Hazard, Hazid (hazard identification), Hazan (hazard analysis), and Hazop (hazard and operability studies) are important safety and risk management techniques in the steel industry (Fig 1).
Hazard is defined as ‘a condition, an event, or a circumstance that can lead to or contribute to an unplanned or undesirable event’. Hazard is a potential cause to generate a disaster. It has got the potential to cause (i) serious harm to the individual or the environment, (ii) harm, the severity of which depends on the extent and frequency of exposure to the hazard, and (iii) harm that does not usually occur, or is not usually detectable until a significant time (years) after exposure to the known hazard. Any activity, procedure, plant, process, substance, situation or other circumstance that has the potential to cause harm constitutes a hazard.
Hazards are logically classified in the same way as the disaster events are classified. Since a hazard exists because it may result into a disaster, it is usually viewed as natural based, human systems based, or conflict based. Not every hazard results into a disaster, but every disaster is the result of a hazardous condition, whether or not that condition was recognized in advance of the event.
Hazards are normally not identical, not uniform, not exclusive, and not transposable. They are not uniform in their range of occurrence, impacts, or timelines. They have got non identical pattern of development. Hence each hazard is to be understood in the context of its time and place. One hazard generally does not substitute for another, at least at the higher level of classification. Since hazards are not the same, each hazard is to be examined to determine its characteristics in the context of the time and place in which it is likely to impact the organization.
For the characterization of hazards, the following are the key indicators in terms of the situation.
The outcomes of the above key indicators helps in estimating the relative hazard any event poses. The more severe the magnitude of the event or the intensity of impact, the higher is the hazard. Events which can occur at any time of day throughout the year pose a different type of hazard than those that are seasonal or that commonly occur during only part of the day. The individual event in a restricted season may be of catastrophic intensity. The longer the event duration the greater the hazard. It is necessary to consider both the impact and the recovery periods, which may be prolonged for weeks, months, or years. The shorter the timeline for development of the event the higher the hazard.
The wider the area the disaster impacts may cover, the greater the hazard the event poses. The presence of critical facilities in the probable impact zone increases the hazard. This includes facilities necessary for the coordination of disaster response or the operation of emergency teams.
The more often events happen the greater the hazard because of cumulative effects. This is not universally so. In some cases relatively minor events may release energy that may lead to catastrophic failures. Events that are difficult to predict, create a higher hazard because of the lack of reliable signals that protective measures are necessary. Also events that trigger other events or that cause cascading effects are higher in their hazard potential than events that do not typically do so.
Hazid stand for hazard Identification. Steel industry, which is a high risk industry, often requires that all hazards with the potential to cause a major accident are identified.
Hazid is a high level hazard identification technique which is commonly applied on an area by area basis to hazardous installations. Hazid study is the systematic method of identifying hazards to prevent and reduce any adverse impact that could cause injury to personnel, damage or loss of property, environment and production, or become a liability. It is a component of the risk assessment and risk management. It is being used to determine the adverse effects of exposure to hazards and to plan necessary actions to mitigate such risks.
Hazid is one of the best known methodologies to identify potential hazards because it provides a structured approach to identify hazards, potential undesirable consequences, and evaluate the severity and likelihood of what is identified. Hazid involves machine or equipment designers, management and end users, and ensures a full identification of hazards and safeguard procedures in a workplace.
To obtain a list of hazards for subsequent evaluation using other risk assessment techniques. This is sometimes known as ‘failure case selection’.
To perform a qualitative evaluation of the significance of the hazards and the measures for reducing the risks from them. This is sometimes known as ‘hazard assessment’.
Through Hazid, management identifies, in consultation with employees, contractors (as far as is practicable) and safety personnel the following.
The kinds of major accidents that may occur at the plant, the likelihood of a major accident occurring and the likely consequences of a major accident.
Hazid process is to be an ongoing to ensure existing hazards are known, and new hazards are recognized before they are introduced due to the following.
Plant condition monitoring, early warning signals, employee feedback from routine participation in work, and after an incident.
Hazid is a transparent process and is critical to the safety of the plant, equipment, and operating personnel. The benefits of Hazid studies include the following.
Non critical hazards are documented to demonstrate that the events in question could be safely ignored
Hazan is a hazard analysis and is a term used in safety engineering for the logical, systematic examination of an item, process, condition, facility, or system to identify and analyze the source, causes, and consequences of potential or real unexpected events which can occur. A hazard analysis considers system state (e.g. operating environment) as well as failures or malfunctions. Hazan is the identification of undesired events that lead to the materialization of a hazard, the analysis of the mechanisms by which these undesired events could occur, and, usually, the estimation of the consequences. Every hazard analysis consists of the following three steps.
Comparing the results of first two steps with a target or criterion to decide whether or not action to reduce the probability of occurrence or to minimize the consequences is desirable, or whether the hazard can be ignored, at least for the time being.
Hazan is therefore the essential prerequisite for the complete risk assessment process which includes (i) analysis of the hazards, (ii) assessment of the risks which the hazards present, and (iii) determination of ameliorating measures, if any, required to be taken.
Hazan is the first step in the process used for the assessment of the risk. The result of a hazard analysis is the identification of different type of hazards. A hazard is a potential condition which either exists or not exists (probability is 1 or 0). It may in single existence or in combination with other hazards (sometimes called events) and conditions become an actual functional failure or accident (mishap). The way this exactly happens in one particular sequence is called a scenario. This scenario has a probability (between 1 and 0) of occurrence. Often a system has many potential failure scenarios. It also is assigned a classification, based on the worst case severity of the end condition. Risk is the combination of probability and severity. Preliminary risk levels can be provided in the hazard analysis. The main goal of hazan is to provide the best selection of means of controlling or eliminating the risk.
