This document provides an overview of a university module on health and safety management, risk assessment, and incident investigation. It outlines the module objectives, content, assessment methods, and example assessment topics. The module covers principles of health and safety management, foundations of risk assessment, basic and advanced risk assessment methods, and incident investigation techniques. It aims to move beyond a reactive approach to proactively managing risks through proper risk assessment and safety management systems.

10. Basic steps in risk assessment Classify work activities Identify hazards Determine risk Decide if risk is tolerable Prepare risk control action plan Review adequacy of action plan

22. Traditional Safety Management ACCIDENT Investigate accident - steered by the preconceptions of the investigator Attribute primary cause to unsafe acts Attribute primary cause to unsafe conditions RULE devised forbidding unsafe acts TECHNICAL solution to make conditions safe

25. Time Perception of risk Perceptions of risk and prevention

26. Time Perception of risk Serious accident Perceptions of risk and prevention

27. Time Perception of risk Serious accident Rules and safeguards devised here may be violated when perceptions decay over time Perceptions of risk and prevention

29. Events and Outcomes ws Near miss Hazard Fatality Property damage Major injury Minor injury Event Accident             Incident OUTCOME Environmental damage

30. The Accident Triangle Major or >3 day injury Minor injury Non injury 189 7 1

31. Hale and Hale Model – behaviour in the face of danger Action Presented Information Expected Information Perceived Information Possible Actions Cost / Benefit Decision

32. Human Failure Knowledge- based Rule-based Lapses Slips Exceptional Skill-based (unintended) Errors Situational Mistakes (intended action * ) Routine Violations (intended) * But unintended diagnostic error Reason’s error type classification - ve Safety Culture

37. Initial Status Review OHS Policy Management Review Planning Checking & corrective action Implementation & operation Continual improvement

38. The Main Elements in HSG65 Organising Planning and Implementing Measuring Performance Policy Reviewing Performance Auditing

39. Management system BS 18004: 2008 Initial Status Review OHS Policy Management Review Planning Checking & corrective action Implementation & operation Continual improvement

41. Reactive to Proactive - Safety Improvement Stages Risk Indicators Time & Effort Safety Culture Regulation Lead Management Lead People Lead

55. Basic steps in risk assessment Classify work activities Identify hazards Determine risk Decide if risk is tolerable Prepare risk control action plan Review adequacy of action plan

64. Risk level Estimator Highly Unlikely Likely Unlikely Harmful Slightly Harmful Extremely Harmful TRIVIAL RISK MODERATE RISK MODERATE RISK MODERATE RISK SUB- STANTIAL RISK INTOLERABLE RISK TOLERABLE RISK TOLERABLE RISK SUB- STANTIAL RISK

66. Risk-based control plan RISK LEVEL ACTION (AND TIMESCALE) TRIVIAL No action, no records TOLERABLE No further action necessary: monitor to ensure controls maintained MODERATE Efforts to reduce risk, but costs of prevention should be limited SUBSTANTIAL Urgent efforts to reduce risk: reduction costs may be high INTOLERABLE Work should not be started or continued until risk reduced: no cost constraints for prevention

75. Risk Matrix Extreme 36 30 24 18 12 6 6 Very high 30 25 20 15 10 5 5 High 24 20 16 12 8 4 4 Low 18 15 12 9 6 3 3 Very low 12 10 8 6 4 2 2 Insignificant 6 5 4 3 2 1 1 Risk levels 6 5 4 3 2 1 Likel ihood Severity

83. Steps in advanced risk assessment Cost-Benefit Analysis DEFINE SYSTEM IDENTIFY HAZARDS HAZARDOUS EVENTS HAZARDS EVENTS CONTINUING HAZARDS ANALYSE CONSEQUENCES DECIDE RISK CONTROL STRATEGY VERIFY ESTIMATE/ MEASURE RISKS EVALUATE RISKS NO CHANGE (MONITOR) YES NO IS RISK TOLERABLE? Task-based approach HAZOPS FMEA CHECK-LIST Event Tree Analysis Fault Tree Analysis Event Tree Analysis C Hierarchy Risk Matrix or Risk Calculator 1 in 10 ,000 1 in 1m QRA

89. Principle of HAZOPS INTENTION DEVIATIONS Possible Causes Potential Consequences

92. NO MORE LESS OTHER THAN GUIDE WORDS Principle of HAZOPS INTENTION DEVIATIONS Possible Causes Potential Consequences Inductive logic Deductive logic

98. Exercises Metal cleaning shop

100. Divide system into lines & tanks Local Extract Ventilation Design intention: to provide constant face velocity 5m/sec Fan Filters Face velocity 5 m/sec

