84195 - Process Safety Engineering M

Course Unit Page


This teaching activity contributes to the achievement of the Sustainable Development Goals of the UN 2030 Agenda.

Clean water and sanitation Affordable and clean energy Industry, innovation and infrastructure

Academic Year 2019/2020

Learning outcomes

After the course students will be able to assess the risks due to industrial installations (i.e. chemical and process industries), through the application of basic concepts about: classification of hazardous substances, hazard identification, probabilistic assessment of top events and consequence assessment.

Course contents

Requirements/Prior knowledge

Physical and chemical properties of pure substances and mixtures, thermodynamics and phase equilibrium. Fundamentals of fluid mechanics, basic knowledge of main unit operations of the process industry and understanding of their basic control and safety systems through the reading of P&ID Fluent spoken and written English is a necessary pre-requisite: all lectures and tutorials, and all study material will be in English.

Part A (common to 6 ECTS and 9 ECTS courses)

1) Introduction to loss prevention and risk analysis.

Basic notions of safety, hazard and risk. Risk reduction strategies. Inherent safety. The risk assessment procedure. Introduction to relevant regulation.

2) Hazardous properties of substances

Introduction to hazardous properties of materials. Flammability. Toxicity. Environmental damage. The REACH regulation. Classification and labelling of hazardous materials. The material safety data sheet.

3) Hazard identification

Available tools for hazard identification. Analysis of case histories. Safety review. Checklists. What-if analysis. HazId analysis. HazOp analysis. FMECA. Fault tree analysis. Event tree analysis.

4) Frequency evaluation and reliability engineeringBasic notions of probabilities and frequencies. Generic frequencies for loss of containment. Random events and part count. The analysis of complex systems by means of fault trees. Introduction to reliability engineering. Non-repairable components. Repairable components. Reliability databases. The Markov model. Preventive maintenance. Human reliability. Systems reliability.

5) Consequence and damage assessmentSource terms models (liquid, gas, mixed-phase release). Dispersion models for neutral and heavy gases. Models for radiative effects from fire scenarios (pool fire, jet-fire, fireball, flash fire). Models for overpressure effects from explosions (physical explosions, BLEVEs, vapor cloud explosions, confined explosions, runaway reactions). Damage models for heat radiation, overpressure and toxic exposure (threshold and probit approach). Model selection criteria. Introduction to consequence assessment software.

6) Quantitative risk assessmentQuantitative risk assessment studies. Risk indicators: individual risk and societal risk. Risk re-composition. Risk acceptability criteria. Risk mitigation. Area risk analysis and transportation risk analysis. Examples of application.

Part B (only for 9 ECTS course)


The interaction of the industrial activities and the environment. The environmental risk analysis. The environmental compartments. The main forms of environmental damage and related substances. The process flow diagram. Heat and material balances of a process. The fugitive emissions.


Review of the main environmental damage mechanisms. Global warming: a phenomenological view. Stratospheric ozone depletion. Photochemical smog formation. Rain acidification. Eco-toxicity.


Flares and vents. Accidental fire scenarios. The combustion process. Hazardous substance formation in combustion scenarios. Energy aspects of combustion.


Accidental release scenarios of environmental concern. The source term. Water dispersion. Soil dispersion. Case study: oil spill on water.


Lees' Loss Prevention in the Process Industries, S. Mannan editor, IV ed., Butterworth-Heineman, Oxford, UK, 2011D.

A.Crowl, J.F.Louvar, Chemical process safety: fundamentals with applications, III ed., Prentice Hall, New Jersey, USA, 2011

Centre for Chemical Process Safety of AIChE, Guidelines for chemical process quantitative risk analysis (II ed.), New York, USA, 1999

Center for Chemical Process Safety of AIChE, Guidelines for hazard evaluation procedures (III ed.), AIChE, New York, USA, 2008

TNO, Methods for the evaluation of physical effects (Yellow book), Report CPR 14E (III ed.), The Hague, NL, 1997

H. Kumamoto, E. Henley, Probabilistic Risk Assessment and Management for Engineers and Scientists, 2nd edition, IEEE Press, New York, 1996

The above books (sometimes in an older edition) are available at the Biblioteca F.P.Foraboschi, via Terracini 28.

Teaching methods

Classroom lectures


Assessment methods

Exam consists of 3 sections: 2 sections for the 6 ECTS part (part A) and 1 section for the additional 3 ECTS (part B).

  • Environmental engineering students (ERE) will have to take all the three sections.
  • Chemical engineering students (STEM) without the elective course Laboratory of Industrial Safety in their study plan will have to take both sections for part A.
  • Chemical Engineering students (STEM), which have selected the elective course Laboratory of Industrial Safety in their study plan can have 2 options:

- perform additional tasks within the project required in the Laboratory of Industrial Safety course (according to prof. Tugnoli requests) and take only one section for part A.

- take the two parts for part A as other STEM students do


A bonus (+1) will be awarded to students completing all the homework assigned during the course.

Teaching tools

Lecture slides and integrative supporting material will be available on-line.

Office hours

See the website of Giacomo Antonioni

See the website of Valerio Cozzani