The positive pressure test involves:

The positive pressure test involves:

• A. Inhaling with a sealed mask
• B. Exhaling with the exhalation valve covered
• C. Breathing normally without movement
• D. Testing the filter material alone

Answer: (B)

The key idea here is how a positive pressure check tests the respirator’s seal. In a positive pressure check, you exhale with the exhalation valve covered, which pressurizes the inside of the facepiece. If the seal is good, the mask should bulge slightly against your face and no air should leak around the edges as you exhale. If you feel air leaking, the seal isn’t complete and adjustments to the straps or position are needed. This is different from inhaling with a sealed mask, which is a negative pressure check, and it’s not about breathing normally or about testing the filter material by itself. The positive pressure test specifically verifies the integrity of the face seal by pressurizing the respirator from inside.

The key idea here is how a positive pressure check tests the respirator’s seal. In a positive pressure check, you exhale with the exhalation valve covered, which pressurizes the inside of the facepiece. If the seal is good, the mask should bulge slightly against your face and no air should leak around the edges as you exhale. If you feel air leaking, the seal isn’t complete and adjustments to the straps or position are needed.

This is different from inhaling with a sealed mask, which is a negative pressure check, and it’s not about breathing normally or about testing the filter material by itself. The positive pressure test specifically verifies the integrity of the face seal by pressurizing the respirator from inside.