101. No Flow Power fails Increased None A Consider emergency concentration power supply

103. HAZOP WORK-SHEET Storage tank T-1 To store flammable reagent at 1.1 bar and 20° C G UIDE W ORD PROPERTY P OSSIBLE C AUSES C ONSEQUENCES A CTION R EQUIRED MORE LEVEL 1. Pump P-1 fails to stop Reagent released Incorporate high level alarm and trip 2. Reverse from process Reagent released Consider check valve Line 2 LESS 3. Pump P-1 cavitates Damage to P-1 Can reagent explode? If pump overheats? 4. Rupture in Line 2 Reagent released Consider alarm and pump shut-down 5. V-3 open Reagent released Consider alarm 6. V-1 open Same Same 7. Tank rupture Same What external events can cause rupture? NO Same as LESS OTHER THAN COM – 8.Wrong reagent Possible reaction Is reagent sampled before POSITION pumping ? AS WELL AS 9.Impu rity in reagent Possible overpressure, if What are the possible volatile impurities? LESS PRESSURE 10. Break in flare or Reagent released Consider low pressure alarm nitrogen lines 11. Loss of nitrogen Tank implodes What i s design vacuum of tank ? 12. CV-2 fails closed Tank implodes 13. PIC fails Tank implodes MORE 14. PIC fails Reagent released via R.valve What is capacity of CV-1 R. valve? 15. CV-1 fails closed Reagent released via Relief 16. V-7 c losed Same as (15) Is V-7 locked open? 17. Overfill tank See (6) Is V-8 locked open?

105. Steps in advanced risk assessment Cost-Benefit Analysis DEFINE SYSTEM IDENTIFY HAZARDS HAZARDOUS EVENTS HAZARDS EVENTS CONTINUING HAZARDS ANALYSE CONSEQUENCES DECIDE RISK CONTROL STRATEGY VERIFY ESTIMATE/ MEASURE RISKS EVALUATE RISKS NO CHANGE (MONITOR) YES NO IS RISK TOLERABLE? Task-based approach HAZOPS FMEA CHECK-LIST Event Tree Analysis Fault Tree Analysis Event Tree Analysis C Hierarchy Risk Matrix or Risk Calculator 1 in 10 ,000 1 in 1m QRA

109. Example: Chlorine storage system Pressure switch Storage tank Relay Pump Valve PT

110. Details of pressure switch design Pressure Bellows Micro-switch Pivot Spring Beam PRESSURE SWITCH Pressure switch Storage tank Relay Pump Valve PT

111. Details of the transmitter design: Normally Open relay Pressure switch Storage tank Relay Pump Valve PT

112. FMEA: estimation and evaluation of risks A B C D E I II III IV Probability level Medium Medium risk risk High risk High risk RP1 RP1 RP3 RP3 Low risk Low risk RP2 RP2 Medium Medium risk risk Severity Category A B C D E Probability level 10 -1 10 -2 10 -3 10 -4 10 -5 Description I II III IV Severity category Minor Critical Major Catastrophic Degree Functional failure – minor injury/ ill health No major damage or serious injury Major damage and/or potential serious injury Complete system loss and/or potential fatality Description Probability value Frequent Probable Occasional Remote Improbable

114. FMEA: worksheet

115. FMEA: summary sheet Rank failure modes according to criticality; Decide actions required to reduce risks; Design measures should be considered as a priority

116. Normally open (NO) cam-activated electrical switch Guard Guard closed closed Guard Guard open open Hazard Hazard

117. Normally closed (NC) cam-activated electrical switch Guard Guard closed closed Guard Guard open open Hazard Hazard

118. Cam operated electrical limit switches

120. Steps in advanced risk assessment Cost-Benefit Analysis DEFINE SYSTEM IDENTIFY HAZARDS HAZARDOUS EVENTS HAZARDS EVENTS CONTINUING HAZARDS ANALYSE CONSEQUENCES DECIDE RISK CONTROL STRATEGY VERIFY ESTIMATE/ MEASURE RISKS EVALUATE RISKS NO CHANGE (MONITOR) YES NO IS RISK TOLERABLE? Task-based approach HAZOPS FMEA CHECK-LIST Event Tree Analysis Fault Tree Analysis Event Tree Analysis C Hierarchy Risk Matrix or Risk Calculator 1 in 10 ,000 1 in 1m QRA

123. “ FIRE” “ FIRE” Fails Fails Success Major Major Fire A A B B C C D D E E Initiating event Detector Valve Water supply Success Success Alarm Major fire Major fire Possible fatalities Possible fatalities Sprinkler might Sprinkler might work work Evacuation of Evacuation of personnel personnel No sprinkler No sprinkler protection protection

