Qualitative risk analysis

Chlorine Railcar Tank Truck Higher Escalation - Qualitative Risk Analysis 

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Step f considers all of the background information discussed in Section 2.f. If the information requirement is based on a regulatory concern or a special purpose need, then Steps 2 through 5 are bypassed and a QRA should be performed. If the information is needed for decision making, you must determine whether the significance of the decision warrants the expense of a QRA. If not, you may be able to use less resource-intensive qualitative approaches to satisfy your information requirements. Table 8 contains examples of typical conclusions reached from qualitative risk analysis results. 

CPQRA is their acronym for Chemical Process Qualitative Risk Analysis... 

AIChemE (2001) Guidelines for Chemical Processes Qualitative Risk Analysis, 2nd edn (Center for Chemical Process Safety, American Institute of Chemical Engineers, New York). 

The results of the prioritization process are detailed in Table 3.5. Three activities have been ranked as Lower Risk and will be dropped from further consideration. These chemicals have been ranked as lower risk because the concentration of aqueous ammonia and formaldehyde in combination with a small shipment volume presents only a minor enviromnental impact potential. Additionally, methyl bromide is used at some facilities, but it is received in small cylinders that have only a localized impact potential if released while in transit. These chemicals and modes of transport will, however, continue to be reviewed and monitored as part of the global risk management program, including a primary management system review. The remaining chemical and modes of transport will be escalated for qualitative risk analysis. 

Table 4.2 provides a checklist of some of the information that can be collected as part of a qualitative risk analysis. This checklist is intended to be a starting point for identifying issues that may require further evaluation. It is included in Appendix B, on the enclosed CD, and should be altered, shortened, or expanded to meet the needs of yom particular operation. 

At this point in the example, the eompany-wide reviews eompleted in Chapters 2 and 3 are replaeed with a first-level qualitative risk analysis foeused on the transportation aetivities of a single XYZ Cheinieal faeihty. To eontinue the example, a single XYZ Chemical facility is selected. This facility will continue to be evaluated as the level of analysis detail increases from qualitative to semi-quantitative in this chapter to quantitative risk analysis (Chapter 5). As the level of detail increases, the analysis will be directed at specific questions that remain following each level of analysis. This facility will continue to be the focus of Chapter 6 where the security vulnerabihty of the hazardous materials in transit is evaluated. Chapter 7 where risk reduction options are evaluated, and Chapter 8 where the ongoing management of risk continues in the future. 

The site-level health and safety manager was given notice from corporate for the need to conduct the qualitative risk analysis of the plant s hazardous material transportation operations. The safety manager was provided with a questiotmaire regarding all chemicals of concern, shipping quantities, modes of transit, and the route characteristics (similar to the checklist found in Table 4.2). This information was transmitted back to corporate for analysis, which included a corporate-level comparison to the other XYZ Chemical facihties risk results. Based on the information collected at the site level, the following was determined and reviewed by corporate for this facility ... 

Table 4.4 summaries the results of the qualitative risk analysis. Three of the raw materials operations (chlorine, butadiene, and acrylonitrile) and three of the products/wastes (chlorine cylinders, herbicides, and aqueous HCl) were screened out for further risk analysis. Therefore, four chemical movements were escalated for a more detailed semi-quantitative risk analysis... 

Qualitative Risk Analysis (Chapter 4) Facility Levei Asian facility transports chemicals escalated for detailed risk analysis Based on benchmarking, implement bulk chlorine U.S. and European practice as a corporate standard... 

Semi- Quantitative Risk Analysis (Chapter 4) Faciiity Levei Qualitative risk analysis resulted in the escalation of four of the nine chemical/ mode transportation operations from the Asian facility Increased detail resulted in screening out two of the chemical movements Bulk chlorine and pesticide recommendations developed Rerouting Repackaging... 

Qualitative Risk Analysis Based primarily on description and comparison nsing historical experience and engineering jndgment, with httle quantification of the hazards, consequences, likelihood, or level of risk. 

