Hazard analysis terminology

The hazard analysis is often referred to as hazard eharaeterization. No matter what terminology is used, the idea is to determine what the... 

The terminology used varies considerably. Hazard identification and risk assessment are sometimes combined into a general category called hazard evaluation. Risk assessment is sometimes called hazard analysis. A risk assessment procedure that determines probabilities is frequently called probabilistic risk assessment (PRA), whereas a procedure that determines probability and consequences is called quantitative risk analysis (QRA). 

For Step 2—Assess the Risks—a Risk Assessment Matrix is provided. Its configuration is unusual and it does not duplicate well. The terminology used in the matrix for probability and severity, and for the risk gradings, is identical to that in Table 10 in Chapter 8, A Primer on Hazard Analysis and Risk Assessment, with one exception. In the Handbook, M is the designation for Medium Risk, rather than Moderate Risk. We here include Table 10 from Chapter 8 as Table 3. 

The terms job hazard analysis QHA) and job safety analysis (JSA) are used somewhat interchangeably. A variety of other terminology such as job task analysis (JTA), activity task analysis (ATA), and others are used depending on the industry and organization. 

OECD/IPCS (2001) Project on the harmonization of chemical hazard/risk assessment terminology Critical analysis of survey results. Organisation for Economic Co-operation and Development and World Health Organization, International Programme on Chemical Safety (in press). 

In the terminology of QRA, consequence is a measure of the expected outcome of an event and is measured or expressed as hazard distances or hazard zones. The impact analysis addresses the potential effects of the hazardous consequences to people, property, and the environment. A consequence analysis is normally carried out using mathematical models and computer software addressing the physical and chemical phenomena. Impact analysis takes into account the presence of people, property, and sensitive environments that can be adversely be affected by a chemical release. 

According to the ISO/IEC Guide 51 1999, risk evaluation is defined as a wide process of estimation and analysis. In its terminology risk analysis is defined as the systematic use of information to identify hazards and estimate risk, and the risk estimation is defined as a procedure to determine if the risks are tolerable or not. In this manner ISO/IEC Guide 51 1999 presents a iterative process model to evaluate and reduce risks that can be applied to qualitative and quantitative risk evaluations, as shown in Fig. 1. 

The more complex the system or process to be evaluated, the more essential is the need for a HAZOP study. The HAZOP study is conducted in much the same way as the what-if analysis, usually by the same review team. There are minor differences, however, in terminology and approach. In the HAZOP study, certain guidewords are normally used to aid the review team and help identify specific areas where deviations from design intent can occur. Guidewords can include pressure, flow, level, temperature, and power. HAZOP also attempts to identify the severity of the outcome if such deviations from the norm occur as well as the probability or likelihood of occurrence. The hazard risk matrix established and explained in Chapter 2 (Table 2.3) can be used for this purpose since it provides both severity and probability rankings for a given hazardous situation. 

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