125. “ FIRE” “ FIRE” Fails Fails Success P = 0.1 P = 0.1 P = 0.90 P = 0.05 P = 0.05 P = 0.95 P = 0.9 P = 0.1 P = 0.1 P = 0.95 P = 0.05 P = 0.05 P=0.731 Evacuation of Evacuation of personnel personnel No sprinkler No sprinkler protection protection P=0.1 Major fire Possible fatalities Sprinkler might work Major Fire A A B B C C D D E E Initiating Event Detector Valve Water supply Success Success Alarm

127. Major fire Possible fatalities Sprinkler might work Major Fire Initiating Event Detector Valve Water sprinkler Alarm ƒ = 0.1/yr ƒ = 0.0731 /yr ƒ = 0.01/yr “ FIRE” “ FIRE” Fails Fails Success P = 0.1 P = 0.1 P = 0.90 P = 0.05 P = 0.05 P = 0.95 P = 0.9 P = 0.1 P = 0.1 P = 0.95 P = 0.05 P = 0.05 Evacuation of Evacuation of personnel personnel No sprinkler No sprinkler protection protection A A B B C C D D E E Success Success

129. Steps in advanced risk assessment Cost-Benefit Analysis DEFINE SYSTEM IDENTIFY HAZARDS HAZARDOUS EVENTS HAZARDS EVENTS CONTINUING HAZARDS ANALYSE CONSEQUENCES DECIDE RISK CONTROL STRATEGY VERIFY ESTIMATE/ MEASURE RISKS EVALUATE RISKS NO CHANGE (MONITOR) YES NO IS RISK TOLERABLE? Task-based approach HAZOPS FMEA CHECK-LIST Event Tree Analysis Fault Tree Analysis Event Tree Analysis C Hierarchy Risk Matrix or Risk Calculator 1 in 10 ,000 1 in 1m QRA

131. The ‘OR’ Gate ARRIVE LATE A WAKE UP LATE X DELAYED EN ROUTE Y INCORRECT TIME Z TOP EVENT (OUTPUT) INPUT EVENTS Event ‘A’ occurs if (at least) one of X OR Y OR Z occurs OR

132. The ‘AND’ Gate Event ‘A’ occurs if both X AND Y occur

133. FTA –lighting system Fuse Switch Bulb 1 Bulb 2 Power Source Room dark Power off Power supply failed Switch open Fuse Blown Both bulbs burned out Bulb 1 burned out Bulb 2 burned out

134. Risk Assessment Methodologies Human Reliability Analysis (HRA) Richard Booth

135. Machine/ P rocess CONTROLS Display H UMAN- M ACHINE I NTERFACE

136. Human error rates

137. Human Error as a function of stress level Error Rate Stress Level Bored Over-excited

138. Hierarchical Task Analysis ‘HTA’ A process of developing a description of a task in terms of operations - things which people should do and plans - statements of conditions when each task/step has to be carried out

143. Hierarchical Task Analysis ‘HTA’ 0 WIRE A THREE PIN PLUG 1 PREPARE PLUG 2 PREPARE CABLE 3 4 TEST PLUG 2.1 CUT & STRIP OUTER CABLE SHEATH 2.2 2.3 CARRY OUT ASSEMBLY 3.2 3.3 3.4 SELECT AND FIT 13 Amp FUSE 3.5 TIGHTEN CABLE STRIP & REPLACE COVER Plan 0: do in order Plan 2: 1 then 2 then 3 Plan 3: 1,2,3,4 then 5 CUT & STRIP INDIVIDUAL WIRES AS MARKED TERMINATE ALL 3 WIRE STRANDS 3.1 FIT BLUE WIRE IN TERMINAL 1 & TIGHTEN SCREW FIT YELLOW WIRE IN TERMINAL 2 & TIGHTEN SCREW FIT BROWN WIRE IN TERMINAL 3 & TIGHTEN SCREW

145. Risk Decision-making

149. HSE ‘ALARP’ Intolerable Risk Upper Limit Lower Limit Negligible As Low As Reasonably Practicable ‘ALARP’ Broadly acceptable

150. HSE ‘ALARP’ Intolerable Risk Upper Limit: 1 in 1,000 (workers) 1 in 10,000 (public) Risk of death / year Lower Limit: 1 in a million (workers & public) Risk of death / year Negligible As Low As Reasonable Practicable ‘ALARP’ Broadly acceptable

153. Death as an annual experience Cause of Death chance/year All causes Overall average 55-64 men women 35-44 men women 5-14 boys girls Hang gliding Road accidents Gas explosion (home) Electrocution (home) Lightning 1 in 87 1 in 65 1 in 110 1 in 578 1 in 873 1 in 4,400 1 in 6,250 1 in 670 1 in 10,200 1 in 1 million 1 in 1 million 1 in 10 million

