Which items must be opened and tagged out to ensure isolation?

• A. Switches, sources, disconnections, jumpers, taps
• B. Ground mats and barricades
• C. Tools and PPE
• D. The area can be left alone.

Answer: (A)

Opening and tagging out all energy control points that could energize the equipment is what creates a true isolation. This means identifying every way energy can reach the system and physically disabling it with a lockout device plus a tag. Specifically, you would open electrical switches to cut power, ensure the energy source points are isolated, use disconnections to separate circuits, remove or isolate any jumpers that bypass safety controls, and close or isolate taps that could reintroduce energy through a branch line. When each of these elements is opened and a tag (and lock, if required) is applied, you communicate clearly that the equipment must not be energized and that only the authorized person can remove the lock and tag.

Ground mats and barricades offer protective boundaries but do not by themselves stop energy from being supplied or re-energized. Tools and PPE protect workers but do not isolate the system. Leaving the area unchecked would ignore the needed isolation and create a risk of unexpected energization.