Mining Contract: Smart Escape SCBA
This contract will result in a "smart" self-contained breathing apparatus (SCBA) to be used in escape situations that protects against threat gasses and provides an extended duration of life-sustaining oxygen inhale stream by monitoring the surrounding atmosphere. The use of a hood or mask also allows the wearer to communicate. A smart escape SCBA that only adds oxygen to the filtered air supply when deficiencies are detected could greatly increase the life of the SCBA with the same oxygen bottle or reduce its size and weight for a unit lasting one hour.
Contract Status & Impact
The contract is ongoing.
In the event of an explosion or fire in an underground mine, workers can be exposed to a deficiency of oxygen, an excess of carbon monoxide, or both. These threats can occur as separate conditions or simultaneously. A lack of oxygen in the breathing air can only be addressed via the use of a self-contained breathing apparatus (SCBA) acting as a source of oxygen. An excess of carbon monoxide can also be addressed via the use of an SCBA, but if the threat occurs in isolation (that is, the atmosphere still contains sufficient oxygen to support life) and the concentration of the threat gas is not extreme (< 2%) then the carbon monoxide threat can also be addressed by the use of a filter self-rescuer (FSR). Used together, the SCBA and FSR offer a far more efficient and universally capable life support system than when used in isolation. However, the SCBA does not take advantage of the fact that the surrounding atmosphere likely contains some level of useable oxygen; i.e., the SCBA always supplies the total required oxygen from its limited supply, resulting in a ceiling on its useful life regardless of the level of oxygen in the surrounding air. To address this technology gap, what is needed is a "smart" SCBA that provides filtration and catalytic protection against threat gasses and has an extended duration life-sustaining oxygen inhale stream independent of the threat content and oxygen deficiency of the surrounding atmosphere.
The Smart Escape SCBA (self-contained, open circuit, breathing apparatus) is a hybrid system that provides non-toxic breathing air by using an approved Chemical, Biological, Radiological and Nuclear filter self-rescuer and a catalyst to convert high levels of carbon monoxide to harmless carbon dioxide (CBRN FSR/CO). In addition, the Oxygen Dosing Electronics (ODE) package adds sufficient oxygen to make up for deficiencies detected in the ambient air. By making use of the ambient oxygen, less oxygen is required for a one-hour unit life. This means that the Smart Escape SCBA fits in a smaller and lighter package than a similar-duration conventional SCSR. Alternatively, the use of ambient oxygen could offer a significant increase in SCSR "life" in a unit with the same size as current SCSRs.
The research performed under this contract with Avon Protection involves numerous tasks: (1) definition of performance and system requirements for the Smart Escape SCBA, including keeping environmental stressors within acceptable ranges, providing at least one hour of breathable oxygen supply, and using a mask or hood that allows high-quality voice communication; (2) designing, building, and evaluating prototype units to support extensive bench top testing at Avon and third party labs to demonstrate the device’s capabilities; (3) building sufficient intrinsically safe (per MSHA criteria) Smart Escape SCBAs; (4) testing and evaluation by the National Personal Protective Technology Laboratory (NPPTL), which will include on-site support and training to CDC NIOSH staff.
When complete, the contract accomplishes two objectives. The first is to demonstrate that intrinsically safe electronically controlled oxygen dosing to maintain a minimum safe breathing level (19.5%) is feasible. The second is that the new FSR/CO canister, used with a negative pressure gas mask, is a viable improvement over the W-65 SCSR used by nearly all metal/nonmetal underground miners. This canister and catalyst protect the user from all combustion gases and at least 10,000 ppm carbon monoxide with reduced-temperature inhaled breathing gas, lasts longer than six hours, and allows voice communication during an escape.
The SCBA components and prototype have passed all laboratory testing by the contractor and third parties. The intrinsically safe prototype design was evaluated by the MSHA Approval and Certification Center resulting in no significant issues with respect to intrinsic safety. NPPTL confirmed that the ODE met the proof-of-concept test protocol and that the FSR/CO canisters performed well in the carbon monoxide challenge certification tests except for breathing resistance, which may be improved in the commercial design stage if this device is submitted for certification.