A surgical mask barrier apparatus for preventing potentially infectious fluids from penetrating through a conventional surgical respiratory mask, which fluid could come in contact with the wearer or enter the respiratory passages of an individual wearing such a mask. The surgical mask barrier apparatus consists of a substantially non-porous formed shield worn in conjunction with a conventional surgical mask. The apparatus includes ridges which cooperate with the structual ridges of a conventional surgical respiratory mask so that air passages are formed therebetween to facilitate normal breathing of the wearer. The apparatus is secured in overlapping orientation to the conventional surgical mask and thus to the wearer through the use of a resilient band. The apparatus further includes elements for removing and detecting the presence of carbon dioxide and excessive levels of moisture which could promote transmission of such infectious fluids if not corrected.