Hazard Assessment and Risk Management Techniques for Industries

Hazard Assessment and Risk Management Techniques for Industries Prepared by : VIJAY ASAR Chief Co-ordinator, DPMC Disaster Prevention & Management Centre Fire Station, GIDC, Ankleshwar- 2 disasterm@dataone. in dpmcank@sancharnet. in Ph. No. – (02646) 220229, 653101

Disaster Risk Management l The systematic process of using administrative decisions, organisation, operational skills and capacities to implement policies, strategies and coping capacities of the societies and communities to lessen the impacts of environmental and technological disasters.

Disaster Risk Reduction l The conceptual framework of elements considered with the possibilities to minimize vulnerabilitiies and disaster risk throughout a society, to avoid (prevention) or to limit (mitigation and preparedness) the adverse impacts of hazards.

What is system safety? The system safety concept is the application of special technical and managerial skills to the systematic, forward-looking identification and control of hazards throughout the life cycle of a project, program, or activity. The concept calls for safety analyses and hazard control actions, beginning with the conceptual phase of a system and continuing through the design, production, testing, use, and disposal phases, until the activity is retired.

Chemical hazards Type of chemical hazards v Material hazard : Hazardous nature of chemicals like Inflammable, explosive, toxic, corrosive, reactive, radioactive, reducing, oxidizing, decomposing or incompatible. v Process hazards : In process, chemical and physical change, chemical reaction, pressure, temperature, level, flow, quantity and other parameters create. v Vessel hazards : The vessels and equipments in which the chemicals are stored, handled or reacted pose.

Chemical hazards Type of chemical hazards v Control hazards : The inadequate, defective, under design or wrongly modified control devices or their of failure cause. v Fire hazards : Fire or explosion v Toxic hazards : Affluent disposal and gaseous emissions bring pollution and toxic hazards. v Handling hazards : Leaks, spills and splashes cause.

Chemical hazards Physical hazards or health hazards v Physical Hazards : Corrosives, Explosives etc. v Health Hazards : Toxic, Irritants and Oxides. Accident an emergency hazard v Absence, nonuse or failure of fire fighting equipments, personal protective equipments, emergency control devices

The Hazard A potential condition or set of conditions, either internal and/or external to a system, product, facility, or operation. Which, when activated transforms the hazard into a series of events that culminate in loss (an accident). A simpler and more fundamental definition of hazard is a condition that can cause injury or death, damage to or loss of equipment or property, or environmental harm.

Hazard Analysis at various stages of Project Execution

Process Hazard Management includes: v Hazard identification. v Hazard Assessment. v Accidental vapour cloud release (flammable and/or toxic). v Engineering approaches to mitigation. v Design features for emergency control. v Process Safety Management (PSM). v Planning for counter measures. v Emergency response planning (ERP-onsite). v Alerting local authorities and public.

Process Hazard Management Some important elements of PSM. : v Employee Participation v Process Safety Information (PSI) v Process Hazard Analysis (PHA) v Operating Procedure v Training v Contractor Safety v Pre-Startup Safety Review v Mechanical Integrity v Hot Work Program v Management of Change (MOC) v Incident Investigation v Emergency Planning & Response Compliance Audits

Process Hazard Management 1. Operating Procedures v Initial startup v Normal, temporary & emergency operations v Normal shutdown v Startup following a turnaround or after an emergency shutdown v Operating limits v Consequences of deviation steps required to correct or to avoid such deviation

Process Hazard Management 1. Operating Procedures v Safety & Health considerations v Precautions necessary to prevent exposure, including engineering controls v Administrative controls & personal protective equipment v Controls measure to be taken if physical contact or airborne exposure occurs v Quality control for raw materials & control of hazardous chemical inventory levels v Safety systems & their functions.

Process Hazard Management 2. Pre-Startup Safety Review v Construction & equipment is in accordance with design specifications v Safety, operating, maintenance & emergency procedures are in place & are adequate v Modified facilities meet the requirements contained in Management of Change v Training of each employee involved in operating a process has been completed.

Process Hazard Management 3. Management of Change (MOC) v The technical basis for the proposed v v v change Impact of change on safety and health Modifications to operating procedures Necessary time period for the change Authorization requirements for the proposed change Up-date of Process Safety information (PSI), PHA & Operating procedures.

