73499 - Safety and Loss Prevention M

Learning outcomes

The aim of the course is to give students the basic theoretical notions and the technical tools for:

• the identification of hazards;

• the evaluation of the consequences of accidents (through consequence analysis and damage models);

• the evaluation of their occurrence frequency (through basic elements of reliability engineering);

• the assessment of risk measures as a combination of frequencies and consequences.

Knowledge of these issues is necessary to manage safety problems during the whole lifetime of a plant and also to ensure compliance with the safety regulations of the process industries.

Course contents

REQUIREMENTS - PRIOR KNOWLEDGE

First of all, the student should possess the basic skills relating to the Italian language, to mathematics and to English that are typically acquired during high school:

1. with reference to the Italian language, it is advisable for the student to have a C2 level knowledge of the Italian language, according to the Common European Framework of Reference for Languages (CEFR), so as to be able to:

- to easily understand complex texts and specialized topics;

- to express oneself spontaneously, fluently and precisely, using a rich and varied language, with a mastery of the nuances of meaning and textual coherence, even in a formal context;

- to write with coherence, clarity and precision, demonstrating full mastery of grammar and vocabulary;

- to summarize information from different sources, restructuring it in a coherent and concise way;

2. with reference to mathematics, it is in particular appropriate for the student to be able to easily solve algebraic and transcendent equations, also with the aid of a scientific calculator;

3. with reference to the English language, a knowledge of C1 level and in any case no lower than B2 level would be desirable.

In addition, the student should possess the skills that are typically acquired during engineering degree courses, i.e. an adequate mastery of the knowledge and tools of the basic sciences applied to engineering as well as the methodological-operational aspects of engineering, with particular regard to engineering modelling.

The course is offered during the last year of the master degree. This implies that it is in some way "recapitulatory" with respect to the whole study plan. In fact, the analysis of the safety aspects of the process industries and of their risk quantification requires an overall view of the features of these installations, and this view is usually gained only at the end of the studies (not during the studies, not at their beginning).

To fruitfully attend the classes and to fully understand the course contents and to pass the exam without sitting several times, it is necessary to have a robuts knowledge of the fundamentals of termodynamics (specifically, of the mass and energy balances - even in presence of phase transitions and chemical reactions - and of the vapour-liquid equilibria), of fluidodynamics (specifically, of the Bernoulli equation and of the outflow of gas in choked conditions), of the transport phenomena (specifically, of the local balances of mass, energy, momentum), of Boolean algebra, and of the calculus of probabilities.

Classes are in Italian: to fruitfully attend classes, a good comprehension of Italian is necessary (at least a B2 level in Italian is required). For students not understanding Italian, it is possible to study the course contents on readings and bibliography fully in English (however, at least a B2 level in English is required).

COURSE CONTENS for a.y. 2025-2026

1.Introduction to the Course

Risk: the process industry and the Chemical Process Quantitative Risk Analysis (C.P.Q.R.A.), the concepts of risk and safety, risk definitions, risk classification methods (individual risk / collective risk; natural risk / anthropic risk, with the sub-categories of technological risk and industrial risk); industrial risk (conventional risk, specific risk, risk of major accident); elements on the Italian legislation on occupational risk; the Seveso I, II and III directives; the Legislative Decree 105/2015 with its annexes and the relevant implementing decrees; the risk of major accidents in the context of HSEQS disciplines; the risk of major accidents in the context of green chemistry and sustainability. Risk indices: the concepts of frequency and probability; individual / local risk; social risk, with calculation examples (f/N curves (simple frequency / number of fatalities), F/N curves (cumulative frequency / number of fatalities), the expected number of deaths or Potential Life Loss, histograms local risk / number of people present); risk matrices. The procedure for calculating risk: the three phases of the calculation; risk acceptability criteria, with examples of application to local risk, social risk, risk matrices; safety measures (preventive and protective; according to the Swiss cheese model, according to the "shell" model, according to T.Kletz); residual risk and the tools for its management (internal and external emergency planning, land use planning, investigation of accidents, inspections). The subjectability of establishments to Legislative Decree 105/2015: art. 3 and annex 1; lower tier and upper tier major accident establishments; the notification; the safety report; the safety management system for the prevention of major accidents.

