Describe what a Layers of Protection Analysis (LOPA) evaluates and how it is used?

• A. LOPA estimates costs of safety measures.
• B. LOPA estimates risk by evaluating independent protection layers and their capability to prevent or mitigate incidents; it helps determine required protection and whether existing layers suffice.
• C. LOPA forecasts weather impacts on equipment.
• D. LOPA is a training course.

Answer: (B)

LOPA evaluates risk by looking at what could initiate an incident, what protections stand between that initiation and harm, and how reliable those protections are when needed. It breaks down a specific hazard scenario into components: the initiating event frequency, the protective layers that can prevent escalation or mitigate consequences, and the likelihood that each independent protection layer will function on demand. By combining the expected effectiveness of these layers, LOPA produces a risk reduction figure and compares the residual risk to an acceptable target. If the residual risk is higher than what’s tolerated, LOPA guides adding or strengthening protections, or making design or operating changes, until the risk target is met. It isn’t about costing, weather impacts, or training courses, which is why this approach is focused on whether the existing independent protection layers are adequate and what additional protection is required.