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Mine Safety and Health Administration MSHA's Accident Prevention Program
Safety Idea

Tagging Out Equipment

Safety Something YOU can live with!
Mine Type: All Surface
Category: Maintenance

It is important for equipment operators to know when maintenance is being performed on equipment, and that it is unsafe to operate. This can be accomplished by the mechanic placing a blue indicator, such as a flag, in a prominent location at the operator's cab prior to beginning any maintenance. The purpose of the blue indicator is to notify anyone who wants to operate this equipment that maintenance is being performed and the equipment is unsafe to operate. The blue indicator should remain in place until removed by the mechanic who placed it in the operator's cab.

Equipment with blue flag attached At night, a blue flashlight with a reflector can be used instead of a flag. The flashlight should have a magnetic base or clamp so it can be securely attached. The reflector acts as the indicator in cases where the flashlight batteries expired. The indicators could even include the name of the individual performing the maintenance, so that individual can be contacted with questions about the equipment. Equipment with blue light attached In order for this procedure to be successful, it is critical for all personnel on site to know the meaning of the blue indicator, prior to the procedure being implemented. Other colors, or types of indicators, can be substituted in cases where blue indicators have other meaning.

This procedure is especially useful for equipment without key switches. It would also keep someone with an extra set of keys from starting and moving a machine that had the keys removed during maintenance. (See "Take the Keys")

This suggestion may reduce injuries and fatalities.

Reissued: 04/30/2002
Tag # AP2002-S010

MSHA extends a thank you and a tip of the hardhat to
Jerry Fox of Dell Rapids, S.D.
a winner of a limited edition sticker and patch..

If you have a tip or remedy you would like to pass on, you can e-mail it to If your Accident Buster tip is selected, you will receive credit in this space.