Rebreathing Bag Silicon is also known as Reservoir Bag. These Rebreathing Bags are Reusable. Rebreathing Bags are made of medical grade Silicon. Anesthesia Rebreathing Bags act like a reservoir for expired gases and are used to push gases in the lungs. It is widely used by the military people. Hospital Rebreathing Bags are safe to use and can be cleaned easily They reduce the risk of trauma. Rebreathing Bags are ideally used in circuits and anaesthetisia machines.