Which device is used to physically secure an energy source during lockout/tagout procedures?

• A. Tag
• B. Lock
• C. Label
• D. Barrier

Answer: (B)

The core idea is that lockout/tagout relies on a physical means to prevent energy from being reconnected. The device that actually does this is the lock. When a worker applies a lock to the energy-isolating device (like a switch, valve, or breaker), it cannot be operated or reenergized until that lock is removed with the authorized key. A tag is then attached to communicate information and warnings, but it does not stop the energy source by itself. A label provides information, not security, and a barrier is not the standard device used to secure the energy source in LOTO. So, the lock is the device that physically secures the energy source.