Which safety procedure protects workers by controlling hazardous energy sources?

• A. Lockout/Tagout
• B. PPE
• C. Fire Extinguisher
• D. Safe Work Permit

Answer: (A)

Lockout/Tagout is the safety procedure that protects workers by ensuring machines and equipment cannot energize or release stored energy while they are being serviced. It works by identifying all energy sources a machine could use—electrical, hydraulic, pneumatic, mechanical, thermal, chemical, and others—then shutting the machine down, isolating those energy sources, and applying locks (and sometimes tags) to prevent any re-energization. A verification step checks that all energy has been released or blocked before work begins. Only after confirming a zero-energy state does maintenance proceed, and after work is done, the locks are removed in the correct order to restore energy safely. This approach directly addresses the risk of unexpected startup or energy release, which PPE cannot prevent, a fire extinguisher cannot stop, and a Safe Work Permit alone does not guarantee energy isolation.