A personal respiratory protection device that comprises a mask body and an
exhalation valve that is secured to the mask body. The mask body includes
(i) a flat central panel; (ii) a flat first panel joined to the central
panel through a fold-line, seam weld, or bond, the fold-line, seam, weld
or bond of the first panel being substantially coextensive with an edge
of the central panel; (iii) a flat second panel joined to the central
panel through a fold-line, seam, weld or bond, the fold-line, seam, weld
or bond of the second panel being substantially coextensive with an edge
of the central panel. At least one of the center, first and second panels
includes filter media. The device is capable of being folded for storage
with the first and second panels in at least partial face-to-face contact
with a common surface of the central panel and, during use, is capable of
forming, over the nose and mouth of the wearer, a cup-shaped air chamber
having a face-contacting periphery.