Abstract: An advanced chemical-biological mask for protecting a wearer from chemical and biological environmental contaminants. The mask provides improvements for the wearer in the areas of weight/bulk, fit/comfort, optical compatibility, breathing resistance, communication, and protection. The mask includes a facepiece, eye lens, filter means, inlet and outlet valves, and a nosecup all of which may be molded or integrally bonded to the facepiece which also has a face seal adapted to engage a person's face and form seal therewith. The mask also has a suspension flange which is connected to the facepiece adjacent the seal. An elastic suspension system includes a crown portion for suspending the mask on a person's head and pulling the seal downwardly and into contact with the person's face. The separate nosecup has integral channels to direct the flow of incoming gas along a path adjacent the lens to prevent fogging of the lens.