Protection Against Mine Gases, 1954, J. J. Forbes & G.W. Grove

FIGURE 4.—Cross Section of BM-1447 Self Rescuer: a, Molded-rubber body; b, cartridge; c, nose clip; d, lever arm; e, outer lid; f, plunger; g, inner lid; h, inhalation valve; j, mouthpiece; k, exhalation valve; l, filter material; m, moisture absorbent; n, hopcalite.

As indicated by its name, the self-rescuer is intended for use as a device by means of which a person may escape from an atmosphere contaminated with carbon monoxide and is approved for that purpose only. It should not be used for entrance into a carbon monoxide-contaminated atmosphere, except to get to an uncontaminated area in a mine where a barricade might be built or to escape to fresh air.