Brand: Partners Size: Pedia and Adult An oxygen mask is a type of mask that facilitates the inhalation of oxygen gas into the lungs from a storage tank. Oxygen masks can be used to cover the entire face (full-face mask) or just the mouth and nose (oral nasal mask). They could be composed of rubber, silicone, or plastic. Under some conditions, a nasal cannula may be used in place of a mask to administer oxygen.