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.