Using quantitative methods to evaluate process risks and verify the effectiveness of PHA recommendations



Federal regulations and internal factors mandate that managers of chemical processes ensure that the process is operating in a safe manner. Traditionally, some form of a qualitative Process Hazard Analysis (PHA) has been used to evaluate the condition of the process, comply with federal regulations (specifically OSHA 1910.119 and EPA 40 CFR 68), and develop recommendations to ensure safe operation in the future. However, by extending what is required, actual process risks can be quantified, recommendations can be better prioritized, and money spent on safety can be allocated appropriately.

One approach that has successfully been used to satisfy all these objectives is outlined in this paper. It requires a combination of qualitative analysis extended by quantitative analysis. Information is initially gathered by a team familiar with the process and safety analysis techniques, actual risks are determined, recommendations are developed as necessary, and the expected success of implementing a particular recommendation is evaluated.