Process Hazard Management 4. Process Hazard Analysis (PHA) v Engineering & administrative controls v Detection v v methods for providing early warning of releases Consequences of failure of engineering and administrative controls Facility site Human factors Qualitative evaluation of a range of the possible safety and health effects of failure of controls on employees and others

HAZID Technique HAZID is an automated hazard identification tool for continuous process plants and principle features of v Sectionalizing the process plant into several units v Generation of hazardous incident scenarios v Use of models to distinguish between the feasible and infeasible scenarios v Use rules to detect plant configuration problem.

HAZID Technique HAZID Process Divide the Process Plant into smaller section Generate Hazardous Incident Scenarios Identify the feasible Scenarios only Identify plant configuration problem Generate output in HAZOP table

The Hazard severity Category I Name Catastrophic II Critical III Marginal IV Negligible Characteristics Death Loss of system Severe injury or morbidity Major damage to system Minor injury or morbidity Minor damage to system No injury or morbidity No damage to system

The Hazard Possible hazard likelihood Description Leve Specific Individual Item l Fleet or Inventory Frequent A Likely to occur frequently Continuously experienced Probable B Will occur several times in life of an item Will occur frequently Occasional C Likely to occur sometime in life of an item Will occur several times Remote D Unlikely but possible to occur in life of an item Unlikely but can reasonably be expected to occur improbable E So unlikely, it can be assumed occurrence may not be experienced Unlikely to occur, but possible

The Hazard Assessment Matrix HAZARD CATEGORIES Frequency of Occurrence I Catastrophic II Critical III Marginal IV Negligible (A) Frequent 1 A 2 A 3 A 4 A (B) Probable 1 B 2 B 3 B 4 B (C) Occasional 1 C 2 C 3 C 4 C (D) Remote 1 D 2 D 3 D 4 D (E) improbable 1 D 2 E 3 E 4 E

The Hazard Assessment Matrix Hazard Risk Index HRI 1 A, 1 B, 1 C, 2 A, 2 B, 3 A I 1 D, 2 C, 2 D, 3 B, 3 C II 1 E, 2 E, 3 E, 4 A, 4 B III 4 C, 4 D, 4 E IV Suggested Criteria Unacceptable Undesirable (Management decision required) Acceptable with review by management Acceptable without review

The Hazard Relationship of qualitative probability ranking to quantitative values Description Level Frequency of occurrence Potential relationship to Quantitative Value Frequent A High 10 -1 Probable B Occasional C Medium > 10 -3 Remote D > 10 -4 Improbable E Low > 10 -6

The Concept of Risk: ”Chances or possibility of accidental losses or undesired consequences. " v The probability of a dangerous event posed by a hazard, over a definite time period of exposure or v The frequency at which such events will occur and results in fatalities to certain number of people and v The consequence of such events in terms of expected number of fatalities per year. Risk = (Probability) x (Consequences)

Consequence Analysis or Semi Quantitative Risk Analysis l Assessment of possibilities --- By use of various hazard identification techniques like * Preliminary Hazard Analysis (PHA) * Hazard & Operability Study * Safety Audit * Fault tre analysis * Event tree analysis, etc.

EFFECT MODELS l Conceiving a credible scenario by hazard identification techniques Computation of physical effects of the scenario by suitable models like: -- Outflow model -- Dispersion model -- Unconfined vapour cloud explosion models -- Jet fire dimensions -- Damage from shock wave on BLEVE -- Fire ball radiation damages -- Pool fire radiation damages etc. •

TECHNIQUES AVAILABLE o Fire & Explosion Index (Dow Index) and Toxicity Index o Calculation of damages likely from the fires, explosions and toxic releases and combining the damages with probabilities of occurrence in terms of Individual Risk and Societal Risk. ( The later is more objective for estimating the distances likely to be affected)

The Mathematical Models Available to Compute the Effects -- Release rate of liquids under pressure. -- Distance of Lower Explosive Limit in the windward direction. -- Contours of LEL concentrations at the ground level. -- Mass of gas within explosive range (For unconfined vapour cloud) -- Shockwave damage on ignition of unconfined vapour cloud explosion. -- Mass of gas in explosive range on BLEVE. -- Fire Ball Radius. -- Fire ball duration. -- Radiative flux. -- Thermal Dose.

