OSHA #511 Occupational Safety and Health Standards for General Industry course

Which safety guard requires that the machine cannot be started until it's in the correct position?

1. Adjustable guard

2. Self-adjusting guard

3. Interlocking guard

4. Safety bar guard

The correct answer is: Interlocking guard

The interlocking guard is designed specifically to ensure that a machine cannot be activated until the guard is secured in its proper position. This type of safety mechanism is crucial for preventing access to dangerous moving parts while the machine is operating. The interlock prevents operators from starting the machine when the guard is misaligned or not properly in place, which significantly enhances safety by minimizing the risk of injury. In contrast, other types of guards may not provide this level of security. An adjustable guard allows modifications to its position for different tasks but does not inherently prevent machine operation unless additional safety processes are applied. A self-adjusting guard moves to accommodate different operations but may not have a mechanism that stops the machine from starting without being correctly adjusted. A safety bar guard, while providing protection, typically requires manual action rather than having an in-built system that directly prevents the machine from starting based on guard position. The interlocking mechanism, therefore, represents a vital safety feature that directly links machine operation to the secure positioning of the guard.