154. Death as an annual experience Cause of Death chance/year Work Accidents deep sea fishing extraction oil / gas construction agriculture all manufacturing 1 in 750 1 in 990 1 in 10,200 1 in 13,500 1 in 53,000

155. Death as a consequence of an activity Activity Chance of death Travel for 100,000 km by motor bike by pedal cycle by car by rail by bus by air Balloon (Atlantic) Pregnancy Anaesthesia 1 in 100 1 in 200 1 in 2,200 1 in 9,000 1 in 22,000 1 in 44,000 1 in 3 1 in 13,000 1 in 25,000

156. Average loss of life expectancy as a consequence of an activity Cause Loss of Life Expectancy (days) Being unmarried (male) Smoker (male) Being unmarried (female) Smoker (female) Dangerous job Vehicle accidents Homicide Average job Medical X rays Coffee drinking Reactor accidents Nuclear industry Smoke alarm Mobile coronary-care units 3,500 2,250 1,600 800 300 207 90 74 6 6 0.2 to 2 0.2 -10 -125

158. Cost-benefit model Cost £ Number of accidents Cost prevention - Employer Cost accidents - Employer Total Costs - Employer ‘ Optimum’ performance - Employer

161. Lay risk estimates

172. League Women voters College students Active club members Experts Nuclear power 1 1 8 20 Motor vehicles 2 5 3 1 Handguns 3 2 1 4 Smoking 4 3 4 2 Motorcycles 5 6 2 6 Alcoholic drinks 6 7 5 3 Private aviation 7 15 11 12 Police work 8 8 7 17 Pesticides 9 4 15 8 Surgery 10 11 9 5 Firefighting 11 10 6 18 Large construction 12 14 13 13 Hunting 13 18 10 23 Spray cans 14 13 23 26 Mountain climbing 15 22 12 29 Bicycles 16 24 14 15 Commercial aviation 17 16 18 16 Electricity (non-nuclr) 18 19 19 9 Swimming 19 30 17 10 Contraceptives 20 9 22 11 Skiing 21 25 16 30 X-rays 22 17 24 7 Football 23 26 21 27 Railroads 24 23 20 19 Food preservatives 25 12 28 14 Food colouring 26 20 30 21 Power mowers 27 28 25 28 Antibiotics 28 21 26 24 Home appliances 29 27 27 22 Vaccinations 30 29 29 25

174. Fragmentiser risk tolerability case study

189. Change Analysis: fall in Victoria Square No recognition of changed circumstances /route Walking/observing on ‘autopilot’ Walking/observing on ‘autopilot’ Attention directed to stall produce Market stalls a significant distraction No unusual ‘distractions’ Also, carrying a shoulder bag and rucksack Pedestrians difficult to navigate around Pedestrians few and no effort to navigate around Diversion necessary from normal route (one step to descend) Frankfurt ‘Christmas’ Market in operation No physical barriers for normal route (and no steps) Anxiety about Course Stress state ‘elevated’ Stress state ‘normal’ Result of dealing with arrangements for AI Course at last minute More preoccupied than usual when going to catch (the) train Preoccupied when going to catch a train Indicates that IP (me) was not walking unduly fast, as was the case Time to get to station 35m Time to get to station 30m Comments Accident situation Normal Situation

190. Change Analysis: fall in Victoria Square - consequences Emergency admission to hospital suffering from whiplash injuries three days later Fall on unseen step, and arrival at station bloody and shaken Delegates at AI course impressed by this Change Analysis! Safe arrival at station Situational violation (need to catch the train) Cancelled ambulance despite police advice (and not given necessary treatment) Accept full first aid treatment Comments Accident situation Normal Situation

197. Accident Scene Warehouse X Racking Victim FLT Offices

198. Fatality due to FLT collision & FLT Collides with person & Victim Dies Person in the FLT Path FLT Fails to Stop Not aware of Need to Stop Aware but unable to Stop Driver actually Ill Driving Too fast Faulty Brakes Not Aware of Person Thinks person will evade 1 Person Aware of FLT Unaware of FLT Thinks FLT will Evade Unable to move out of way Person actually Ill Person Slips/trip Falls Disabled Time too short & Person Did Not See FLT Person Did Not Hear FLT 2 3 Poor visibility Vision obstructed Not looking Reversing Person Conspicuity Poor visibility Vision obstructed Not looking visually impaired FLT Conspicuity Wearing PPE Noisy place FLT quiet Wearing stereo Hearing impaired FLT Accident Investigation

200. Events and Casual Factors General Format Systemic Factors Contributing Factors Systemic factors Contributing factors Secondary events Primary events

204. Runaway Truck ECFA

245. Concluding remarks