Dow and Mond Indices Both the methods are closely related and as such Mond Index was developed as an extension of DOW index. Primarily, Dow index calculates the Fire & Explosion index for a process unit taking into consideration the flammability and reactivity of the material handled in the process units under the general and special process condition. Mond Index on the other hand uses specifically the material toxicity in addition to the other aspects.

Dow and Mond Indices Fire & Explosion index : (F & E 1) = MF x (GPH) (SPH) Toxicity Index : Th + Ts (1+GPH+SPH) 100 Where, MF SPH GPH Th Ts = Material Factor = Special Process Hazard = General Process Hazard = Toxicity factor based on the NFPA hazard index (0 – 4) = Correction factor (additional penalty) for toxicity based on Maximum Allowable Concentration (MAC) value in ppm

Dow and Mond Indices Toxicity Factors and Correction Factor for MAC values NFPA Index Number Toxicity Factory (Th) 0 0 1 50 2 125 3 250 4 325 MAC (in ppm) TS 5 and blow 125 Between 5 and 50 75 50 and more 50

Process Hazard Management General Process Hazard (GPH) GPH includes processes e. g. exothermic reaction, endothermic reactions, hydrogenation, alkylation, isomerisation, sulphurization, neutralization, esterification, oxidation, polymerization, condensation, halogenation, nitration, loadingunloading operation, enclosed process units, inadequate drainage and proper access etc. different penalties are assigned for different processes.

Process Hazard Management Special Process Hazard (SPH) SPH includes special hazards posed due to process parameters like temp. , pressure, flammability ranges (UEL, LEL) of material and issues like internal and external corrosion, leakage from joints etc. additional penalties are assigned for special process hazards. Selection of the process units which may contribute to a fire or explosion or toxic release

Process Hazard Management The material factor which are the functions of flammable and reactivity can be calculated by the following way ; v Find out flash point of a material or HCV by multiplying heat of combustion by the vapour pressure of that substance at 27’ C. v Find out flammability factor from the next table from the flash point data or HCV value. v Find out the adiabatic decomposition temp. of the substance. v Find out the reactivity factor from the table from decomposition temp. value.

Dow and Mond Indices Table for finding out Material Factor (Mf) from the table Calculate Mf from following Table from Left to Right Decomposition temp. Td Deg K Flash HCV Pt. k. J bar/ mol F L None < 4 x 10 -5 A >100 4 x 10 -5 2. 5 40 -100 < 830 935 1010 1080 > 1080 Reactivity ………………… 0 1 2 3 4 0 0 14 24 29 40 M 1 4 14 24 29 40 2. 5 - 40 A 2 10 14 24 29 40 20 -40 40 – 600 B 3 16 16 24 29 40 < -20 > 600 I 4 21 21 24 29 40 L ITY Material Factor MF

Procedure for Calculating the Indices v v Identify the most process units for risk point of view. Determine the material factor (MF) for each process units (flammability & reactivity of material) Determine the Fire & Explosion Index (F&EI) and the problem exposure area for each process unit from the formula. Calculate the Maximum Probable Property Damage (MPPD).

Indices and the Extent of Hazard F & E index Toxicity Index Degree of Hazard 1 – 60 1– 6 Light 61 – 96 6 – 10 Moderate 97 – 127 > 10 Intermediate 128 – 158 > 10 Heavy > 159 > 10 Severe

Risk Analysis General Principles of Risk Analysis 1. All relevant risks are systematically addressed Identify major, don’t concentrate on minor Consider those aspects of work which are hazardous Take into account & critically assess existing safety controls & measures provided 2. Address what actually happens Actual practice, not instruction Consider non-routine operations Pay attention to changes/interruptions

Risk Analysis General Principles of Risk Analysis 3. Include all who could be affected, including visitors, contractors, and general public 4. Take into account, and objectively assess, control measures 5. The level of protection measures should match the level of risk (i. e. risk within the ALARP region) 6. In most cases, make a rough assessment first, find out the need for detailed assessment and carry out the same, if needed.

