An optimal level of dust explosion risk management: Framework and application

• A thorough quantitative risk analysis, using QRMF, applied to the Imperial Sugar refinery explosion in 2008.
• The hierarchy of safety controls was applied, in sequence, and showed significant risk reduction.
• DESC, as CFD, was used to predict dust explosion consequences in the refinery.
• FTA for dust and hybrid mixture explosions was used to predict the likelihood.

The current research provides guidance on the prevention and mitigation of dust explosion using a Quantitative Risk Management Framework (QRMF). Using concepts drawn from previous studies, the framework consists of three main steps: (i) a new combined safety management protocol, (ii) the use of DESC (Dust Explosion Simulation Code) and FTA (Fault Tree Analysis) to assess explosion consequences and likelihood, respectively, and (iii) application of the hierarchy of controls (inherent, engineered and procedural safety). QRMF assessment of an industrial case study showed that the original process was at high risk. DESC simulations and Probit equations determined the destructive percentages. FTAs revealed high probabilities of explosion occurrence; in addition, detailed individual and societal risks calculations were made, before and after the framework was applied. Based on the hierarchy of controls technique, the framework showed significant risk reduction to the point where the residual risk was acceptable for the process.