Hazard identification study

Before any mitigation measures can be designed, an effective hazard identification study must be conducted. The results of such a study (a set of release scenarios) can be used to develop a coherent set of mitigation strategies. In the process industries, these studies are most commonly conducted using hazard and operability (HAZOP) studies, what-if checklists, failure modes and effects analyses (FMEA), and several other comparable techniques (CCPS, 1992). 

Percutaneous absorption studies utilizing rhesus monkeys have one Important single advantage. That is, their skin type and absorption characteristics seem to be similar to humans. This is of utmost concern since the purpose of this study is to simulate the human case. This is not a toxicology study, and it should not be the purpose of this study to estimate a worst case scenario as in a hazard identification study. Thus, in spite of the many shortcomings of the described procedures, monkey percutaneous absorption studies could play an important role in pesticide risk assessments. 

Conducting hazard identification studies (HAZIDs), hazard and operability analyses... 

The initial hazard identification studies identify a total of 76 hazard categories, broken down by stakeholder affected. To aid in the development of taxonomies, the framework of Manuj Mentzer (2008) was used as a foundation. However, given the preliminary nature of these results, it is likely that these will be restructured. 

Over the years there have been several comprehensive hazard identification studies carried out on railway systems in the UK that could be utilised to avoid the need for further detailed hazard identification assessments. It has, however, still been necessary to develop a full list of hazardous events and their associated precursors for inclusion in the SRM. 

Traditionally, hazard identification has considered whether fatalities or injuries to people occur as a result of equipment, system or procedural failures. However, to ensure that all possible events leading to fatalities or injuries were identified for inclusion in the SRM, in addition to referencing the existing hazard identification studies it was decided to consider the hazards using a novel approach whereby the generic injury mechanisms by which a person can be killed or injured are identified. The question was then asked how can this type of injury be caused on a railway system ... 

In order to give confidence in the completeness of the hazardous events identification process, the derived list of hazardous events was cross-checked against the previous hazard identification studies undertaken on the UK railways. 

Existing hazard identification studies were also used to identify and extract the precursors and the control measures and mitigation factors which are applicable to each hazardous event. This information forms the basis of the development of the SRM for each hazardous event. 

Hazard Identification Studies (HAZID) Safety and Risk Management Services Germanischer Lloyd — Services/Product Description. 

This book concerns functional safety assessment and Figure 1.5 illustrates how HAZOP and HAZID (Hazard Identification) studies provide the trigger for the functional safety assessment of plant and items of mitigation (ie safety related systems). 

Extensive and systematic hazard identification has been carried out based on the description of the system and the operational environment (Ludc, 2003b). All of the hazards identified during the hazard identification study have been analysed, stmctured and mapped to the Core Hazards (higher level hazard groupings) originating from the Axle Counter Concept Safety Case, which aims to support the development of Cause-Consequence models for the project. 

What is the change (Confirm correctness of information in the Hazard Identification Study Briefing Document)... 

Most hazard identification procedures have the capabiUty of providing information related to the scenario. This includes the safety review, what-if analysis, hazard and operabiUty studies (HAZOP), failure modes and effects analysis (FMEA), and fault tree analysis. Using these procedures is the best approach to identifying these scenarios. 

Fire and Explosion Index (Ffrom fires and explosions. frequency The rate at which observed or predicted events occur. HAZOP HAZOP stands for hazard and operabihty studies. This is a set of formal hazard identification and ehmination procedures designed to identify hazards to people, process plants, and the environment. See subsequent sections for a more complete description. 

The cost of performing the hazard identification step depends on the size of the problem and the specific techniques used. Techniques such as brainstorming, what-if analyses, or checklists tend to be less expensive than other more structured methods. Hazard and operability (HAZOP) analyses and failure modes and effects analyses (FMEAs) involve many people and tend to be more expensive. But, you can have greater confidence in the exhaustiveness of HAZOP and FMEA techniques—their rigorous approach helps ensure completeness. However, no technique can guarantee that all hazards or potential accidents have been identified. Figure 8 is an example of the hazards identified in a HAZOP study. Hazard identification can require from 10% to 25% of the total effort in a QRA study. 

