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HAZOP analysis

Safe operations with expert HAZOP analysis

The Hazard and Operability (HAZOP) study is the most widely used Process Hazards Analysis (PHA) technique in the chemical, pharmaceutical, food, oil and gas, nuclear, and other process industries worldwide. HAZOP is used during the design stages of a new process or project, for major process modifications, and for periodic review of existing operations. The U.S. Occupational Safety and Health Administration (OSHA), as well as other regulators around the world, recognizes the HAZOP technique as an acceptable methodology for evaluating risk.

The quality and effectiveness of the HAZOP study depends on the leader’s experience with the HAZOP technique, as well as with the process being analyzed, with process-control systems, and with unit operations in general. Our large team of highly-qualified HAZOP leaders and process-safety experts has facilitated numerous HAZOP-based PHA’s worldwide, in virtually all sectors of the process and processing industries.

Hazard and operability (HAZOP) study - Chilworth Technology
Applications of HAZOP analysis

We can facilitate HAZOPs, and other types of PHAs, in English, Spanish, Chinese, French, German, Italian, Arabic, Hindi and other languages. Our worldwide presence helps ensure intimate knowledge of local codes, standards, and cultures. Combined with our expertise in process safety engineering, extensive laboratory and large-scale testing capabilities, interpretation of test results, and ready access to process safety data, our HAZOP capability is unrivalled in our market.

Comprehensive HAZOP studies for sustainable safety

We provide a semi-quantitative HAZOP risk analysis that incorporates the philosophies of Layers of Protection Analysis (LOPA), Safety Instrumented Systems (SIL), and Fault Tree Analysis (FTA). We use these tools to assess the reliability of process controls and number and type of risk reduction measures that might be needed.

HAZOP scenario overview - Chilworth Technology
Overview of a HAZOP scenario

We begin with a review of the available Process Safety Information (PSI) and identification of missing PSI required to support our analysis. The HAZOP study would involve the following procedure:

  • Establishing the “Design Intent” for the process, including the desired and/or safe ranges for each of the operating parameters
  • Applying the Guide Words (No, Less, More, Reverse, etc.) to each of the Process Parameters (Temperature, Pressure, Flow, Level, etc.), to identify deviations from the design intent
  • Determining if the control system and emergency systems are adequate and are sufficiently reliable to prevent each deviation from escalating to an undesirable process incident
  • Estimating the severity of the consequences of each undesired incident. Consequences can be further evaluated using our expertise in consequence modeling with specialist software such as PHAST® and Effects®
  • Estimating the likelihood of occurrence of each undesired incident
  • Utilizing a Risk Matrix to determine the relative risks of the undesired incidents
  • Comparing the risk of occurrence for each incident with corporate guidelines for process risk
  • Determining the number and types of safeguards and/or process improvements that would be needed to reduce the risks to tolerable levels

Our process safety specialist’s report will present the HAZOP team’s recommendations and suggestions for improvements to the process, based on the site’s experience and on recognized and generally-accepted good engineering practices. Following the receipt of comments from the client, a final report is issued.

Tell us about your needs. Speak with a consultant!

Questions and answers about HAZOP analysis

Knowing what to expect before implementing a HAZOP analysis makes for a more successful and efficient process. To that end, here are some frequently asked questions and answers about how our HAZOP studies work.

What is a HAZOP study?

The Hazard and Operability (HAZOP) methodology is a systematic team-based Process Hazards Analysis (PHA) technique that can be used to effectively identify and analyze the risks of potentially hazardous process operations. It is used during the design stages of a new process or project, for major process modifications and for periodic review of existing operations.

What is the purpose and approach of HAZOP?

The purpose of HAZOP is to prevent the release of hazardous materials and energy, followed by mitigation of the consequences should a release occur. It is essential for the team to identify all the hazards of the process being studied, not just the most obvious ones. Our approach is to use a semi-quantitative HAZOP that incorporates Layers of Protection Analysis (LOPA) to assess the reliability and number of safeguards.

