Application and challenges of layers of protection analysis (LOPA) in mining processes: Insights into benefits and limitations

Abstract

Layers of protection analysis (LOPA) is a semiquantitative technique widely used in process industries for assessing hazardous scenarios and supporting risk‐informed decision making. It provides a balance between the simplicity of qualitative analysis and the detail of quantitative analysis. This paper discusses the authors' experiences with the application of LOPA in the mining and metals (M&M) industry, combined with traditional methods like HAZOP and HAZID, to identify risks. Several of LOPA's limitations became evident, and scenarios involving human factors, natural events, and asset integrity were excluded from analysis. Certain M&M processes, often complex and heavily reliant on manual operations, pose unique challenges to LOPA's effectiveness due to difficulties in isolating independent protection layers: for example, those involving induction furnaces where overheat scenarios can lead to explosive phase transitions upon contact with water and molten metal. Despite these challenges, the advantages of LOPA, such as enhanced understanding of protection layers and fostering effective safety improvements, are significant. The paper anticipates continued use of LOPA within the company, complemented by safety critical task analysis to manage human errors and enhance safety controls in critical situations.