By Hamdan Mohamed Yusoff, PhD ECH5502 HAZARD AND RISK ASSESMENT Semester

COURSE CONTENT 1.Accident & Loss Concept 2.Process Safety Management 3.Hazard Identification 4.Risk Assessment 5.Process design & Safety 6.CHRA 7.Permit to Work System Semester

REFERENCES 1.Crowl, D. A. and Louvar, J. F. (2011). Chemical Process Safety, Fundamentals with applications, 3rd Ed., Prentice Hall, New Jersey. 2.Occupational Safety and Health Act 1994 (Act 514) & Regulation and Orders ILBS, Macdonald, D. (2004). Practical Industrial Safety, Risk Assessment and Shutdown Systems for Industry. Elsevier, Oxford. 4.Hyatt, N. (2003). Guidelines for Process Hazard Analysis, Hazards Identification and Risk Analysis. Dyadem Press, CRC Press, Canada. Semester

GRADING SCHEME Test 30 % Quiz & Assignment 30 % Final Exam 40 % Semester

Lecture 1: Accident and Loss Concept Semester

Overview Accidents Models Loss Statistics Perceptions Nature of accident Semester

Definition Accident – is an undesired event that resulted in unwanted deterioration of health of a living organism value of an organization quality of the environment Semester

Safety, Hazard and Risk Loss prevention Safety Hazard Semester

DOSH definition? An occurrence arising out of or in the course of work which result in fatal injury or non-fatal injury. (DOSH, Act 514), P.U.(A) 128/2004 Occupational Safety And Health (Notification Of Accident, Dangerous Occurrence, Occupational Poisoning And Occupational Disease) Regulations 2004 Semester

OSHA Definitions Recordable cases Non-fatal Occupational injuries Occupational Illness Fatal Lost Workdays Non-Fatal cases without Lost Workdays Semester

OSHA Definitions Recordable Cases are those involving an occupational injury or occupational illness, including deaths. Not recordable are first aid cases which involve onetime treatment and subsequent observation of minor scratches, cuts, burns, splinters, etc., which do not ordinarily require medical care. Semester

OSHA Definitions Occupational Illness of an employee is any abnormal condition or disorder, other than one resulting from an occupational injury caused by exposure to environmental factors associated with employment. It includes acute and chronic illnesses or diseases which may be caused by inhalation, absorption, ingestion, or direct contact. Semester

OSHA Definitions Lost Workdays are those days which the employee would have worked but could not because of occupational injury or illness. Also need to account for diminished long term performance. Semester

OSHA Definitions Nonfatal cases without lost workdays are cases of occupational injury or illness which did not involve fatalities or lost workdays but did result in 1.Transfer to another job or termination of employment, 2.Medical treatment other than first aid, 3.Diagnosis of occupational illness, 4.Loss of consciousness, 5.Restriction of work or motion. Semester

Accident Causation Theory “Acts of God” “Pilot Error” – beginning of industrial revolution “Mismanagement” – current legal leanings Semester

Domino Theory Semester

System-Induced Error An accident occurs if a triggering event occurs at a time when the innate error tendencies of humans as determined by performance influencing factor lead to an error in an unforgiving environment Developed during the 1980’s Semester

System-Induced Error Performance influencing factors – Physiological and Psychological state Low motivation Overloaded – Inadequate training Semester

Injury and Loss Statistics There are several different statistics that have been defined and collected by government and industrial agencies LAGGING INDICATOR Semester

Borang JKKP 8 1 Death = 6000 day ( Lost days) Semester

OSHA Injury & Illness Rate OSHA Injury & Illness Rate = (# of Injuries & Illness*200,000)/(Total hrs all employees ) Based on 100 worker-years Semester

OSHA Lost Workdays Incidence Rate Same bases, but use lost workdays Lost Workdays Incidence Rate = (# lost workdays * 200,000)/(Total hrs worked) Semester