What are the advantages of undertaking a HAZOP study?

HAZOP is a rigorous, structured, systematic and comprehensive method, and is adaptable to the majority of process industry operations. It fosters the exchange of knowledge and experience among the participants and enables companies to anticipate potential accidents.

Who takes part in the HAZOP team?

HAZOP is a brainstorming exercise in which individuals from different disciplines participate. It is vital for the HAZOP team to be limited in size (ideally six people or fewer, excluding the HAZOP facilitator and, if there is one, the HAZOP secretary). It is difficult to establish a maximum and minimum number of participants in a HAZOP, since the various functions necessary may be assumed in different ways in different organizations. Nevertheless, and as a very general criterion, it is safe to say that a HAZOP with fewer than three participants (excluding the HAZOP facilitator and secretary) cannot generate sufficient and meaningful discussion.

HAZOP team approach - Chilworth Technology
A typical HAZOP team approach

What information must be gathered in preparation for a HAZOP study?

HAZOP requires a review of all the available Process Safety Information (PSI) as well as identification of any missing PSI necessary for an effective HAZOP analysis. This includes, but may not be limited to:

  • Hazardous materials properties including combustibility, flammability, explosivity, reactivity, self-heating, toxicity, electrostatic properties
  • Process description
  • Process flow sheets
  • Operating procedures
  • Piping and instrumentation drawings (P&IDs)
  • Equipment design specifications
  • Pressure relief systems specifications
  • Site and industry data concerning process-component failure frequencies and probabilities of failure on demand (PFD).

How long does a HAZOP analysis take?

Estimating the duration of a HAZOP is not, of course, an exact science; it requires a good knowledge of the methodology, complexity of the process, nature of the risks that can be identified up front and, of course, the idiosyncrasy of the group. In no case should a HAZOP be carried out without an estimated agenda, but it is not acceptable for the estimation to be rigid and not subject to modification (up or down) as necessary.

What is the end product of the HAZOP study?

At the conclusion of the HAZOP analysis, our process safety specialist will present the observations, findings, and conclusions of the analysis, and preliminary recommendations and suggestions of the HAZOP team to members of the site management. Shortly thereafter, our process safety specialist will submit a written draft report to the client outlining the HAZOP team’s recommendations and suggestions for improvements to the process based on the site’s experience and on recognized and generally-accepted good engineering practices. Following the receipt of comments from the client, a final report will be issued.

What mistakes are commonly encountered when conducting a HAZOP analysis?

Firstly, planning errors can negatively impact the HAZOP study. While an estimated time frame should be in place, lack of flexibility can lead to incomplete analyses. Another pitfall is insufficient, outdated, or missing information. In order to properly identify and address potential hazards, the HAZOP team must have access to timely and complete information. A lack of focus and discipline among team members is also a common problem. Allowing outside calls and interruptions during HAZOP meetings, as well as tardiness or absences hinders the team’s progress. The so-called “minimalist HAZOP” is yet another typical mistake. This refers to superficial studies where key words or parameters are omitted, repetitions are frequent or templates are used, all of which can short-circuit the brainstorming work that allows the team to uncover less obvious risks and hazards. Finally, the “bureaucratic HAZOP” is a subset of the minimalist version. Here the process is reduced to a formulaic box-checking exercise, resulting in repetition and hampering a deeper analysis.

process safety survey

Infographic process safety survey

Participate in the first Global Process Safety Training & Competency Survey that aims to benchmark challenges and trends across industrial sectors and company size. Shine the light on process safety training needs and competence gaps in process industries.

  • What are the biggest process safety training challenges?
  • What are the top leading indicators of process safety performance?
  • What are the biggest competency gaps at organizations?
  • What is driving the themes for process safety competence development?
  • What are the learning methodologies preferred for developing process safety competency?

You will have access to survey results spanning top multinationals from around the globe, and other safety leaders with similar responsibilities and experience in safety.

