Which is the most accurate safety practice when performing maintenance on equipment that could be energized?

• A. You can work with power on if you are careful.
• B. Post a sign and proceed.
• C. Only use a single-handed technique.
• D. Lockout/tagout procedures should be performed to isolate energy sources.

Answer: (D)

Isolating all energy sources before maintenance is performed is the essential safety practice here. Lockout/tagout means you shut down the equipment, physically isolate electrical, hydraulic, pneumatic, thermal, and other energy sources, apply a locking device to the energy-isolating means, and attach a tag that communicates that maintenance is in progress. This prevents accidental re-energization and releases of stored energy while work is being done. After ensuring there is zero energy, you can safely proceed with the maintenance, and when finished you remove the locks and tags in the proper sequence so the equipment is re-energized only when it’s safe. This approach protects you from unexpected startups, stored energy releases, or residual pressures that could cause harm. Other options fall short because they don’t provide a real barrier to energizing the equipment or controlling stored energy, which is why they’re not safe substitutes for lockout/tagout.