Abstract: A modular reusable elastomeric half-face respirator device includes a modular housing and an elastomeric facepiece. The respirator device can include one or more modular straps, which can be coupled to the filter housing or the facepiece. The modular housing includes a modular filter component configured to hold filter media and to couple to the facepiece. A filter retention mechanism includes an interlocking bayonet-type ratcheting ramp configured to form a seal around the modular filter component, the filter media, or both. The facepiece can include an interfacing portion configured to seal to the face of a person wearing the respirator device, the interfacing portion having a geometry with an outward curvature allowing the interfacing portion to seal to the face by rolling back and increasing contact area between the facepiece and the face. A lock ring receivable in a port of the facepiece can couple the facepiece to the filter component.