2.Hazardous Properties of Chemicals

The hazardous properties of chemical substances: flammability, explosiveness, toxicity, corrosivity, reactivity. In-depth study of the “flammability” property. In-depth study of the "toxicity" property. The CLP regulation. The GHS system (origin and development, classification of chemical substances, pictograms, H-statements, P-statements, hazard phrases, the group of physical hazards and its main classes, the group of health hazards and its main classes, the group of environmental hazards and its class, examples of subdivision of classes into categories, differences between the CLP regulation and the GHS system). The safety data sheet and labeling of chemical substances. The REACH regulation (origin, structure, registration and evaluation of chemical substances, authorization for the production of SVHC substances (with definition of PBT and vPvB substances, endocrine disruptors, PMT and vPvM substances), restrictions on chemical substances).

3. Hazard Identification Techniques

Introduction to hazard identification. The main hazard identification techniques: historical analysss; checklists; safety review / safety audit; index methods; HazId analysis; HazOp analysis; what-if analysis; FMEA / FMECA. Criteria for choosing the hazard identification techniques to apply.

4. Damage Models

Introduction to damage assessment models (input and output data; targets of major accidents and damage levels; the domino effect; the physical effects of fires, toxic clouds, explosions, and their spatial representation). Damage models based on probit equations: the mathematical model; examples of probit equations for fires, toxic clouds, and explosions; the spatial representation of the probability of death). Damage models based on threshold values: examples of threshold values for fires, toxic clouds, and explosions. Use of threshold values for external emergency planning and land use planning around major accident hazard establishments in Italy.

5. Source Term Models

Introduction to the consequences analysis of accidental scenarios (source models, fire models, atmospheric dispersion models, explosion models, with related input and output data). Types of storage tanks and typical storage conditions of chemical substances, the Antoine equation and the gas liquefaction modes. The schematization of accidental releases, with examples of schematizations reported in C.P.Q.R.A. guidelines and schematizations deriving from HazOp analysis. Source models: for liquids released from a hole on a pipe pipe and on a tank; for gases released from a hole on a pipe or a tank; for liquefied gases under pressure (flash of instantaneous releases and continuous releases); for evaporating and boiling pools.

6. Fire Models

Introduction to fire models (definition of fire, the methods of transmission of thermal power and the role of radiation, damage produced by fires, the "single point source" and the "surface emitter" fire models, atmospheric transmissivity). Typical process industry fires (poolfire; jet-fire; fireball; Vapor Cloud Fire (VCF)), with description of the related physical phenomena and their mathematical modeling.

7. Dispersion Models

Introduction to atmospheric dispersion models (what they are; the damage produced by toxic clouds and flammable clouds; classification of dispersion models based on the density of the gas, the speed of release, the duration of the release, the dimensions of the source, the height of the source; differences between dispersion of polluting emissions and dispersion of accidental releases). The meteorological parameters in the planetary boundary layer at the basis of passive dispersion (the wind: module and direction; the atmospheric turbulence and its classification according to Pasquill). Gaussian dispersion models: model for continuous stationary releases, with determination of concentration profiles, isopleths of flammable and/or toxic clouds, mass in the flammability range; model for instantaneous releases, with calculation of the passage time of the cloud. Elements on the dispersion of heavy gases.

8. Explosions Models

Introduction to explosion models (definition of explosion, classification of explosions (physical / chemical); classification of chemical explosions (confined / unconfined; deflagrations / detonations); run-away reactions; damage produced by explosions; mathematical modeling of explosions; TNT equivalence models). Physical explosions, with in-depth analysis of BLEVE: causes, description of physical phenomena, mathematical modeling. Unconfined chemical explosions (VCE): formation and fate of flammable vapor clouds; mathematical modeling of VCEs.

9.Event Trees

Typical post-release event trees (trees for continuous or instantaneous releases of flammable liquids and cryogenically liquefied flammable gases, for continuous releases of flammable gases and flammable gases liquefied under pressure, for instantaneous releases of flammable gases liquefied under pressure; quantified event trees for calculating the probabilities and frequencies of the final accident scenarios). Event trees and safety measures: some examples.

Elements on software codes for consequence analysis.

10. Reliability Engineering - Introduction

Introduction to reliability engineering (distinction between components and systems). Standard failure rates. Standard release frequencies. Elements of Boolean algebra and probability calculus.

11. Reliability Engineering - Components (topic that will almost certainly not be discussed due to lack of time)

Introduction to the reliability of components. The non-repairable component. The repairable component. The component subject to preventive maintenance.

12.  Reliability Engineering - Systems

Introduction to the reliability of systems (typologies, schemes, states of a system). Simple systems describable with the "parts count" methodology. Complex systems describable with the fault tree: construction of the fault tree, qualitative analysis, elements on quantitative analysis. The bow-tie diagram.

