LOPA versus COVID – Return to sustainable living

ABSTRACT

Layers of Protection Analysis (LOPA) is widely used in process industries to design the plant protection systems. This method considers the occurrence of a hazard as an initiating event, leading to catastrophic failures, then examining the adequacy of Independent Protection Layers (IPLs) to mitigate the risk. LOPA methodology was applied to an encounter with the covid infection as an initiating event and then independent protection layers, namely health safeguarding protocols, such as social distancing, ventilation, hand hygiene, face mask and vaccination were assigned to mitigate the risk of infection and fatality. It was concluded that LOPA can also be applied to the risk of covid infection which can evaluate a numerical value for the death risk frequency, in order to manage the transmission risk to a tolerable level. The latter is the fatality risk due to seasonal flu. This paper adopts process safety LOPA methodology to covid infection risk, by initially calculating a transmission rate and then evaluates the safeguards’ probability of failures in order to develop a ‘Covid Fatality Metric’ which is the measurement tool, to manage the virus spread. The input data is based on public domain covid infection statistical data. The covid transmission rate in public is statistically calculated with random number sampling to simulate the random pattern of virus person to person infection in the community. The success of the covid protection protocols is probabilistic and depends on the public compliance which are modelled by observational surveys. The methodology is flexible enough to be applied to all public places. Whilst covid prevention compliance surveys are possible for smaller communities such as offices, for a larger population, it is proposed to use CCTV digital image processing for the public compliance measurements. © 2021 IChemE