Together we can improve Process Safety performance in process industries.

TAKE PART IN OUR SURVEY!

Last modified: 20 October 2016

Introduction

We at DEKRA Insight1 respect your privacy and value our relationship with you. This policy describes the types of information we may collect from you or that you may provide when you visit the website www.DEKRA-Insight.com or any other website maintained by the DEKRA Insight family of companies (our "Website"). This policy also describes our practices for collecting, using, maintaining, protecting and disclosing that information.

This policy applies to information we collect:

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1DEKRA Insight is the corporate identity of the following legal entities committed to advancing the cause of safety at work: Behavioral Science Technology, Inc., Behavioural Science Technology International, Chilworth Technology, Inc., Chilworth Technology Ltd., Regulatory Consultants, Inc.; DEKRA Insight Australia Pty Ltd., Optimus Seventh Generation Ltd, BST Consultants Pte Ltd., Safety Consulting Engineers, Inc., BST France SARL, Chilworth Amalthea S.L., Chilworth France SAS, Chilworth Technology Pvt Ltd.

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about chilworth

As the world’s leading one-stop source for industry’s process safety and optimization needs, Chilworth has international consulting bases and laboratory testing facilities with state of the art dust explosion and electrostatic laboratories (with low humidity facility), and a specialist laboratory for the evaluation of thermal runaway reactions.

Chilworth employs a Doctorate Engineering and Scientific staff along with Graduate Engineers, Scientists and Technicians. Our senior consultants are internationally recognized experts in their specialist fields, and many have served on national and international standards committees.

With laboratories and offices in both the Princeton Corporate Plaza (NJ, USA) and the Chilworth Science Park (Southampton, England), our facilities are equipped with fire/explosion hazard evaluation laboratories and a well equipped engineering workshop and instrument fabrication site. Chilworth’s specialist test apparatus includes:

Fire/Explosion Laboratory: 20L sphere, minimum ignition temperature ovens, auto-flammability cells, and adiabatic storage test equipment.

Chemical Reaction Laboratory: Mettler Toledo RC1 Reaction Calorimeter, Adiabatic Dewar Calorimeter, Differential Scanning Calorimeter, Accelerated Rate Calorimeter and Carius Tube

Electrostatics Laboratory: powder resistivity, liquid conductivity, charge decay time and powder chargeability equipment.

Research and Development Laboratory: wide range of analytical and diagnostic equipment.

The client base of Chilworth covers more than 20 countries, and includes manufacturing companies in the fine chemicals/pharmaceuticals, bulk organics, food stuffs, paints, resins/plastics, dyestuffs, pigments, agrochemicals, soaps/detergents, oil/petrochemicals, and the legal and insurance fields.

Bio’s of Chilworth Experts

Vahid Ebadat, Ph.D., M.Inst.P, MIEE, C.Eng., C.Phys. is the Chief Technical Officer of Chilworth and CEO of Chilworth Asia Pacific. He has worked extensively as a process and operational hazards consultant for the chemical, pharmaceutical and food industries. Dr. Ebadat is a regular speaker at training courses on gas and vapor flammability, dust explosions, and controlling electrostatic hazards. He is a member of NFPA 77 Technical Committee on Static Electricity, NFPA 654 Standard for the Prevention of Fire and Dust Explosions from the Manufacturing, Processing, and Handling of Combustible Particular Solids and ASTM E27 Committee on Hazard Potential of Chemicals. Dr. Ebadat’s research has culminated in the publication of numerous technical papers and articles.


Thaddeus C. Speed, physicist and safety professional, is the Senior Technical Engineer for Chilworth Technologies’ explosives testing and analysis division, Safety Consulting Engineers, Inc. Mr. Speed has more than 25 years experience in hazards analysis, process and system safety, and in testing, evaluating and characterizing explosives and other energetic materials. He has published numerous papers on electrostatic discharge safety (ESD), explosives testing methods, ignition and initiation phenomena, in-process classification of energetic materials, and similar topics. B.S. Physics and Astronomy (1984); Certified Safety Professional (1994); approved by the DOT to examine explosives and recommend classifications (per 49 CFR 173.56) (1999).