Risk Analysis Use of Probabilities in Risk Analysis The risk of operational activity with hazardous materials consists of two elements The consequence of certain unwanted event The probability of certain consequences that will occur A distinction is made between 3 types of probabilities The probability of the initiating event. The probability that designed counter measures may function The probability of certain consequences of an accident

Risk Analysis Layers of Protection Analysis Offsite Emergency Measures Community Alerting & Evacuation, if necessary Onsite Emergency Measures Onsite Evacuation Protective Measures & Control Safety Instrumented Mitigation Protective Control & Monitoring Process alarms & Safety Instrumented Control Process Control & Supervision Hazardous Process

Nomogram of Risk Assessment P X S R

Risk Analysis Consequence BLEVE Model for Different Static and Mobile Pressure Vessels BLEVE Scenarios and Consequence Distances Storage type Inventory (MT) 100% fatality Distance 1% Fatality Distance Road tanker 12 137 M 500 M --Do--- 20 162 M 600 M Rail Wagon 50 218 M 700 M Horton Sphere 140 305 M 940 M ---Do--- 1150 624 M 1834 M

Consequence Analysis for a Ammonia Tank Leak Scenario : 20” dia. Tank having leak of NH 3 from 10” pipe Consequence : Distance to IDLH is 8. 9 Km Kilometer 4 2 0 2 6 4 Kilometer 8 10

Consequence Analysis Sour (containing H 2 S) Natural Gas pipeline leak scenario Scenario : full bore rupture of a 42” pipeline Consequence : Distance to IDLH is 3. 9 Km Kilometer 1. 5 0 0. 5 1 0 1 2 Kilometer 3 4

Risk Analysis Risk control techniques / Risk Management v Inherent safe design (built-in safety) v Fault tolerant measures (single or multiple v v v failures) Protective measures Adequate information on the residual risk Administration controls (e. g. allocation of task to the human operator, training etc. ) Other Risk Reduction measures Corrective and preventive actions Document control

Risk Analysis List of Software's Available for Risk Analysis and Other Studies Sl. No. Item Description Application 1. SAFETI Onshore Risk Analysis. 2. SFU Offshore Risk Analysis. 3. CAFTAN Fault Tree Analysis. 4. ETRA Event Tree Analysis. 5. HAZSEC. HAZOP Study. 6. HAZTRAC. HAZOP Recommendation Tracking. 7. PHAST. Consequence Analysis. 8. WHAZAN Consequence Analysis.

Risk Analysis List of Software's Available for Risk Analysis and Other Studies Sl. No. 9. Item Description EFFECTS. Application Consequence (Effects) Modeling. 10. DAMAGE Consequence (Damage) Modeling. 11. PC-FACTS. Failure & Accident Databank. 12. ASAP Event Tree Analysis. 13. FMECA Failure Mode Effects & Criticality Analysis. 14. ANEX Life Time Analysis & Failure Estimation. 15. E&P FORUM Hydrocarbon Leak & Ignition Database. 16. ALOHA Consequence Analysis

Risk Analysis List of Software's Available for Risk Analysis and Other Studies Sl. No. Item Description Application 17. CLASS Hazardous Area Risk & Classifications 18. RISK CURVES TNO Individual & Group Risk computations 19. RISKA T Risk Analysis model of Health & Safety Executives, UK 20. FACTS TNO Frequency Estimation Database 21. OREDA DNV Frequency Estimation Database 22. FRED Consequence Analysis software of Shell, UK 23. EAHAP Consequence modeling software of Energy Analysts Inc. US)

Risk Communication Seven Cardinal Rules 1. 2. 3. 4. 5. 6. 7. Accept and involve the public as a legitimate partner. Plan carefully and evaluate your efforts. Listen to the public’s specific concerns (Communication is two way activity) Be honest, frank and open (Trust and credibility are most precious assets) Coordinate and collaborate with other credible sources Meet the needs of Media ( provide risk information tailored to the needs of each type of media) Speak clearly and with compassion ( Use simple non technical language with general public)

Have a Healthy Life In Safe Environment. DISASTER PREVENTION & MGMT. CENTRE Ankl. ESHwar.