Abstract: A method for making a filtering face mask that comprises providing a fluid-permeable multi-layered mask body comprising a structural supporting layer and a filtration layer, the multi-layered mask body being configured to fit over the nose and mouth of a person and having an aperture disposed therein; providing an exhalation valve comprising a base portion and a deformable hollow plastic extension member that extends from the base portion to a tip; inserting the tip through the aperture; and deforming the extension member so as to make an effective seal between the exhalation valve and the mask body.

Abstract: Method for making a filter cartridge that is suitable for attachment to a respiratory mask. The method comprises the steps of (a) providing a mass of filter material; (b) providing a filter cartridge housing that has an inlet and outlet and a sidewall that includes sheet material; and (c) thermoforming the sheet material of the housing sidewall around at least part of the mass of filter material to place the housing sidewall in direct contact with the mass of filter material to encapsulate the filter material so that fluid is prevented from passing through the filter cartridge from the inlet to the outlet without being filtered by the mass of filter material.