A breathing circuit is described for the supplying of low pressure oxygen to a patient that is at risk of hypoxia. The breathing circuit includes a patent airway maintaining device, a first tube that includes a substantially rigid elbow and connectors and a flexible tubular extension. An inflatable bag is coupled to the first tube and has a pressure relief valve that exhausts into the atmosphere. A second tube has a first end that terminates in proximity to the patent airway maintaining device and a second opposed end that terminates external to the first tube. A third tube connects an external source of oxygen to the second tube. A method for an oxygen breathing circuit is also described that further includes the use of a carbon dioxide monitor and the inflatable bag for assisted breathing. The breathing circuit uses only non-metallic polymer or composite type materials.