13. The Calculation of Risk

Calculation of local and societal risk: examples.

 

Knowledge of the topics covered in sections 1. Introduction to the Course, 2. Hazardous Properties of Chemicals, 3. Hazard Identification Techniques, 5. Source Term Models, 9. Event Trees, 10. Reliability Engineering - Introduction, and 12. Reliability Engineering - Systems is of particular importance for achieving the learning objectives of the AfSIP M course. Within each section, knowledge of the concepts presented in the introductory part, as well as knowledge of the relevant physical quantities and of the variables on which each of them depends, together with the ability to set up the mathematical modelling of processes and systems, is fundamental. Less importance is assigned to the sequence of mathematical steps required to obtain the equations for the engineering modelling of processes and systems, and to the solution of numerical exercises.

Readings/Bibliography

For further study of the various topics covered during the lectures (although not necessary to pass the examination with full marks) the following books may be consulted:

• Lees' Loss Prevention in the Process Industries, S.Mannan editor, IV ed., Butterworth-Heineman, Oxford, UK, 2012
• R.Rota, G. Nano, Introduzione alla affidabilità e sicurezza nell'industria di processo, II ed., Bonomo Ed., Bologna, I, 2024
• D.A.Crowl, J.F.Louvar, Chemical process safety: fundamentals with applications, IV ed., Pearson Education, USA, 2020
• 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 calculation of physical effects (Yellow book - Report CPR 14E), III ed., The Hague, NL, 2005
• H.Kumamoto, E.Henley, Probabilistic Risk Assessment and Management for Engineers and Scientists, II ed., IEEE Press, New York, 2000

You can find all these books (in some cases in one of the previous editions) at the Library F.P.Foraboschi in via Terracini 28; for information about the availability of the books, please contact the librarian (Annalisa Neri, annalisa.neri@unibo.it)

Teaching methods

The teaching methods adopted in the AfSIP M course are based on student-centred learning.

At the heart of the learning process for the AfSIP M course are lectures delivered by the teacher, with explanations of the course’s theoretical contents and presentation of numerical exercises to understand how these theoretical concepts are concretely applied in risk analysis. The studentss are continuously involved through questions aimed at the critical analysis of the theoretical contents and the numerical results obtained, in order to promote active participation in the lessons themselves.

At the end of each lesson, “homework assignments" are given, preferably to be carried out in small groups, with the aim of fostering understanding, deeper study, and reworking of the content presented in the lectures, while progressively developing reflective ability and autonomy. Before the next lesson, the teacher is available in the classroom sufficiently in advance to clarify doubts and help resolve difficulties encountered while carrying out the assignment given at the end of the previous lesson. The “homework assignments" include, among other things, some real case studies to which risk analysis is applied in all its phases.

During the lessons, some recent major accidents will be presented, via video, and discussed, in order to foster understanding of the physical phenomena involved and their mathematical modelling, the identification of the causes of the accidents themselves, and the safety measures that would have prevented their occurrence or mitigated their consequences. Some software tools for risk analysis will also be presented; their application will be carried out as part of the optional course “Laboratory of Process Safety.”

The teacher is committed to promoting an inclusive learning environment in which everyone can participate in the lessons and engage in individual or small-group study under the best possible conditions, with respect for each person’s individual characteristics. However, the promotion of a truly inclusive learning environment requires the constructive contribution and willingness to engage of everyone, both the instructor and the students. Without prejudice to any reports sent to the teacher by the University, for example by the Service for Students with Disabilities and Specific Learning Disorders, any specific needs may be reported to the teacher from the beginning of the lessons, with due respect for confidentiality. By way of example, and without claiming to be exhaustive, specific needs include gaps in prerequisites, difficulties in understanding the explanations provided during lessons or in carrying out the assigned activities, as well as the presence of physical, digital, linguistic, or organizational barriers. Such reports may make it possible to identify, where reasonably possible and in any case within the framework of the University’s provisions and the guidelines of the Degree Programme, personalized strategies aimed at supporting the achievement of the learning objectives of the AfSIP M course.

All students are very strongly encouraged to attend the lessons in person with attention and continuity, attending from beginning to end, taking notes, preferably directly on the slides explained by the teacher and made available before the lessons, asking questions during the lessons, and completing the “homework assignment” after each lesson, preferably in small groups. It is absolutely to be avoided to sit partial tests or entire exams for other courses during the teaching period or immediately after it ends, if this requires suspending active participation in the AfSIP M course, which involves both classroom attendance and completion of the “homework assignments.”

