OSHA 10-Hour Construction ReviewFocus Four HazardsHard

A worker is performing maintenance on a large industrial mixer. To prevent accidental startup during the maintenance, the worker has followed proper lockout/tagout procedures. Which of the following is the final and most critical step in verifying the lockout/tagout procedure before beginning work?

  1. APlacing a 'DO NOT OPERATE' tag on the mixer's control panel.
  2. BAttempting to operate the mixer's controls to ensure it will not start.
  3. CVisually inspecting all energy isolating devices for proper placement of locks.
  4. DNotifying all affected employees that the mixer is locked out.
Show answer & explanation

Correct answer: B. Attempting to operate the mixer's controls to ensure it will not start.

The final and most critical step in verifying lockout/tagout is to attempt to operate the machine's normal starting controls. This 'try-out' ensures that all energy sources are indeed isolated and that the machine cannot be accidentally started.

Why the other options are wrong

  • A. Placing a tag is an important step but not the final verification that energy is isolated.
  • C. Visual inspection is necessary but doesn't confirm the energy isolation by trying the controls.
  • D. Notifying employees is an important communication step, but it doesn't verify the energy isolation itself.

Lockout/Tagout Verification

The final and most critical step in a lockout/tagout procedure is to attempt to operate the equipment's normal starting controls to verify that all energy sources are indeed isolated and cannot be accidentally re-energized.

  • Confirms effectiveness of energy isolation.
  • Prevents accidental startup or release of stored energy.
  • Performed by the authorized employee.

Memory trick: Verifying's the key, before you're free.

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