Patent Document ID: 20040011363
Application ID: 10316474
Patent Flag: 0

Claim One:
1. A biological defense mask covering at least the mouth, nasal passages, and eyes of a user, said biological defense mask comprising (1) a facepiece, wherein the facepiece can be attached to the user's head to cover the mouth, nasal passages, and eyes, (2) a sealing member attached to the facepiece to form a seal to the user's face and to form a breathing space around the mouth, nasal passages, and eyes, (3) at least one air filter inlet mounted on the facepiece and having a filtering element, whereby air from outside the facepiece, when the user inhales, can pass though the filtering element into the breathing space but air within the breathing space, when the user exhales, cannot pass through the filtering element in a reverse direction, wherein the filtering element can remove biological agents greater than about 0.3 microns in diameter from the air; (4) at least one exit passageway to provide communication between the breathing space and air outside the facepiece, whereby air, when the user exhales, can pass from the breathing space into air outside the facepiece, but cannot pass through the exit passageway in a reverse direction; and (5) a suspension system to attach the biological defense mask to the head of the user and to effect the seal to the user's face; wherein the biological defense mask is lightweight, has a pressure gradient through the filtering element of less than about 15 mm water, and can be continuously worn comfortably by the user for at least 6 hours.