Process Safety


A large number of businesses use dangerous substances within their processes and have a duty to demonstrate that they have fully identified and managed the associated risks.  If this applies to you, does your business have an effective basis of safety in place to control risk? 
The development of a Process Safety management system is vitally important in minimizing the risk of equipment failure, fire and explosion, and loss of containment incidents, all of which have the potential to seriously harm human health and/or the environment.  Such incidents can also result in major breaches of legislative compliance, with the potential for significant reputational and financial losses.
Regardless of your business size or specialty, our experienced and approachable team will assist you in identifying and better understanding your site-specific hazards, and evaluating risk, as well as advising on legal responsibilities and best practice control measures to ensure your operational risks are minimized.

NONC can provide:

  • A HAZOP workshop, led by the HAZOP Chair, providing a highly structured and systematic HAZOP study;
  • Use of HAZOP guidewords suitable to the requirements and relevance of the HAZOP study
  • Facilitation of a robust consensus-based decision-making process within the HAZOP Study team, ensuring the important and relevant points are captured;
  • A record of the HAZOP study, through the production of a HAZOP report and/or Actions report, detailing the HAZOP study and any requirements taken away from the HAZOP workshop.
  • Process Hazard Assessment (PHA)
  • Quantitative Risk Assessment (QRA)
  • Layer of Protection Analysis (LOPA)
  • Escape, Evacuation and Rescue Analysis (EERA)
  • Electrical HAZOP (eHAZOP)
  • HAZard study for Escape, Evacuation and Rescue (HAZEER)
  • Consequence Modelling
  • Dropped Object Analysis
  • Environment Identification (ENVID)
  • F&G Mapping Study (FGS)

Process Hazard Assessment (PHA) is a set of organized and systematic assessments of the potential hazards associated with an industrial process. A PHA can provides information intended to assist in making decisions for improving safety and reducing the consequences of unwanted or unplanned releases of hazardous chemicals. A PHA is often directed towards analyzing potential causes and consequences of undesirable events and it focuses on equipment, instrumentation, utilities, human actions, and external factors that might impact the process.

PHA methods are qualitative in nature. The selection of a methodology to use depends on a number of factors, including the complexity of the process, the length of time a process has been in operation and if a PHA has been conducted on the process before, and if the process is unique, or industrially common.

Methods of Process Hazard Assessment
There are a variety of methodologies that can be used to conduct a PHA, including but not limited to:

A checklist used as a hazard evaluation procedure employs prepared lists of questionsrelating to process safety to identify concerns and prompt the analysts to determine whether existing safeguards are adequate. Checklists are used to identify common hazards and ensure compliance with procedures, codes of practice, regulations, etc. Checklist questions are based on experience and knowledge of safety issues for the process and applicable codes, standards and regulations.

Checklists can be applied to virtually any aspect of a process such as equipment, materials, procedures, etc. Their application requires knowledge of the process and its procedures and an understanding of the meaning of the checklist questions. Checklists may become outdated and they should be audited and updated regularly.

The procedure for performing a checklist study is:
  1. Prepare and organize thestudy
  2. Select or generate thechecklist
  3. Perform thestudy
  4. Identify anyrecommendations
  5. Document theresults
  6. Resolve recommendations
  7. Follow -up on recommendations

WI studies involve posing questions relating to initiating events to identify hazardscenarios for a process. The PHA team brainstorms questions in a WI study. The team starts with a prepared list of questions in a WIC study, although almost always additional questions are added as a study proceeds. Sometimes PHA teams develop questions based on the HAZOP thought process by thinking through what questions would arise if a HAZOP study were being performed.

WI methods are well-suited to examining the impacts of proposed changes in Management of Change (MOC) PHA studies because the questions can be tailored to the change and the areas affected by it. They can be used to study virtually any aspect of a process such as equipment, procedures, control systems, management practices, etc. Team leaders should be experienced with the technique since it is provides less structure than other PHA methods.