Hazardous Reduces the capability of the system or the operator ability to cope with adverse conditions to the extent that there would be:
(ii) Operators physical distress/excessive workload such that operators cannot be relied upon to perform required tasks accurately or completely
Major Reduces the capability of the system or the operators to cope with adverse operating conditions to the extent that there would be:
Minor Does not significantly reduce system safety. Actions required by operators are well within their capabilities. Include:
Probable Qualitative – Anticipated to occur one or more times during the entire system/operational life of an equipment
Remote Qualitative – Unlikely to occur to each item during its total life. May occur several times in the life of an entire system or group of equipment.
Quantitative – Probability of occurrence per operational hour is less than 0.00001, but greater than 0.0000001
Extremely Remote Qualitative – Not anticipated to occur to each item during its total life. May occur a few times in the life of an entire system or group of equipment.
Quantitative: Probability of occurrence per operational hour is less than 0.0000001, but greater than 0.000000001
Extremely Improbable Qualitative – So unlikely that it is not anticipated to occur during the entire operational life of an entire system or group of equipment
Test interval – The time interval between the testing of a protective system, and its replacement if necessary.
A hazard and operability (Hazop) study is a design review technique used for hazard identification, and for the identification of design deficiencies which may give rise to operability problems. It is a structured and systematic examination of a planned or existing process or operation in order to identify and evaluate problems that may represent risks to personnel or equipment, or prevent efficient operation. Hazop is most commonly applied to systems which transfer or process hazardous substances, or activities where the operations involved can be hazardous and the consequences of failure to control hazards may be significant in terms of damage to life, the environment or property. A hazop study is carried out using a structured approach by an experienced multi-discipline team, facilitated by a hazop leader. The hazop technique is qualitative, and aims to stimulate the imagination of participants to identify potential hazards and operability problems. The relevant international standard calls for team members to display ‘intuition and good judgment’ and for the meetings to be held in ‘a climate of positive thinking and frank discussion’. The hazop technique was initially developed to analyze chemical process systems and mining operation process but has later been extended to other types of systems and also to complex operations such as steel plant operation and to use software to record the deviation and consequence.
Hazop is a structured and systematic technique for system examination and risk management. In particular, Hazop is often used as a technique for identifying potential hazards in a system and identifying operability problems likely to lead to nonconforming products. Hazop is based on a theory that assumes risk events are caused by deviations from design or operating intentions. Identification of such deviations is facilitated by using sets of ‘guide words’ as a systematic list of deviation perspectives. This approach is a unique feature of the Hazop methodology that helps stimulate the imagination of team members when exploring potential deviations.
An inductive risk assessment tool, meaning that it is a ‘bottom-up’ risk identification approach, where success relies on the ability of subject matter experts to predict deviations based on past experiences and general subject matter expertise.
Provide an action list with due dates and identify appropriate person/discipline to progress the action to close out harm. However, risk assessment teams may choose to rate these factors in order to further quantify and prioritize risks if needed.
Hazop is best suited for assessing hazards in facilities, equipment, and processes and is capable of assessing systems from multiple perspectives which include the following.
Design – This includes (i) assessment of system design capability to meet user specifications and safety standards, and (ii) identification of the weaknesses in systems.
Physical and operational environments – It includes assessment of the environment to ensure system is appropriately situated, supported, serviced, contained, etc.
Operational and procedural controls – These includes (i) assessing engineered controls (ex: automation), sequences of operations, procedural controls (ex: human interactions) etc., and (ii) assessing different operational modes such as start-up, standby, normal operation, steady and unsteady states, normal shutdown, emergency shutdown, etc.
Methodology doesn’t force any one to explicitly rate or measure deviation probability of occurrence, severity of impact, or ability to detect
Thanks for sharing, Very useful and worth for construction and operation professional working in risky working environment
Environmental Impact Assessment and Environmental Management Plan for a Steel Project The environment clearance (EC) process for a steel project (Fig 1) has the following built in steps. These steps are (i) screening, (ii) scoping and consideration of alternatives, (iii) baseline data collection, (iv) impact prediction, (v) assessment of alternatives, description of mitigation measures and environmental impact statement, (vi) public hearing, (vii) environment management plan, (viii) decision making, (ix) monitoring of the clearance conditions. Fig 1 Process for obtaining environment clearance for a steel project The environmental impact assessment (EIA) and environmental management plan (EMP) is part of EC process. EIA and EMP is normally necessary for obtaining EC for (i) those projects which can significantly alter the landscape, land use pattern and lead to concentration of working and service population, (ii) those projects which need upstream development activity like assured supply of mineral products supply or downstream industrial process development, (iii) those projects which involve manufacture, handling and use of hazardous materials, and (iv) those projects which are located near ecologically sensitive areas, urban centres, hill resorts, and places of scientific and religious importance. For obtaining EC for the steel project, it is essential that a report covering the EIA and EMP) is submitted to the regulatory authorities. This report assists the process of decision making with regards to the EC for the project. In addition to getting EC for the project, the purpose of the EIA and EMP report is to take into account the environmental aspects of the project not only during its implementation but also after its commissioning. The purpose of EIA is to identify and evaluate the potential impacts (beneficial and adverse) of the steel project on the environmental system. It is a useful tool for decision making based...