A holistic approach for assessing occupational health risk due to fugitive emissions in petrochemical processes: Leak hazard index (LHI)

Abstract

Fugitive emissions (FE) are unintentional and undesirable leaks of hazardous gases that come from petrochemical piping components such as valves, flanges, and pumps. Fugitive emissions represent a serious threat to the health of petrochemical workers. Based on the source, pathway, receptor (SPR) model, the occupational health (OH) risk due to fugitive emissions is a combination of the health hazards that originate from the source (i.e., process materials, conditions, and design), the leak hazard that represents the pathway, and the exposure hazard that takes place at the receptor. These three hazards bear a resemblance to the severity, probability of leakage, and probability of exposure, respectively. The severity was covered in a previous article related to this study. This paper concentrates on the probability of leakage. The exposure will be covered in a subsequent work to be published later. The OH risk is usually evaluated based on FE amount estimations made based on emission factors developed for different process piping components. This type of evaluation, however, does not consider maintenance that is put in place to control leaks from process piping components. This paper attempts to address and reduce this gap through the development of an index-based method named the leak hazard index (LHI). The LHI is meant to determine the probability of leakages, taking into consideration the effectiveness of maintenance programs that are regularly executed to reduce or prevent leaks from process piping components. The demonstration of the LHI reveals a reliable and realistic evaluation of the probability of leakage.