(104b) Application and Challenges of Layer of Protection Analysis (LOPA) in Mining Processes: Insights into Benefits and Limitations

Layer of Protection Analysis (LOPA) serves as a widely adopted semiquantitative technique within process industries, offering precise insights into hazardous scenarios and aiding risk-based decision-making. It provides rational semiquantitative results without the complexities of full quantitative analysis. However, despite its clear advantages, LOPA is not without limitations, which have been consistently acknowledged since its inception.

This paper reveals the authors’ experiences with LOPA in mining industry processes. Serving as facilitators of the methodology within a multidisciplinary team, both the observed benefits and encountered limitations are studied. Traditional methodologies such as HAZOP and HAZID were used as the foundation for identifying hazardous scenarios.

Several limitations were identified, and certain scenarios were excluded from analysis, including those involving only human layers of protection, events initiated by natural events, and asset integrity related events. The unique challenges posed by certain mining processes, especially those heavily reliant on manual operations, tested the applicability of LOPA. Complex situations, like induction furnace equipment where overheat scenarios can lead to explosive phase transitions upon contact with water and molten metal, presented significant difficulties in identifying independent and effective layers of protection that meet LOPA requirements.

Despite these challenges, it was observed that the benefits of LOPA outweigh its limitations. LOPA enhances participants’ comprehension of the value of each protection layer, enabling safety practitioners to advocate for necessary improvements effectively. It is anticipated that the use of LOPA within the company will continue where relevant. To address human errors, the Safety Critical Task analysis methodology is visualized to better manage critical situations and identify controls to avoid catastrophic incidents.