The procedure for conducting a WI or WIC study is:

  1. Prepare and organize thestudy
  2. Subdivide theprocess
  3. Develop questions
  4. Identify hazards and/or hazardscenarios
  5. Specifyconsequences
  6. Identifysafeguards
  7. Optionally, identifyenablers
  8. Perform riskranking
  9. Identify anyrecommendations
  10. Document theresults
  11. Resolve recommendations
  12. Follow-up onrecommendations

HAZard and OPerability (HAZOP) is a well-known and well documented study. HAZOP is used as part of a Quantitative Risk Assessment (QRA) or as a standalone analysis. HAZOP is a more detailed review technique than HAZID. The purpose of the HAZOP is to investigate how the system or plant deviate from the design intent and create risk for personnel and equipment and operability problems. HAZOP studies have been used with great success within chemical and the petroleum industry to obtain safer, more efficient and more reliable plants. Since HAZOP is based on the assumption that hazards happen because elements of design and operation can deviate from their original intention, its purpose is to reduce risk and ensure the safety of workers in plant environments.

A standard list of seven guide words is used: No, More, Less, As Well As, Part Of, Reverse, and Other Than. The team chooses appropriate parameters for each node, e.g., flow, pressure, temperature, composition, level, addition, cooling, location, etc. The use of guide words with parameters provides the opportunity to explore deviations from design intent in every conceivable way thus helping to ensure completeness of the PHA study.

A HAZOP study primarily assesses the following three parts of a plant function:

  • Step #1: Design
    To assess the design's capability to fulfill its intended function and identify its weaknesses e.g. the composition of the chemical batch reactor.
  • Step #2: Physical Environment
    To assess the environment where the system or design will operate and ensure that it is ideal e.g. is there enough space for the chemical batch reactor to operate as intended?
  • Step #3: Procedure
    To assess the engineered controls such as automation, sequence of steps, human interactions e.g. the steps in producing the target chemical concentration.
The procedure for conducting a HAZOP study is:
  1. Prepare and organize thestudy
  2. Subdivide theprocess
  3. Select process parameters
  4. Specify parameterintention
  5. Generate deviations
  6. Identify causes of deviations
  7. Specifyconsequences
  8. Identifysafeguards
  9. Optionally, identifyenablers
  10. Perform riskranking

HAZardIDentification (HAZID) is a well-known and well documented method. A HAZID is a systematic assessment to identify hazards and problem areas associated with plant, system, operation, design and maintenance. HAZID is used both as part of a Quantitative Risk Assessment (QRA) and as a standalone analysis for i.e. installation, modification, replacement, upgrading, reduction, isolation, lifting.
HAZID (HAZardIDentification) is a high-level, systematic study of process hazards. It is used for early identification of hazards and is typically applied at the conceptual or detailed design stage.
Why Conduct HAZID Studies?

Early identification and assessment of hazards provides critical input for project decisions at a time when design changes have the minimum cost penalty.

Also, a HAZID study provides the basis for a Hazard Register that summarizes the hazards present in a process together with their sources, locations, significance, and controls. The Hazard Register provides a starting point for hazards management and is a regulatory requirement in some jurisdictions.

A typical HAZID study will be conducted this way:
  1. Familiarization with background documentation
  2. Planning of the workshop meeting in a pre-meeting with the customer in order to identify HAZID strategy, division of the system (nodes) and identifying guide words.
  3. Accomplishment of the HAZID review
  4. Documentation of observations
  5. Draft report for client review
  6. Final HAZID report

FMEA is a hazard evaluation procedure in which failure modes of systemcomponents,typically, process equipment, are considered to determine whether existing safeguards are adequate. Failure modes describe how components fail (e.g., open, closed, on,off, leaks, etc.). The effects of each failure mode are the process responses or incident resulting from the component failures, i.e., hazard scenario consequences. A FMEA becomes a FMECA (Failure Modes and Effects and Criticality Analysis) when a criticality ranking is included for each failure mode and effect. A criticality ranking is the same as a risk ranking.

FMEA is used extensively in the aerospace, nuclear, and defense industries. Typically, it is used in the process industries for special applications such as Reliability Centered Maintenance (RCM) programs and the analysis of control systems.

