Local 483 Apprenticeship Practice Exam

Lockout/tagout protects workers by preventing the machine from energizing or releasing stored energy while maintenance is being performed. Before work begins, all energy sources—electrical, hydraulic, pneumatic, mechanical, thermal, gravity, and stored energy—are shut down and isolated. A lock is placed on the energy-isolating device to physically prevent re-energizing, and a tag warns that service is in progress and indicates who is responsible. Only the person who applied the lock should remove it, after work is complete and verification shows zero energy. This approach directly stops unexpected startup or the sudden release of energy that could injure someone, which is why it’s the core purpose of lockout/tagout. While it also helps reduce risks like electric shock or fire hazards, those are potential outcomes, not the primary mechanism. Noise exposure isn’t addressed by lockout/tagout.