MEIRA (Mechanical Equipment Ignition Risk Assessment): Advantages and Limitations of a Semi-quantitative Approach

Abstract

Mechanical Equipment Ignition Risk Assessment (MEIRA) is a methodology aimed at identifying and mitigating hazards associated with the presence of potential effective ignition sources on industrial equipment. This study analyses the application of a semi-quantitative approach to MEIRA on industrial plants and devices, with the aim of assessing the feasibility and effectiveness of such integration. The article presents a case study of the use of MEIRA in certain equipment used in the pharmaceutical industry. The proposed approach combines qualitative expert judgements with quantitative data available in the literature and in the plant. An Operability Matrix is used to correlate the presence of explosive atmospheres with the presence of possible ignition sources and to define the acceptability of the scenarios identified. This methodology allows corrective actions to be prioritised, focusing resources on the most critical scenarios and providing a common benchmark for comparison with other risk analysis techniques (e.g. HazOp). The results highlight the advantages of greater structuring of the decision-making process and better communication between stakeholders. However, the results also reveal intrinsic limitations: dependence on incomplete data, the experience of the working team and the difficulty of representing complex phenomena with simplified metrics.
Through concrete examples, the study highlights how a semi-quantitative approach can be a powerful tool for achieving more consistent, objective and immediately understandable results, improving the management of mechanical explosion risk.