FMEA can be conducted at different levels of resolution. For PHA purposes, usually it is conducted at the equipment level, e.g., valves, pumps, lines, etc. For RCM purposes, usually it is conducted at the equipment component level, e.g., motor, shaft, impeller, casing, seal, bearings, etc. for a pump.

The procedure for conducting a FMEA is:

  1. Prepare and organize thestudy
  2. Subdivide theprocess
  3. List process equipment
  4. Identify equipment failuremodes
  5. Optionally, identify causes of failuremodes
  6. Specify effects(consequences)
  7. Identifysafeguards
  8. Perform riskranking
  9. Identify anyrecommendations
  10. Document theresults

Quantitative Risk Assessment (QRA)
Process Hazard Assessment (PHA) is a set of organized and systematic assessments of the potential hazards associated with an industrial process. A PHA can provides information intended to assist in making decisions for improving safety and reducing the consequences of unwanted or unplanned releases of hazardous chemicals. A PHA is often directed towards analyzing potential causes and consequences of undesirable events and it focuses on equipment, instrumentation, utilities, human actions, and external factors that might impact the process.
PHA methods are qualitative in nature. The selection of a methodology to use depends on a number of factors, including the complexity of the process, the length of time a process has been in operation and if a PHA has been conducted on the process before, and if the process is unique, or industrially common.
Methods of Process Hazard Assessment
There are a variety of methodologies that can be used to conduct a PHA, including but not limited to:

  • Checklist;
  • What if?;
  • Hazard and Operability Study (HAZOP);
  • Hazard Identification (HAZID);
  • Failure Mode and Effects Analysis (FMEA)

Layer of Protection Analysis (LOPA)

A process hazard analysis (PHA), such as a Hazard and Operability Study (HAZOP), is a useful tool in identifying potential hazard scenarios; however, a PHA can only give a qualitative indication of whether sufficient safeguards exist to mitigate the hazards. Layer of Protection Analysis (LOPA) is a risk management technique commonly used in the chemical process industry that can provide a more detailed, semi-quantitative assessment of the risks and layers of protection associated with hazard scenarios.
LOPA allows the safety review team an opportunity to discover weaknesses and strengths in the safety systems used to protect employees, the plant, and the public. LOPA is a means to identify the scenarios that present the most significant risk and determine if the consequences could be reduced by the application of inherently safer design principles. LOPA can also be used to identify the need for safety instrumented systems (SIS) or other protection layers to improve process safety.
LOPA helps the analyst make consistent decisions on the adequacy of existing or proposed layers of protection against an accident scenario. The technique is ideally suited for companies striving to meet specific risk targets or to lower risk as low as reasonably practicable (ALARP).
The overall objectives of the assessment are to determine the following:

  • Whether there are sufficient layers of protection against an accident in place already?
  • Is there a requirement for additional independent layers of protection?

Escape, Evacuation and Rescue Analysis (EERA)

In the event of emergency situations, efficient Escape, Evacuation and Rescue (EER) will be vital to avoid injuries and fatalities. The overall scope for the Escape, Evacuation, and Rescue Analysis (EERA) is to qualitatively examine and evaluate the effectiveness of EER facilities available on site from major accident events which could occur during normal operations (operational phase).
The objectives of the Escape, Evacuation and Rescue Assessment (EERA) study are to:

  • Describe the EER arrangements and facilities for the offshore platform. The proposed EER arrangements cover both the physical means provided for escape, evacuation and rescue, as well as the organizational and procedural measures in place to respond to emergencies
  • Define a set of performance standards and loss of integrity criteria for the EER arrangements
  • Identify and describe a set of major accident hazard events that could potentially affect the ability of personnel to escape or evacuate
  • Define a set of major accident hazard events whose effects the EER facilities should be designed to withstand, with no loss of integrity
  • Define a set of major accident events whose effects could result in the loss of integrity of escape or evacuation facilities (residual risk events)
  • Perform a risk assessment with respect to EER performance standards to show performance criteria can be met
  • If necessary, propose design changes and identify issues for further investigation in order to meet performance criteria
Evaluation of "bottlenecks" in escape routes, which may increase escape times, is a vital part of such analyses.

