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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:   April 19, 2012 EXPIRATION DATE: 3/31/2024             
LAST VALIDATED: 03/31/2021


                    Administrator for
                    Coal Mine Safety and Health

SUBJECT:     Examination, Testing, and Maintenance of Conveyor Belt Emergency Stop
                    Devices under 30 C.F.R. § 77.502

This Program Policy Letter (PPL) applies to coal mine operators, Mine Safety and Health Administration (MSHA) enforcement personnel, and interested parties.

The purpose of this PPL is to set forth MSHA's enforcement policy, and to provide guidance to the mining community on the monthly examination and testing requirements of electrical equipment under 30 C.F.R. §§ 77.502 and 77.502-2 involving emergency stop devices or pull cord switches and their respective activating or mechanical arms for conveyor belts.  These standards are intended to ensure the safe operating conditions of electric equipment.

Emergency stop devices or cords are electrical equipment under § 77.502, and must be examined, tested, and maintained by a qualified person to assure safe operating conditions.  Section 77.502-2 requires that such examination and testing be conducted at least monthly.  Program Policy Manual states that MSHA considers control switches or devices to be electric equipment covered by § 77.502.  An emergency stop device includes a pull cord switch and its activating mechanical arm which controls the operation of a conveyer belt.

Therefore emergency pull cord switches and their mechanical arms must be visually examined for physical damage during the monthly examinations.  Although examination of the emergency pull cord switches and mechanical arms does not have to be recorded during the monthly examinations of electric equipment, a record of defective switches and arms must be kept.

On February 3, 2009, an Administrative Law Judge (ALJ) accepted the Secretary's interpretation that an emergency stop device comprised of a pull cord switch and its mechanical activating arm is included in the definition of electric equipment and must be examined and tested monthly under § 77.502.  The ALJ also found that testing must include a functional test and not be limited to visual observation.

The Federal Mine Safety and Health Act of 1977, as amended, 30 U.S.C. § 801 et seq., and 30 C.F.R. §§ 77.502 and 77.1607(cc).

Filing Instructions
This PPL should be filed behind the tab marked "Program Policy Letters" at the back of Volume II in the Program Policy Manual.

Internet Availability
This PPL may be viewed on the Internet by accessing MSHA home page ( and then choosing “Compliance Assistance,” "Compliance Info" and "Program Policy Letters."

Issuing Office and Contact Persons**
Mine Safety and Health Enforcement, Safety Division
Rodney Adamson, (202) 693-9549

MSHA Program Policy Manual Holders
MSHA Special Interest Groups
Coal Mine Operators