Hazard identification through animal experiments, epidemiological studies, or structure activity analyses... 

Hazard identification, step one, means identification of new chemicals or other factors that may cause harmful health effects. Previously, novel hazards were usually observed in case studies or after accidents or other excessive exposures, usually in occupational environments. Today, thorough toxicity studies are required on all pesticides, food additives, and drugs. New chemicals also have to be studied for their potential toxic effects. Thus, earlier hazards were in most cases identified after they had caused harmful effects in humans. Today, most chemical products have been evaluated for their toxicity with experimental animals. Therefore, hazard identification has become a preventive procedure based on safety studies conducted before a chemical compound or product reaches the market, and before individuals are exposed to it. ... 

An opportimity for error recovery would have been to implement a checking stage by a supervisor or independent worker, since this was a critical maintenance operation. However, this had not been done. Another aspect of the unforgiving environment was the vulnerability of the system to a single human error. The fact that the critical water jacket flow was dependent upon a single pump was a poor design that would have been detected if a hazard identification technique such as a hazard and operability study (HAZOP) had been used to assess the design. 

All of these factors determine the stress experienced by the workers and the extent to which operational errors will be recovered before disastrous consequences have ensued. In this context, hazard identification techniques, such as hazard and operability studies (HAZOP), failure modes and effects and criticality analysis (FMECA), fault trees, and others are useful in making the process environment more forgiving. 

In this study detailed fault trees with probability and failure rate calculations were generated for the events (1) Fatality due to Explosion, Fire, Toxic Release or Asphyxiation at the Process Development Unit (PDU) Coal Gasification Process and (2) Loss of Availability of the PDU. The fault trees for the PDU were synthesized by Design Sciences, Inc., and then subjected to multiple reviews by Combustion Engineering. The steps involved in hazard identification and evaluation, fault tree generation, probability assessment, and design alteration are presented in the main body of this report. The fault trees, cut sets, failure rate data and unavailability calculations are included as attachments to this report. Although both safety and reliability trees have been constructed for the PDU, the verification and analysis of these trees were not completed as a result of the curtailment of the demonstration plant project. Certain items not completed for the PDU risk and reliability assessment are listed. 

Hazard identification provides information on situations or chemicals tliat can potentially liann tlie environment, life, or property. Tlie processes described are process checklist, event tree, hazard and operability study. 

The degree of confidence in the final estimation of risk depends on variability, uncertainty, and assumptions identified in all previous steps. The nature of the information available for risk characterization and the associated uncertainties can vary widely, and no single approach is suitable for all hazard and exposure scenarios. In cases in which risk characterization is concluded before human exposure occurs, for example, with food additives that require prior approval, both hazard identification and hazard characterization are largely dependent on animal experiments. And exposure is a theoretical estimate based on predicted uses or residue levels. In contrast, in cases of prior human exposure, hazard identification and hazard characterization may be based on studies in humans and exposure assessment can be based on real-life, actual intake measurements. The influence of estimates and assumptions can be evaluated by using sensitivity and uncertainty analyses. - Risk assessment procedures differ in a range of possible options from relatively unso-... 

Hazards identification and risk assessment studies can be performed at any stage during the initial design or ongoing operation of a process. If the study is performed with the initial design, it should be done as soon as possible. This enables modifications to be easily incorporated into the final design. 

The hazards identification procedures presented in chapter 10 include some aspects of risk assessment. The Dow F EI includes a calculation of the maximum probable property damage (MPPD) and the maximum probable days outage (MPDO). This is a form of consequences analysis. However, these numbers are obtained by some rather simple calculations involving published correlations. Hazard and operability (HAZOP) studies provide information on how a particular accident occurs. This is a form of incident identification. No probabilities or numbers are used with the typical HAZOP study, although the experience of the review committee is used to decide on an appropriate course of action. 

Ladies, G.S. et al., Possible incorporation of an immunotoxicological functional assay for assessing humoral immunity for hazard identification purposes in rats on standard toxicology study, Toxicology, 96, 225, 1995. 

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