Which part of the face should a respirator cover when used for dust protection?

• A. Nose
• B. Mouth
• C. Both nose and mouth
• D. Chin only

Answer: (C)

For dust protection, a respirator must seal over both the nose and mouth. If only the nose is covered, gaps around the mouth can let dust in; if only the mouth is covered, dust can bypass through the nose. Covering both areas creates a continuous seal around the breathing passage, so air is forced to pass through the filter. A proper fit also requires adjusting the nosepiece and straps and performing a fit check to minimize leaks. This full-face seal is essential to effectively reduce inhalation of dust in a mining environment.