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Mine Safety and Health Administration MSHA's Accident Prevention Program
Safety Idea

Bleeder Examination Hazards

Safety Something YOU can live with!
Mine Type: All Underground Coal
Category: Ventilation and Longwalls

Since 1996, two miners have been fatally injured while examining bleeders and returns. One miner died when he encountered bad air while climbing over a roof fall that had been properly supported in a bleeder entry. A Miner's Tip titled " Walking Bleeders and Returns" offered Best Practice suggestions related to this fatality.

Recently, two miners who were conducting weekly examinations of bleeders failed to report out of the mine. Searchers later found the miners. One of the miners died and the other miner was hospitalized and later released. The rescue/recovery operation was hampered by high heat, humidity and other poor environmental conditions.

Best Practices

1) Know the environmental conditions before entering the bleeders. Utilize existing AMS systems to monitor bleeders by incorporating temperature and humidity sensors, along with the oxygen, methane and carbon monoxide sensors. Review the AMS information, including trends, prior to entering the bleeders.

2) Adjust the airflow in the bleeders to eliminate hazardous conditions due to high temperature and humidity.

3) Get training on the effects of the heat index, and review monitoring information relative to temperature and humidity.

4) Prepare for the conditions expected by wearing proper clothing and carrying extra fluids.

5) Follow an established check-in/check-out procedure when assigned to work in bleeders or other remote areas of the mine.

6) Provide bleeders and other remote areas of the mine with communication coverage.

7) Pay close attention to changes in air quality when examining areas near seals and gob ventilation taps.

8) Use properly maintained and calibrated testing instruments. Alarms on gas detection instruments for concentrations outside of safe limits must be audible and visual and be distinct for each gas monitored. Using multiple instruments for various gases could provide separate alarms for more than one gas outside of acceptable limits encountered at the same time.

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Issued: 03/04/2010
Tag # AP2010- 97984