Electrical HAZOP (eHAZOP) -

HAZOP is a structured multi-disciplinary workshop with the objective of identifying hazards and operability issues in new designs or design modifications. The HAZOP technique is typically applied on process designs in many different industries, such as oil and gas, automotive, nuclear etc.
As for process installations carrying hazardous substances, electrical currents can also be potentially harmful. Furthermore, operability and availability issues are costly since electrical power is often an essential utility for operations. Traditionally, the electrical design is only cross checked by the use of standard design reviews, where the main purpose is to assure that the design of each sub-component is according to applicable standards, laws and regulations. The end user or integrator will have the responsibility to analyze and mitigate possible hazards due to e.g. interface misalignment or package designs not conforming to specifications.
The idea behind an Electrical HAZOP (EHAZOP) is to offer a complement for design reviews as an organized brainstorming with participation from the parties involved in the design and engineering of the electric system together with the suppliers and end user. The methodology is based on IEC 61882 with appropriate guidelines and parameters. A typical strategy is to divide the system into nodes corresponding to the different bus bar voltage levels (e.g. 24V, 110V, 11 kV, etc). The parameters, besides the more typical voltage, current, power, frequency, earthing, etc., shall also involve more typical HAZID parameters with relation to the electric design, such as lightning protection, fire protection, location and housing, etc. The guidewords are usually over, spike, under, dip, offset, fault, segregation, load shedding, blackout, among others, depending on the specific design. ORS will tailor made the EHAZOP to your needs and electric design.
EHAZOP is truly an advantageous tool for custom systems where high level of integration is required. It is a recognized exercise to help minimizing the risk inherently associated with high power installations. ORS experience with EHAZOPs has proven useful to clients for refining their electrical design with safety and operability in mind.

Objectives of a eHAZOP Study are summarized as to-

  • Assess and minimize types of potential hazard presented to personnel in the vicinity of electrical installations.
  • Provide a critical review of both network design and plant to be installed and assess any limitations and their effects on both operability and security of the overall system.
  • Analyze tasks set for operators assess facilities and instructions provided to undertake these tasks and recommend measures to avoid operator error.

eHAZOP is made up of three modules

HAZard study for Escape, Evacuation and rescue (HAZEER) -

Al Hosn GasHAZard study for Escape Evacuationand Rescue (HAZEER)

Background: In 2011, Al Hosn Gas was preparingto take over the management of drilling activitiesfor the Shah Gas Development Programme. Fora new Company, the easiest option would havebeen to adopt and build on existing practices.However, with Al Hosn Gas’ Vision to be “a world-classcompany in the development of sour gasresources and a distinguished partner of choice”,comes a responsibility to seek out opportunitiesfor establishing benchmarks in the managementof HSE in highly sour operations.

An example of how Al Hosn Gas adopts an‘unusual business’ approach is demonstratedin how it develops critical safe systems of worksuch as crisis and emergency response systems.Through intensive stakeholder engagement,Al Hosn Gas implemented a process knownas HAZEER which it uses to accurately identifyfit-for-purpose Crisis and Emergency Responsecontrols as part of its major accident hazardmanagement programme.

Approach: HAZEER is an early step in the Hazardand Effects Management Process (HEMP),providing a systematic and detailed analysis ofeach step of the Escape, Evacuation andRescue (EER) process. HAZEER studiesexamine emergency procedures for majoraccident hazards, and, using bespokeguidewords, identify barriers to the effectiveimplementation of the EER step. The studyresults in an auditable trail with assignedaccountability for decision-making on EERinvestment.

Outcome / Future: The study significantlyreduces the likelihood of emergency systemfailure byidentifying EER-related issues, withemergency plans prepared and necessaryequipment identified in advance, thuspreventing last minute delays. Emergencytraining, drills and exercises are conductedon a “Right First Time” basis, improvingperformance due to greater accuracy earlyin the learning process. Actions are sharedacross assets to identify similar controls andcommon failures.

AlHosn Gas have successfully conductedfurther HAZEER studies on the Shah GasDevelopmentProgramme EPC packages andplan to apply the HAZEER process throughoutthe life of the Shah facilities.

