A self-rescuer device comprises an intake pump that creates a gas stream. The gas stream enters a first sieve that separates carbon dioxide, carbon monoxide, and oxygen from the gas stream to create a mixture. The remaining gas stream flows to a second sieve that separates nitrogen from the remaining gas stream and vents the residual gas to outside of the self-rescuer device through a residual output. The separated mixture is directed to a gas processor separates the oxygen from the mixture. A nitrogen storage canister coupled to the separated output of the second sieve stores the separated nitrogen, and an oxygen storage canister coupled to the separated output of the first sieve stores and concentrates the separated oxygen until a purity threshold is met. Habitable nitrogen and oxygen are metered from their storage canisters and supplied to a user of the device through a breathing mask within an exterior mask shell.