Mining Contract: Development of Components for Breathing Escape Apparatus (DSOV/HMC)

Contract Status & Impact

This contract is complete.

The contract generated two final reports—part 1 for the DSOV, and part 2 for the HMC. To receive a copy of either or both of the final reports, send a request to mining@cdc.gov.

Following a catastrophic event, mine workers and rescue teams may be exposed to harmful gases in the mine atmosphere. Breathing air supplies (BAS) technologies are used to isolate the lungs from this atmosphere or provide refuge alternatives where the atmosphere is controlled. Breathing air supplies for underground mining refer to a range of devices and systems that offer respiratory protection to miners in the event of an emergency. Some examples of BAS are self-contained self-rescuers (SCSRs), closed-circuit oxygen breathing apparatus (CCBAs), and gas supplies for refuge alternatives. Advanced BAS technology could improve a mine worker’s chances of surviving a mine disaster.

Working prototypes are needed of (1) docking/switch-over valves (DSOVs) and (2) hoods/masks with passive communication elements (HMCs) that will be used in the current and next generation of escape breathing apparatus. These components must be designed and developed with due consideration to ease of use, compact size, durability and adaptability to selected breathing apparatus. DSOVs would enable connection of two breathing apparatus to allow for a seamless transfer by the user from one device to the other. Hoods and masks are easier to use than current self-contained self-rescuers (SCSRs) fitted with a mouthpiece, allowing for natural breathing through the nose and mouth as opposed to breathing only through the mouth. HMCs also allow speech diaphragms to be incorporated, enabling the wearer to communicate verbally during escape, which is not possible in current SCSR designs.

Under this contract, Essex Industries produced a prototype DSOV that is compact and easy to use in a mine emergency situation by minimally trained users. Essex Industries also conducted research to determine the feasibility of developing one common HMC design for the selected MSHA-approved SCSRs and a NIOSH-approved self-contained breathing apparatus (SCBA). The HMC has a small collapsible form factor and an integrated communications diaphragm. Essex Industries then produced a prototype HMC and demonstrated its functionality with selected SCSRs.

For both the DSOV and HMC research, the goal was to produce technology demonstrators that could be incorporated into breathing devices used for mine escape.