78845 - Chemical Plants

Course Unit Page

  • Teacher Pamela Morra

  • Credits 3

  • SSD ING-IND/25

  • Teaching Mode Traditional lectures

  • Language Italian

Academic Year 2019/2020

Learning outcomes

The student understands the analysis methodologies of process and of industrial plants based on procedures of chemical-physical and biological trasformation of matter aimed at the production of goods and services, as well as prevention and mitigation of habitats modifications induced by anthropic activities or plants.

Course contents

The course aims to provide students with the basic notions of a major accident risk generated by the process industry, of the risk assessment procedure and its control, with specific reference to the main legislative provisions in force. This knowledge can be spent both within the process industries and public offices involved in controlling the risk of a major accident.


Major accident risk

The major accident risk. The concept of risk. The classification of the risks on the basis of the origin and number of the subjects involved. The industrial risk, its classification, the reference legislation.

The process industry. The process industry as source of major accident risk. Plants subject to the regulation on the major accident risk. Mapping of major accident risk in Italy.

The context of the topic major accident risk: the HSEQS disciplines; sustainability. The "stakeholders" of major accident risk.

Hazardous substances

The dangerous properties of chemical substances. Identification of a chemical (names, numbers, formulas). Physical properties important for safety purposes. Flammability and flammability parameters. Toxicity and toxicity parameters used for the purposes of major accident risk. CLP regulation and major accident risk. Safety data sheets.

Major accident risk assessment

Accident scenarios. The initial accident scenarios, the final accident scenarios: toxic clouds, poolfire, jet-fire, fireball, vapour cloud fire, vapour cloud explosions, scenarios of environmental contamination.

Event trees, physical effects and final incidental targets, domino effect.

The phases of risk assessment. Qualitative and quantitative risk analysis.

Phase 1: Hazard identification. Hazard definition; historical analysis; control lists; safety review; hazop analysis; index methods.

Phase 2: consequences assessment of final scenarios. How the magnitude is expressed. Evaluation and mapping of physical effects. Damage evaluation and mapping. Number of deaths.

Phase 3: Frequences assessment. Quantified event trees and estimation of frequences of final scenarios; estimation of frequences of initial scenarios: historical data; fault trees; bow-tie diagram.

Major accident risk control

How the major accident risk is expressed: risk matrix; local risk index and social risk; the representation of major accident risk in italian legislation. Risk acceptability criteria: intollerable risk, tollerable risk, risk in ALARP zone; local risk acceptability; matrix risk acceptability.

Flux diagram of major accident risk assessment: risk reduction and safety measures; residual risk and its management; external emergency planning; accidents analysis and inspection visits; safety management system.


R.Rota, G. Nano, Introduzione alla Affidabilità e Sicurezza nell'Industria di Processo, Pitagora Ed, Bologna, 2007

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

Books are available in F.P.Foraboschi library, via Terracini 28, Bologna. They are intended as texts to deepen the course topics, not as texts needed to prepare for the exam.

Teaching methods

Classroom lessons with slides support.

Assessment methods

Oral exam at the Imola address. The exam cannot be repeated at a distance of less than 2 weeks; from the second time onwards a positive vote will be recorded in any case.

Teaching tools

Lecture notes (better if taken personally). Copy of slides used during the lessons.

Office hours

See the website of Pamela Morra