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U.S. Department of Labor

Mine Safety and Health Administration
201 12th Street South, Suite 401
Arlington, VA 22202-5450

EFFECTIVE DATE:   February 8, 2019

EXPIRATION DATE: 3/31/2024                 

LAST VALIDATED: 03/31/2021



                     Administrator for
                     Mine Safety and Health Enforcement

SUBJECT:       Procedure for Permitting the Use of Belt Air to Ventilate Working Sections of Underground Coal Mines


This Procedure Instruction Letter (PIL) applies to Coal Mine Safety and Health (CMS&H) District Managers, Supervisors, Specialists, and Inspectors.


This PIL provides instruction for district personnel regarding the procedures for permitting the use of belt air to ventilate the working sections of underground coal mines. This PIL replaces PIL I12-V-14.

Procedure Instructions

When evaluated and approved by the District Manager in a mine ventilation plan, air from a belt air course may be used to ventilate a working section. MSHA will conduct at least one on-site investigation (a) at any mine proposing to use belt air to ventilate the working section, prior to authorizing such use, and (b) at any mine that has already received authorization to use belt air to ventilate the working section, if that mine has not previously been subject to an on-site investigation in relation to the use of belt air.

Any mine requesting approval to use belt air to ventilate the working section must maintain the level of safety, and therefore not reduce protections currently afforded miners, in underground mines while implementing advances in mining technology. In addition, the operator must comply with the requirements of 30 CFR §75.350(b)(1)-(8).


Section 75.350(b) permits the use of air from a belt air course to ventilate a working section when evaluated and approved by the District Manager in the mine ventilation plan. This PIL is intended to ensure that, prior to permitting the use of belt air to ventilate working sections or continuing the practice after a prior approval, MSHA will have conducted at least one on-site investigation into the safety and health implications of the mine's proposed ventilation system, and that the investigation be conducted by an individual qualified to make the necessary findings to support an appropriate conclusion by the District Manager.


Federal Mine Safety and Health Act of 1977, as amended, 30 U.S.C. § 801, et seq.; 30 CFR §§ 75.323(b) and 75.350(b).

Filing Instructions

This instruction letter should be filed behind the tab marked "Procedure Instruction Letters" in the binder for Program Policy Handbooks and Procedure Instruction Letters.

Issuing Office

Mine Safety and Health Enforcement, Safety Division
Stephen Gigliotti, (202) 693-9479

Don Vickers, (202) 693-9760

Internet Availability

This instruction letter may be viewed on the Internet by accessing the MSHA Home Page ( and then choosing Compliance & Enforcement – Compliance Assistance - Procedure Instruction Letters.


MSHA Program Policy Manual Holders