The HAZEER methodology can be appliedacross the complete exploration andproduction value chain preventing majorschedule and cost impacts.

Consequence Modelling -

Consequence Modelling refers to the estimation of the credible physical outcomes of loss of containment scenarios involving flammable, explosive and toxic materials with respect to their potential impact on people, assets, or safety functions.
It is used to predict accident effects and impact on people, the environment and property. The course draws upon loss-of-containment scenarios and guides you through a range of models, using workshops and case studies, to demonstrate different approaches to consequence modelling.
Consequence assessment involves determining the impact to people, plant and surrounding area as a result of:

  • fires and explosions associated with a release of a flammable material, and
  • gas clouds as a result of a release of toxic material.

Consequence assessment also investigates the escalation of these hazards as the initial impact may affect other plant equipment items that may cause further escalation of the initial hazard (e.g. firefighting systems).

Consequence impacts are determined by calculating the extent of the effects of:

  • Pool fires
  • Jet fires
  • Flash fires
  • Vapour cloud explosions
  • Fireballs
  • BLEVEs (boiling-liquid-expanding-vapor-explosion), and
  • Toxic gas releases.

Impact criteria based on thermal radiation, explosion overpressure, chemical toxicity effects etc. are used to determine the potential consequences to people, plant and surrounding environment.

Consequence assessment is also critical at the earlier design stage of a project, as it can be used to assess the adequacy of the proposed control and mitigation measures, optimize the quantity and location of hazardous materials and assist with determining lowest risk design options.

Dropped Object Analysis –

Dropped Object Analysis / Risk Study as part of safety assessment studies is predominantly required to support the design of an onshore and offshore platform. It is to assess the risk involved in the falling object and swinging load impacts during lifting activities in industrial facilities of both onshore and offshore. The focus of the study on impacts to Platforms, structures, process equipment and subsea pipeline.
Dropped objects are significant initiators of incidents in many industries and are substantial contributors to the total risk for offshore and onshore facilities.
Typical Dropped Objects Assessments include:

  • Description of major handling systems and Identification of potential dropped objects.
  • Assessment of dropped object frequencies onto topsides and into the sea using OGP data from pedestal or barge crane lifts
  • Assessment of topsides impact energies and the likelihood of impairing decks or vulnerable equipment
  • Assessment of subsea impact and pipeline annual failure frequency 

The consequences of a falling object include:

  • Personal injury/death;
  • Structural damage;
  • Damage to equipment;
  • Release of hydrocarbons/fire.

Environment Identification (ENVID)
The ENVID specifically looks at the planned impacts of the project on the environment. The workshop examines specific activities, and determines what aspect of the environment could be affected. The ENVID is also concerned with accidental impacts, which are primarily defined in the HAZID.
The purpose of the Environment Identification (ENVID) process is for the early identification of aspects that can potentially impact the environment. Another key element of the process is the identification of proposed measures to prevent, control or mitigate the potential environmental hazards identified. Furthermore, alternative measures and monitoring schemes are provided where necessary.
The major benefit of this process is to provide essential input that may influence the subsequent project design phases. The results are also used to inform the development decision process that is intended to lead to safer and more cost effective design and execution of the operation.

F&G Mapping Study (FGS)
Fire & Gas Mapping studies aim to assess a detector layout against the pre-specified performance targets for detecting a reference flame or gas cloud. Performance targets for specific areas of a facility are generally agreed in advance of the study and aligned with the overall Fire & Gas Safety Philosophy and applicable standards or good practice guides.
FGS typically reduces the magnitude and severity of the consequence instead of eliminating it. Therefore, FGS ineffectiveness is directly related to the inability of the mitigation elements (e.g., fire water system, ventilation system) to perform their functions with a high probability of success.
F&G mapping study is usually conducted to ensure effective design and implementation of the F&G system, which actually plays an important role to prevent the severe consequences from an initial event (e.g. loss of containment).

SIS

NONC offers a full 'cradle to grave' lifecycle service to ensure you meet all of your Functional Safety & SIS (Safety Instrumented System) regulatory responsibilities and can assist you in developing a path towards compliance. It is our aim to make your workplace a safer place.

Safety-Instrumented-System

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