Mr. Speed’s explosives process hazards and characterization expertise is further enhanced by an in-depth understanding of system safety and the inter-related areas of facility siting, regulatory compliance, process safety management, material characterization and incident analysis. He has developed courses and trained government officials, plant managers, other safety professionals and line operators in various aspects of explosives safety, both as general courses and as tailored training for specific issues, companies and operations.


David E. Kaelin, Sr., B.S.Ch.E., Mr. Kaelin has over 25 years experience in the specialty chemical manufacturing industry and 15 years specializing as a Process Safety Engineer. He has participated in the design and construction of numerous chemical processing facilities and provided support and training in all areas of PSM. As a Process Safety Engineer he has led process hazard analysis, risk assessments and facility siting reviews. At the corporate level he has created and taught courses in PSM and hazard recognition methods.

Mr. Kaelin has led or provided technical assistance to many fire, explosion and runaway reaction incident investigations including incidents involving nitrations, chlorinations, hydrogenations, thermal heat transfer fluids, spontaneous combustion, dust explosions and thermal oxidizer and incinerator operations.

Mr. Kaelin is an expert in the application of hazard recognition techniques including: HAZOP, FMEA. What-If, Fault Tree Analysis, Risk Screening and Checklist. He is an active member of AIChE, and NFPA.


Dr. Swati Umbrajkar, Ph.D. is the Manager of the Chemical Process Evaluation Group. Dr. Umbrajkar received her Doctorate from the New Jersey Institute of Technology. Her research interests include the synthesis of metal/metal oxide nanocomposites; analysis of highly energetic materials using X-ray diffraction, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and a number of post analysis techniques to characterize the thermodynamic and kinetic parameters of a test system.

Dr. Umbrajkar consults with clients on a variety of process safety issues including but not limited to high-pressure DSC cell tests, adiabatic calorimetry (ARC and ADC), reaction calorimetry (RC-1), all of which allow for the safe scale-up of batch and semi-batch processes. She has expertise in determining self-acceleration decomposition temperature (SADT) and time to maximum rate (TMR), which are critical issues associated with the storage of bulk materials. As the Manager and Consultant in the Chemical Process Evaluations Laboratory, she is proficient in the interpretation of data for a wide variety of process safety scenarios. She has authored several articles in the fields of, ‘Synthesis and Analysis of Highly Energetic Materials’ and ‘Chemical Process Safety’.

She received the Excellence Award from NASA for her services in NASA’s SHARP student program in 2005 and Research Experience for Undergraduate (REU) students at the New Jersey Center for Engineered Particulates (NJCEP) in 2006. She was awarded the Best Graduate Student Research Overall presented at the Graduate Student Research Day on November 6, 2006. She is also the recipient of the ‘best presenter’ award at the AIAA (American Institute of Aeronautics and Astronautics) Young Professionals in Science and Engineering Conference (Northeast Section) in November 2006. She is a member of the American Institute of Chemical Engineers.


Richard W. Prugh, M.S.Ch.E., CSP, PE, Mr. Prugh is a Senior Process Safety Specialist at Chilworth and provides process safety engineering expertise to clients at large and small plants, to improve the safety of chemical manufacturing operations. During his career with the Du Pont Company, he was involved in instrument engineering, explosion-hazards testing, explosives manufacturing and testing, pilot-plant supervision, organic-chemicals research, safety and fire protection audits, and process-safety consulting. Since 1985, he has provided process safety services to chemical and petrochemical plants in thirty-two Statest and in twelve foreign countries. He is the author of “Guidelines for Vapor Release Mitigation” and 25 presentations to Loss Prevention Symposia, and he prepared the “Toxicity” section for the 2008 issue of “Perry’s Chemical Engineers’ Handbook” and the “Safety” sections for three encyclopedias. His recent experience involved overseeing the safety analyses of nerve-gas destruction plants and auditing the safety status of a dozen off-shore installations, including evaluation of management and employee safety culture.


