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Final Rule on
Sealing of Abandoned Areas
Single Source Page


MSHA Mine Seal Requirements

The final regulation addresses sealing abandoned areas in underground coal mines. It includes requirements for seal strength, design, construction, maintenance and repair of seals and monitoring and control of atmospheres behind seals in order to reduce the risk of explosions in abandoned areas of underground mines. It also addresses the level of overpressure for new seals.
  • The regulation for underground mine seals includes a requirement for seals designed to 50 psi if the atmosphere behind the seal is inert and requires seals designed to at least 120 psi if the atmosphere is not inert.


  • Sealed areas shall be monitored, whether ingassing or outgassing, for methane and oxygen concentrations and the direction of leakage. Atmospheres with seals of 120 psi or greater shall be sampled until the design strength is reached. Atmospheres with seals less than 120 psi shall be monitored and maintained inert.
MSHA Guidelines for Completing the Seal Design Application - 30 CFR § 75.335(b)
    Section 75.335(b) of the seal final rule requires that seal-design applications from seal manufacturers or mine operators be in accordance with paragraphs (b)(1) or (b)(2). The list of information provided below will assist design engineers who are submitting a seal design to MSHA for approval under the requirements of Section 75.335(b)(1) on or after October 20, 2008. Depending on the type of seal (wall, plug, etc.), and construction details, some of the listed information may not be necessary.

        - Guidelines for the Seal Design Application
Stakeholders Meeting Presentation - April 18, 2008 Approved Seals under the Final Rule Regulatory History of the Seals Rule

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