Assessment methods

The AfSIP M examination is aimed at verifying the achievement of the knowledge and skills mentioned above, in accordance with the Dublin descriptors for the second cycle of university studies. In particular, students will be required to demonstrate that they are able to:

• know and understand the theoretical contents of the course;

• apply such knowledge to the analysis and solution of case studies;

• integrate different types of knowledge, formulate autonomous judgements, and address real-world problems, even in multidisciplinary contexts;

• communicate clearly, rigorously, and unambiguously, adequately justifying their statements;

• have acquired self-directed learning skills, useful for deepening and extending the competences developed in the AfSIP M course in their subsequent professional activity.

The examination consists of a written test and an oral examination, held on consecutive working days until all candidates have been examined. Passing the written test is a necessary condition for admission to the oral examination; failure to pass the oral examination entails the need to sit the written test again as well. The written test, consisting of theoretical questions and numerical exercises, is primarily aimed at assessing knowledge and understanding of the course contents, the ability to apply the knowledge acquired, and clarity in presenting the procedures and proposed solutions. The oral examination, covering the theoretical and applivative contents of the course, is mainly aimed at assessing conceptual mastery, the ability to reason critically and independently, the integration of knowledge, clarity of communication, and the ability to apply, connect, and rework the course contents in relation to real-world problems. In the unfortunate event that students are allowed to take the examination remotely, the instructor reserves the right to revise the examination format both for those taking the examination remotely and for those choosing to be examined in person, in order to avoid creating disparities among students.

Passing the examination is possible for students who demonstrate knowledge of the hazardous properties of chemical substances, the measures used to quantify the risk of major accidents, the sequence of the different phases of quantified risk analysis, the main mathematical models, as well as the meaning and units of measurement of the most important quantities involved in each phase, while also being able to solve simple numerical exercises. A higher mark is awarded to students who demonstrate that they have understood and are able to use all the course contents, presenting them with appropriate terminology, identifying the interconnections among the contents themselves, setting up more complex problems, and appropriately applying, in the analysis of safety and risk aspects, the knowledge acquired throughout their entire study programme. Failure to pass the examination is generally attributable to lack of knowledge of several parts of the course contents, superficial and incomplete presentation of the topics, inability to distinguish one accidental scenario from another, lack of knowledge of the methods for estimating the frequencies of accidental scenarios, and inability to solve numerical exercises. In any case, students will be penalised if they are unable to independently retrieve information about the AfSIP M course where such information has been made available to all students, as well as if they send the teacher emails containing questions whose answers are provided on the teacher’s and AfSIP M course webpages, on the Virtuale platform, and in the slides presented during the first week of lectures.

During the examination, the use of artificial intelligence is prohibited, as is any access to the internet and the use of any electronic device other than a simple scientific calculator with no file-storage functions; any such use constitutes a violation of academic integrity.

The examination may be taken on one of the 6 annual examination dates set by the teacher and published on AlmaEsami, by registering for the examination session on AlmaEsami.

In order to avoid annoying the teacher, it is strictly forbidden to “try” the examination. To test one’s preparation, students may use the exercises in the course slides, the “homework assignments”, the glossary of definitions, the gallery of tables, the gallery of graphs and figures, the gallery of formulas not included in the summary of formulas, the quizzes, and the sample written test. Students should sit the examination only when they can revise the course slides accurately and fluently and when they can solve the exercises correctly and quickly.

Further information about the examination is available in the AfSIP M examination regulation and in the introductory course slides, both available on Virtuale. For anything not explicitly mentioned on the AfSIP M course webpage or in the AfSIP M examination regulation available on Virtuale, the provisions of the University Teaching Regulations shall apply.

Teaching tools

Personally taken lecture notes.

Material made available by the teacher [available from the start of the lessons for one calendar year on the Virtuale e-learning platform; access restricted to students who have the AfSIP M course in their study plan for the 2025/2026 academic year or for one of the previous years]:

• slides used by the teacher during the lessons

• “homework assignments" given after each lesson

• summary of formulas for numerical exercises and for the written exam test

• glossary of definitions

• gallery of tables, gallery of graphs and figures, gallery of formulas not included in the summary of formulas

• supplementary documents

• supplementary audio and video materials

• quizzes

• example of a written exam test and its solution

• specific software 

The teacher does not make video recordings of the lessons available.

Office hours

See the website of Sarah Bonvicini