Abstract: A filter apparatus for a welding mask having airways passage forming structure including a pair of filtered remote inlets and including an intermediate mouthpiece whereby filtered ambient air may be supplied to the mouthpiece. An exhaust structure is communicated at one adjacent point with the mouthpiece and includes a remote outlet. The outlet is provided with a one-way check valve as are each of the inlets and the airways passage forming structure from which the inlets and outlets are supported each comprise U-shaped clips for clampingly engaging an adjacent marginal portion of a welding mask.