|U.S. Department of
Mine Safety and Health Administration|
1100 Wilson Boulevard
Arlington, Virginia 22209-3939
|EFFECTIVE DATE: April 26, 2012|| EXPIRATION DATE: 03/31/2014|
(Re-issue of I10-V-13)
PROCEDURE INSTRUCTION LETTER NO. I12-V-10
FROM: KEVIN G. STRICKLIN
Coal Mine Safety and Health
SUBJECT: Reissue of I10-V-13 - Inadequate Ventilation
This Procedure Instruction Letter (PIL) applies to Coal Mine Safety and Health (CMS&H) District Managers, Supervisors, Specialists, and Inspectors.
The purpose of this PIL is to provide instruction for district personnel regarding the requirements of MSHA's standards that the working face and working places of underground coal mines are ventilated by a sufficient quantity of air so as to continuously dilute, render harmless, and carry away flammable, explosive, noxious, and harmful gases, dusts, smoke, and fumes produced during mining.
In general, 30 C.F.R. § 75.325 establishes minimum quantities of air that must be provided at specified underground locations. For bituminous and lignite mines, § 75.325 requires a minimum of 3,000 cubic feet per minute (cfm) of air at each working face, as determined at or near the face end of the line curtain, ventilation tubing or other ventilation control device. The last open crosscut of each set of entries or rooms on each working section and the quantity of air reaching the intake end of a pillar line must be 9,000 cfm, at a minimum. This also includes sections of the mine that are not operating, but are capable of producing coal by simply energizing section equipment. The working face of longwalls and shortwalls must receive at least 30,000 cfm of air. Section § 75.325 also requires operators to maintain adequate ventilation during installation and removal of mechanized mining equipment.
In addition, when inspectors are present on working sections they should take air measurements to assure ventilation air quantities meet the ventilation plan requirements as required by the standards and visually check that water sprays are properly maintained and functioning.
In some cases, the specified quantities of air may be inadequate to continuously dilute, render harmless, and carry away flammable, explosive, noxious, and harmful gases, dusts, smoke, and fumes. In those cases, enforcement personnel should require changes to the operator's ventilation plan whereby greater quantities of ventilating air will be required and will be specified in the operator's approved ventilation plan.
Providing sufficient air quantity in an underground mine is the principal means of ensuring that flammable, explosive, noxious, and harmful gases, dusts, smoke, and fumes are continuously diluted, rendered harmless, and carried away, as required by Section 303 of the Federal Mine Safety and Health Act of 1977. It is essential to miners' safety and health that each working face is ventilated by sufficient air quantity. Insufficient air quantity allows methane and dust to accumulate, potentially resulting in a mine fire or explosion. Dust accumulations can also cause miners to be exposed to harmful levels of respirable dust, which can bring about the eventual development of coal workers pneumoconiosis (CWP), emphysema, silicosis, and bronchitis, known collectively as black lung.
The Federal Mine Safety and Health Act of 1977, as amended, 30 U.S.C. § 801 et seq., and 30 C.F.R. § 75.325.
This PIL may be viewed on the internet by accessing MSHA's home page at (www.msha.gov), choosing "Compliance Info" and "Procedure Instruction Letters."
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 and Contact Person
Coal Mine Safety and Health, Safety Division
Michael G. Kalich, (202) 693-9714
MSHA Program Policy Manual Holders