre-use SCBA check?

The comfort of the straps is not typically a formal component tested during a pre-use SCBA check. While ensuring that the SCBA is comfortable can contribute to the overall effectiveness and usability of the equipment during an emergency situation, the primary focus during a pre-use check is to ensure that the SCBA is functioning properly and is safe to use.

Pre-use checks usually involve verifying critical safety components such as the air supply gauge, which indicates the pressure of the air in the tank, ensuring that the sealing of the mask is tight to prevent any contaminants from entering, and the functionality of the alarm system, which alerts the user when the air supply is running low. These elements are essential for operational readiness and safety, whereas comfort may be adjusted individually by the user but is not part of the systematic check process.