In the following, we will first deseribe the related regulatory issues. Then, we will present the basic approach to performing qualitative risk analysis based on Bayesian Belief Network (BBN) to identify unnecessary conservatism. A ease study dealing with the issue of independent verifieation and vahdation (IV V) will then be diseussed, followed by a eonclusion. 

Qualitative risk analysis Use of tools to identify the probability and potential outcomes to identify high, moderate, and low risk conditions to set priorities for response planning. (Adapted from PMBOK Guide — 2000 edition)... 

A pass or fail fit test in which the respirator wearer assesses the fit of the respirator by being subjected to a challenge agent that can be adequately detected by the senses. Qualitative Risk Analysis... 

An evaluation of both the frequency and the consequences of potential hazardous events to make a logical decision on whether the installation of a particular safety measure can be justified on safety and loss control grounds. Frequency and consequences are usually combined to produce a measure of risk, which can be expressed as the average loss per year in terms of injury or damage arising from an incident. The risk calculations of different design alternatives can be compared to determine the safest and most economical options. Calculated risk may be compared to set criteria that have been accepted by society or required by laws. See also Qualitative Risk Analysis. 

It is not possible to quantify all risks. In many cases, qualitative risk analysis is the best available. One can use a classification scheme such as that shown in Figure 34-1. Table 34-4 and Table 34-5 provide a similar scheme. An analyst assigns one of five probability categories from Table 34-4 and one of four severity categories from Table 34-5. This scheme leaves out quantities completely. Analysts need considerable judgment to apply the categories consistently. 

Risk Anatysis. This step is split into two parts qualitative risk analysis and quantitative risk analysis. Qualitative risk analysis involves prioritizing identified risks for further action. This helps identify high-priority risks and ensures that these risks are dealt with first. Factors used for prioritizing risks include their probabUity of occurring and the mt nitude of their impact if they do occur, as well as when they are... 

The quantitative risk analysis process uses the prioritized list of risks produced by qualitative risk analysis to analyze the effect of the listed risks and assign a numerical rating to those risks. These ratings help in assessing the probability and impact of the identified risks. Quantitative risk analysis also creates an overall risk score that is applicable to the situation. 

To identify all hazards and consider persons at risk, it is necessary to follow good practice (i.e., to follow standards, statues), otherwise there is no need to carry on. To check if there will be any major risk if no, qualitative risk analysis, and then finally to consider if further analysis is at all required. 

From Clause 4-3.3 it is clear that the most common form of qualitative risk analysis is the risk matrix and risk ranking (Chapter I). Generally, preliminary hazard analysis (Clause 4.0 of Chapter I) is done to obtain rough knowledge about the risk profile for... 

A system is a part of the universe within a certain domain in space and time. What is an environment Outside the frontier of the system is the environment [1], Here, system shall have an identity, that is, deterministic. There shall be an external boundary to the system. An external boundary is determined by what aspect of system performance is of concern. This is stated here because for quantitative hazard analysis, boundary definition is extremely important. Also, the interface part needs to be considered (See Fig. V/3.0-l). The process definition for qualitative risk analysis is Qualitative Risk Analysis assesses the priority of identified risks using their probability of occurring, the corresponding impact [...] as well as other factors such as the time frame and risk tolerance [..On the contrary, quantitative risk analysis (QRA) as per DNV is Typically, a QRA can be defined as the formal and systematic approach of identifying potentially hazardous events, estimating the likelihood and consequences of those events, and expressing the results as risk to people, the environment or the husiness. ... 

Municipal RVAs in Norway are typically performed using a method best covered by the label coarse risk analysis, which is described by Aven (2009) as a qualitative risk analysis method that can be carried out with relatively modest effort. This is consistent with the recommended method in the existing guideline on municipal RVAs (NDCP 1994). 

In a qualitative risk analysis, probability categories must be defined. One such definition (Brauer 1990, p. 530) includes the following categories ... 

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