Which of the following is an active safeguard?

• A. Interlock System
• B. Diking
• C. Double wall construction
• D. Rupture disc

Answer: (A)

Active safeguards are controls that require energy or operator action to prevent a hazard or stop a dangerous condition from developing. An interlock system fits this idea because it automatically responds to signals from sensors to halt or adjust equipment—for example, it can shut a valve or stop a pump when unsafe conditions are detected, preventing escalation without human intervention.

The other options are considered passive safeguards. Diking is a physical barrier to contain spills after a release; it doesn’t actively change the process to prevent release. Double-wall construction provides containment of a contained material but doesn’t adjust the process conditions in real time. A rupture disc automatically relieves pressure when it exceeds a threshold, but it does so without control signals or operator action, and it cannot be reset after it activates.