CHEMICAL ENGINEERING TRANSACTIONS
VOL. 77, 2019
A publication of
The Italian Association
of Chemical Engineering
Online at www.cetjournal.it
Guest Editors: Genserik Reniers, Bruno Fabiano
Copyright © 2019, AIDIC Servizi S.r.l.
I SBN 978-88-95608-74-7; I SSN 2283-9216
Integrated Explosion Risk Assessment for the Workplace
in a Process Plant
Adam S. Markowski
a,
*, Pawel Wąsowicz
a
, Bruno Fabiano
b
a
Lodz University of Technology, Faculty of Process and Environmental Engineering, Department of Occupational Safety
Engineering, 90-924 Lodz, Wolczanska 213, Poland
b
DICCA, Civil, Chemical and Environmental Engineering Department, Polytechnic School, University of Genoa, Via Opera
Pia 15, 16145 Genoa, Italy
adam.markowski@p.lodz.pl
The improvement of health, safety and protection of workers at risk from explosive in the workplace is
governed by the European ATEX Directives requiring the employer to carry out a risk assessment for possible
explosion scenario. In order to determine explosion risk, the recently proposed methodology ExLOPA requires
the identification of the explosion scenario and its structural elements, conventionally by applying different
Process Hazard Analysis methods. This paper presents a novel strategy based on the combination of an
expert system for explosion scenario identification (ExSys), with subsequent application of ExLOPA method.
An expert system (ExSys) employs values from ad-hoc prepared engineering databases to identify the
explosion loss event tailored for the selected target process and the given workplace. Subsequently, an
explosion barrier model is developed, to provide data for a representative explosion scenario, which is finally
used for explosion risk assessment by the ExLOPA methodology. The proposed technique supports and
extends the application of the Layer of Protection Analysis especially for safety assurance assessment of risk-
based determination for chemical, petrochemical, pharmaceutical, energy, food, wood and other process
industries and related services.
1. Introduction
Notwithstanding the ongoing trend towards inherent safety, raw materials in petrochemical and process plants
(e.g. flammable hydrocarbons) are often impossible to be replaced by inherently safer as evidenced by
explosion and fire accident statistics (Fabiano and Currò, 2012). It is generally acknowledged that risk
assessment is the most effective way to design safety and security safeguards in order to provide safe
workplaces and protect the environment. It also concerns workplaces where explosion atmosphere may occur.
This aspect is governed by the European Directives 1999/92/EC (ATEX 137) and 2014/34/EU, which require
the employer to perform the risk assessment for possible explosion at a workplace. Layer of Protection
Analysis is an amply applied tool that analyses cause-consequence pair, estimating initiating cause probability
on an order of magnitude basis and severity qualitatively and that is currently applied also to emerging risk
(Fabiano et al., 2018). An earlier work by Morkowski (2007) suggested applying the methodology called
explosion layer of protection analysis (exLOPA), which allows for semi-quantitative explosion risk assessment
for process plants where explosive atmospheres occur. However, in order to apply ExLOPA we need to
identify explosion scenario and its structural elements. This task can be adequately fulfilled by different
Process Hazard Analysis methods, even if these techniques require extensive experience, efforts by teams of
experts. Additionally, PHA techniques imply significant time commitments, especially for complex chemical
process units and for branches of industry where risk management is still under development. In order to
simplify the overall process, this paper presents a novel strategy that is a combination of an expert system for
explosion scenario identification (ExSys) with subsequent application of ExLOPA method.
DOI: 10.3303/CET1977087
Paper Received: 1 December 2018; Revised: 18 April 2019; Accepted: 15 July 2019
Please cite this article as: Markowski A., Wasowicz P., Fabiano B., 2019, Integrated Explosion Risk Assessment for the Workplace in a Process
Plant, Chemical Engineering Transactions, 77, 517-522 DOI:10.3303/CET1977087
517