Which body part is critical to check for proper SCBA fit?

Checking the face for a proper seal is essential when ensuring that an SCBA fits correctly. A proper seal around the facepiece is crucial because it prevents contaminants from entering through any gaps that may exist between the user's face and the mask. If the facepiece does not fit snugly, it can lead to exposure to harmful substances, which defeats the purpose of using the SCBA. The effectiveness of the apparatus is directly linked to how well the facepiece seals to the user’s face, which is why this aspect is a primary focus during fit checks. Ensuring that the facepiece conforms well to the contours of the face is critical for both safety and performance during operations.