Fatal Accident Rate (FAR) FAR=(# of Fatalities x 10 8 )/(Total hrs all employees) Based on 1000 workers’ career Table 1.3 & 1.4 lists several FARs Semester

Is canoeing is much more dangerous than traveling by motorcycle ? Semester

A FAR of 1.2 is reported in Table1-3 for the chemical industry. Approximately half these deaths are due to ordinary industrial accidents (falling down stairs, being run over), the other half to chemical exposures Semester

In Class Assignment The FAR for travel by car is reported as 57 while that for travel by air is 240 1)If the average speed of travel is 80 km/h by car and 400 km/h by air, determine the deaths per million miles travel by car or air. 2)If you are required to make a round trip from Perlis to Johor Baharu, which is the safer mode of transportation as indicated by the statistics? Semester

Solution 2) For a fixed distance, air travel is the safest mode 1) Calculations Semester

Public Perceptions Public Opinion Poll “Would you say chemicals do more good than harm, more harm than good, or about the same amount of each” The Chemical Manufacturers Association (CMA) recently (2000) changed its name to American Chemists Council (ACC) to avoid the word “chemical Semester

Discussion Recognizing (from FAR statistic) that the chemical industry is safe, why is there so much concern about chemical plant safety ? Semester

Chemical plant accidents follow typical patterns. It is important to study these patterns in order to anticipate the types of accidents that will occur. Semester Nature of Accident Process in chemical plant

Accident process (steps) Most accidents follow a three- step sequence: Initiation Propagation Termination Semester

Accident process A worker walking across a high walkway in a process plant stumbles and falls toward the edge. To prevent the fall, he grabs a nearby valve stem. Unfortunately, the valve stem shears off and flammable liquid begins to spew out. A cloud of flammable vapour rapidly forms and is ignited by a nearby truck. The explosion and fire quickly spread to nearby equipment. The resulting fire lasts for six days until all flammable materials in the plant are consumed, and the plant is completely destroyed. This disaster occurred in 1969 and led to an economic loss of $4,161,000. It demonstrates an important point: Even the simplest accident can result in a major catastrophe. Semester

Discuss the accident steps of the previous accident Semester

Types of Chemical Plant Accidents Type of accident Probability of occurrence Potential for fatalities Potential for economic loss FireHighLowIntermediate ExplosionIntermediate High Toxic releaseLowHighLow Semester

Types of loss for large hydrocarbon chemical plant accidents Semester

Causes of losses for the major chemical accidents

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Defeating the accident process  Safety engineering involves eliminating the initiating step and replacing the propagation steps with termination events.  In theory, accidents can be stopped by eliminating the initiating step.  In practice this is not effective: It is unrealistic to expect elimination of all initiations.  What is the effective approach?? Semester

StepsDesired effectProcedure InitiationDiminish (eliminate this step if possible) Grounding & bonding, Inerting Explosion proof electrical Guardrails, Maintenance procedure Hot work permit Human factor design Process design PropagationDiminish (stop propagation) Emergency material transfer Reduce inventories of flammable material Equipment spacing and layout Nonflammable construction material Installation of check & emergency valves TerminationIncrease (to terminate as quick as possible) Fire fighting equipment and procedure Relief system Sprinkler system Installation of check and emergency shutoff valves Semester

Quiz 1 Failure of a threaded 11⁄2 drain connection on a rich oil line at the base of an absorber tower in a large (1.35 MCF/D) gas producing plant allowed the release of rich oil and gas at 850 psi and 40°F. The resulting vapour cloud probably ignited from the ignition system of engine driven recompressors. The 75 high X 10 diameter absorber tower eventually collapsed across the pipe rack and on two exchanger trains. Breaking pipelines added more fuel to the fire. Severe flame impingement on an 11,000-horsepower gas turbine–driven compressor, waste heat recovery and super-heater train resulted in its near total destruction. Identify the initiation, propagation, and termination steps for this accident. Semester

Solution Semester

Terima Kasih | Thank You Semester