Vladimir Stetsovsky, M.S., is a Senior Process Safety Specialist with over 19 years experience in the manufacturing industry and utilities, and 7 years specializing as an Electrostatic Safety Engineer. His career involved converting and specialty chemical manufacturing with numerous hazardous chemicals in both batch and continuous operations. He has participated in the design and construction of several large chemical and converting processing facilities and provided support and training in all areas of Process Electrostatic Safety Management. As an Electrical Engineer he has led process hazard analysis, risk assessments and facility siting reviews. At the corporate level he has created installation specifications and taught courses in ESD and hazard recognition methods and provided technical safety support to manufacturing sites producing adhesives and pressure sensitive products.

Mr. Stetsovsky has led or provided technical assistance to many fire and explosion incident investigations including incidents involving thermal heat transfer fluids, spontaneous combustion, dust explosions and thermal oxidizer and incinerator operations. In these investigations he has provided valuable insight into the root cause and made practical suggestions for eliminating or controlling the identified hazards.


Steven J. Luzik PE, CFEI, is a Senior Process Safety Specialist at Chilworth Technology, Inc. with over 30 years experience in the area of fire and explosion hazards including gas/vapor explosions, dust explosions and fire and explosion protection strategies. He graduated from the University of Notre Dame with a BS degree in Chemical Engineering. He is a registered Professional Engineer in the State of Pennsylvania and a Certified Fire and Explosion Investigator (CFEI) with the National Association of Fire Investigators (NAFI). As a former Mine Safety and Health Administration [MSHA] manager and technical specialist, he has investigated a multitude of incidents involving flammable vapors, gases and dusts that have included surface and underground mining facilities and industrial facilities where fires and explosions have occurred. He has conducted dust explosion hazard assessment at several coal-fired power plants.

He also has served as a moderator of a flammability and dust explosibility laboratory, processing requests from MSHA and other Federal agencies for testing to determine the flammability and explosibility properties of solids, liquids, dusts and vapors. In this capacity, he has been called upon to provide expert testimony on the explosibility hazards associated with the manufacturing, processing and handling of these materials. He is a member of the American Society for testing and Materials (ASTM) E-27 Committee on Hazardous Properties of Chemicals, the National Association of Fire Investigators (NAFI) and the National fire Protection Association (NFPA). He has authored numerous publications in the areas of fire and explosion prevention, protection and investigation.


David Y. Kohn, B.S. Ch., is a Chemist at Chilworth He has 8 years of experience in process safety testing, scale-up, optimization, transportation (UN/DOT regulations) and thermal runaway reactions. As a Chemist in the Chemical Reaction Hazards Laboratory, he is proficient in the performance of tests using RC1, ARC, Adiabatic Dewar and Carius Tube; he is skilled in a variety of transportation and storage testing; and he is experienced in the interpretation of data for process safety. He has co-authored papers on such topics as process safety and thermal instability of reactions. David has been a member of the American Chemical Society since 1996.


Robert L. Gaither, CSP, Ph.D., is a Senior Process Safety Specialist for Chilworth. Dr. Gaither has more than 28 years’ experience in company operations, regulatory compliance, management consulting, and process safety/risk management experience. He has led organizations at site, division and corporate levels to achieve record safety performance, significant cost savings, and external / internal recognition for accomplishments.

Dr. Gaither has proven leadership and interpersonal skills that enable customers to discover synergies for business excellence. His keys to successes are working effectively with all organizational levels, strong communication skills, assessing customer/business partner needs and finding solutions, mentoring staff, promoting teamwork, and leveraging systems and resources already in place.

Dr. Gaither is a trained expert in HAZOP and SIL/LOPA Facilitation; and Chevron RISKMAN2 / IHAZID Process. He is also a trained and experienced PHAST User.


