How should hazardous energy be controlled before equipment maintenance in accordance with good practice?

• A. Notify the supervisor and continue work with caution.
• B. De-energise only the electrical circuit.
• C. Isolate energy sources, apply lockout/tagout, test to verify zero energy, and secure against re-energisation.
• D. Use a temporary workaround to avoid maintenance.

Answer: (C)

Hazardous energy control before maintenance relies on a robust lockout/tagout process to prevent any energy from moving or restoring while work is being done. The essential steps are to first identify all sources of energy that could affect the equipment—electrical, mechanical, hydraulic, pneumatic, thermal, and stored energy. Then isolate those sources at their points of control so the equipment cannot be re-energised. Apply locking devices (like padlocks) and clear tags to all isolation points, ensuring that only the person who applied the lock can remove it, and that the tag communicates who is responsible and why maintenance is underway. Next, test to verify there is zero energy present with appropriate testing equipment before any work begins. Finally, secure against re-energisation, using group locks or other controls as needed so the equipment cannot be re-energised unintentionally while maintenance is completed.

This approach is superior because it provides a verifiable dead state and prevents unexpected energising that could injure workers, rather than merely telling someone to be careful or only disabling one energy form. Notifying a supervisor and continuing with caution leaves energy sources active or potentially re-energised; de-energising only the electrical circuit ignores other energy forms; and temporary workarounds fail to reliably isolate and prevent re-energisation.