The ________ procedure will prevent a machine from being started while someone is working on it.

• A. Interlock
• B. Lockout/tag out
• C. Shutdown
• D. Standby

Answer: (B)

Lockout/tagout is the procedure that prevents a machine from being started while someone is working on it by isolating all energy sources and applying locks and warning tags to the energy‑isolating devices. This makes it physically impossible to re-energize the equipment until the lock(s) are removed and the area is verified safe, which protects workers from unexpected startup or energy release. Interlocks are safety devices that can prevent operation under certain conditions but can be bypassed or fail, and they don’t guarantee complete energy isolation. A simple shutdown stops the machine but doesn’t isolate energy and still leaves the possibility of re-energization. Standby isn’t a safety procedure for maintenance and does not prevent startup.