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.
This application is a division of application Ser. No, 10/798,581 filed on Mar. 11, 2004 now U.S. Pat. No. 6,886,563 which is a division of application Ser. No. 10/395,975 filed on Mar. 25, 2003now U.S. Pat. No. 6,722,366, which is a division of application Ser. No. 09/2 18,930 filed on Dec. 22, 1998 (now U.S. Pat. No. 6,568,392), which is a division of application Ser. No. 08/612,527 filed on Mar. 8, 1996 (now U.S. Pat. No. 6,123,077), which is a continuation-in-part of application Ser. No. 08/507,449, having a U.S. filing date of Sep. 11, 1995 (now abandoned), from international Application US95/02790 (WO 95/02790) filed under the Patent Cooperation Treaty on Mar. 9. 1995.
