Which of the following is an example of an interlocked safety device?

• A. A routine maintenance checklist.
• B. A warning label.
• C. A machine door that stops the machine when opened.
• D. A color-coded tape.

Answer: (C)

Interlocked safety devices are safeguards that stop or prevent a machine from operating when a guard or door is opened or breached. The door that stops the machine when opened fits this idea perfectly because opening the door triggers a switch or interlock that immediately cuts power or halts motion, reducing the risk of injury by preventing access to moving parts while the machine is energized.

A routine maintenance checklist is a procedural aid used for organizing tasks, not a device that controls the machine. A warning label communicates risk but does not affect how the machine runs. Color-coded tape helps identify areas or hazards but does not stop equipment from operating.