What is a lockout/tagout procedure used for?

• A. To isolate and control energy sources to prevent unexpected machine startup during maintenance or repair.
• B. To lock the doors of the mine.
• C. To schedule maintenance.
• D. To train new workers.

Answer: (A)

Lockout/tagout is a safety practice used to isolate and control energy sources so a machine cannot start up unexpectedly while maintenance or repair work is being done. By shutting down equipment, identifying and isolating electrical, hydraulic, pneumatic, mechanical, and other energy sources, and applying locks or tags, workers create a zero-energy state. This prevents the machine from re-energizing and causing injuries such as unexpected movement, electrical shock, or released pressure. After ensuring all energy sources are safely isolated and verified to be zero, the maintenance can be performed, and the equipment is only re-energized once every lockout/tagout device is removed following proper procedures.

The other options don’t fit because locking mine doors is about security, scheduling maintenance is planning, and training new workers is part of safety education—not the procedure that directly controls hazardous energy during work.