Pieter Zeeuwen, M. Sc., is a Senior Process Safety Specialist at Chilworth. He has more than 30 years experience in the gas and dust explosion fields, including materials testing, small and large scale explosion research, and consultancy for industry and government agencies in number of countries. His areas of expertise include gas and dust explosion hazard assessment, gas and dust explosion prevention and protection, electrostatic hazard assessment, hazardous area classification, and gas cloud explosions as well as incident investigations.

Over the years, Mr. Zeeuwen has served on many working groups including various Standards committees, both nationally and internationally, e.g. most recently CEN (European Standards Committee) working groups on explosion protection methods and on test methods. He regularly lectures on various aspects of explosion safety and acts as seminar chairman and course director. Mr Zeeuwen has published numerous articles in scientific journals and presented many papers at international conferences.


Craig S. Rudenstein, P.E., M.S. Eng Mgt., B.S.Ch.E., Sr. Process Safety Specialist for Chilworth Technology, Inc. Mr. Rudenstein is a licensed Professional Chemical Engineer with over 35 years experience and education in Process Safety, Employee Safety, Environmental Compliance, Process Engineering, Project Management, Energy, and Quality Management Systems. For 25 years he has developed expertise in facilitating and managing PHA studies using methodologies of HAZOP, What-If, Checklist, FMEA and LOPA for specialty chemicals, pharmaceuticals, foods, and petrochemicals industries. He is experienced in new PHA’s, design- stage or preliminary hazard reviews, and PHA revalidations as well as consequence screening modeling. He possesses a full understanding of regulatory requirements and how to incorporate site- specific work practices, policies and procedures into PSM and RMP compliance programs. Mr. Rudenstein has led numerous regulatory compliance audits and process safety management assessments. Mr. Rudenstein is an experienced trainer for process safety management topics. He has led Incident Investigations involving witness interviews and application of factual tree analysis, reviewed by enterprise management and legal counsel. Mr. Rudenstein is a Senior Member of AIChE.


Lisa C. Hutto, B.Sc., MBA, SIIRSM, is a Senior Process Safety Specialist at Chilworth Technology, Inc. with 20 years of HSE&S experience in manufacturing, chemical and oil and gas industries with 11 of the years specializing in Process Safety Management. She has an extensive background in health, safety, environmental and security, to include the reduction of incident rates, reduced emissions by implementing new projects, facility security development, as well as being the driver for supporting business and HSE objectives. Her PSM experience include implementing and developing new Process Safety Management programs, PSM Audits and Gap Analysis, establishing management of change programs, developing procedures for all 14 elements of PSM, emergency response plan development and leading Process Hazards Analysis for oil and gas, chemical and manufacturing companies. She also has a strong background of upstream and downstream oil & gas experience, to include work on the North Slope of Alaska, with multiple oil & gas companies.


Walter S. Kessler, B.S.Ch.E., Mr. Kessler has 20 years experience in the refinery, gas processing, specialty chemical, pharmaceutical, manufacturing, and HVACR (Heating, Venting, Air Conditioning and Refrigeration) industries, including 5 years experience performing Process Safety Engineering functions. He was instrumental in the design and construction of several refinery, gas and chemical processing facilities, designing a pharmaceutical filling process, improving several manufacturing processes, and also has experience in six sigma and lean manufacturing. He has been involved in HAZOPS on new and existing facilities, developing and designing DCS and SIS control systems and the associated cause and effect charts, process safety reviews, and developing and implementing various stages of the 14 elements of the PSM program in facilities. He has a very safety conscious attitude and perspective and has even trained with and been actively involved in chemical plant ERT teams.

Laboratory Testing

lab testing

We operate one of DEKRA's world premier chemical process hazards laboratories. Process safety testing is used to develop the data on which fire and explosion hazard assessments and incident investigations should be based.

Learn about our Laboratory Testing options