Definitions for "Facepiece"
The portion of a respirator that covers the wearer's nose and mouth (a full-facepiece also covers the eyes). The facepiece should make a gas-tight or dust-tight seal with the face. The facepiece is supported by headbands, and contains inhalation valves, exhalation valves and connectors for the air-purifying cartridges or filters.
That portion of the respirator that covers the wearer's nose and mouth (quarter mask and half mask) or that covers the nose