Skip directly to local search Skip directly to A to Z list Skip directly to navigation Skip directly to site content Skip directly to page options
CDC Home

Mining Publication: Evaluation of a Sheathed Permissible Explosive Charge for Open Shooting in Flammable Atmospheres

NOTE: This page is archived for historical purposes and is no longer being maintained or updated.

Original creation date: April 1982

Image of publication Evaluation of a Sheathed Permissible Explosive Charge for Open Shooting in Flammable Atmospheres

The Bureau of Mines has developed a prototype nonincendive explosive rock-breaker charge that can be fired unconfined in underground bituminous coal mines without the danger of igniting a flammable atmosphere that might be present. At present, unconfined shooting in underground coal mines is prohibited, but there are situations where the use of such shots would yield an overall improvement in safety. The charge consists of 1-1/2 lb of permissible water gel explosive in the form of a short cylinder 7 inches in diameter and 7/8 inches high, surrounded by a 1/2-inch-thick layer of damp salt, and encased in latex rubber reinforced with cheese cloth. The latex rubber housing provides a charge package that is strong enough to resist rough handling yet is pliable enough to conform to an irregular stone surface. A charge of this shape was found to be more effective at breaking rock than charges with lined or unlined cavities. Incendivity tests in a gallery have shown that the prototype charge will not ignite a flammable methane-air atmosphere when fired. In cooperation with the Mine Safety and Health Administration (MSHA), a test protocol for the certification of these charges as "permissible" for use in flammable atmospheres is being developed.

Authors: RJ Mainiero, JE Hay

Contract/MOA ReportApril - 1982

  • Adobe Acrobat - Portable Document Format (.PDF)

    1.06 MB

NIOSHTIC2 Number: 10002327

Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, TPR-118, :1-9

Contact Us:
  • Office of Mine Safety and Health (OMSHR)
  • National Institute for Occupational Safety and Health (NIOSH)
  • Centers for Disease Control and Prevention
  • 800-CDC-INFO
    TTY: (888) 232-6348
  • New Hours of Operation
    8am-8pm ET/Monday-Friday
    Closed Holidays
  • The U.S. Government's Official Web PortalDepartment of Health and Human Services
Centers for Disease Control and Prevention   1600 Clifton Road Atlanta, GA 30329-4027, USA
800-CDC-INFO (800-232-4636) TTY: (888) 232-6348 - Contact CDC–INFO
A-Z Index
  1. A
  2. B
  3. C
  4. D
  5. E
  6. F
  7. G
  8. H
  9. I
  10. J
  11. K
  12. L
  13. M
  14. N
  15. O
  16. P
  17. Q
  18. R
  19. S
  20. T
  21. U
  22. V
  23. W
  24. X
  25. Y
  26. Z
  27. #